Practice MCQsBuild a paperTopical banksYearly papersBuild a paperPricing
Topical›Biology 9700›Biological molecules›Proteins›Paper 1

Proteins — Paper 1 · A Level Biology 9700

2.3· 261 questions · 261 marks · 313 min · 2004–2025· Multiple choice

Every Cambridge A Level Biology Paper 1 question on proteins, laid out as 83 A4 pages with the mark scheme below. Nothing is left out. Free to read, no account.

QuestionsMark scheme
Different topic or paper

Questions83 pages

Question 1: Which term describes the type of bonding responsible for stabilising the secondary structure of a protein? A disulphide B hydrogen C hydrop…Question 2: How many different polypeptides, each consisting of r amino acids, can be made if the number of different amino acids available is n ? n r …Question 3: At which levels of protein structure do hydrophobic interactions occur? A primary, secondary and tertiary B primary, secondary, tertiary an…Question 4: The diagram shows a dipeptide. Which bond is the peptide bond? A B C D R1 O R2 H O N C C N C C H H H H OHQuestion 5: Which statement is true for cellulose, but not true for protein? A It is found in cell surface membranes. B It is synthesised from identica…Question 6: Which level of protein structure maintains the globular shapes of enzymes? A primary B secondary C tertiary D quaternary1 / 83
Question 7: Which type of bond is involved in maintaining primary, secondary and tertiary structure in protein molecules? level of structure primary se…Question 8: What is the function of iron in the haemoglobin molecule? A It binds oxygen to the haemoglobin molecule. B It makes the haemoglobin more so…Question 9: When solutions of dilute sodium hydroxide and copper(II) sulphate (biuret test) were added to an unknown substance, a purple colour was obs…Question 10: The diagram shows part of a macromolecule in the form of triple helices, lying side by side with covalent cross links between them. What is…2 / 83
Question 11: The diagrams show four different molecules. P Q CH2OH CH2OH C O H O H H N C C H C C H OH OH H H HO OH C C H OH R S CH2OH O OH C O C H OH H …Question 12: How is the shape of a polypeptide chain maintained when it is coiled into an α helix? A disulphide bonds B hydrogen bonds C hydrophobic int…Question 13: What will break an ionic bond between amino acids? A condensation B hydrolysis C low temperature D pH changeQuestion 14: When hydrolysed, which molecules have products containing a carboxyl group? 1 phospholipids 2 polysaccharides 3 proteins A 1 and 2 B 1 and …3 / 83
Question 15: Which substances contain carbon, hydrogen, oxygen and nitrogen? 1 amylopectin 2 collagen 3 deoxyribonucleic acid A 2 only B 1 and 2 only C …Question 16: A number of different types of bonds maintain the structure of proteins. These include disulphide, hydrogen and ionic bonds, as well as hyd…Question 17: Haemoglobin is a globular protein consisting of four polypeptide chains – 2 alpha chains and 2 beta chains. In normal individuals, in the D…Question 18: Which type of molecule contains disulphide bonds and which contains glycosidic bonds? disulphide bonds glycosidic bonds A glycoprotein poly…4 / 83
Question 19: Which combination of bond types correctly shows the weak and strong bonds that hold a molecule of protein in shape? types of bond hydrogen …Question 20: Which statement is true for cellulose, but not true for protein? A It is found in cell surface membranes. B It is synthesised from identica…Question 21: The diagram shows a tripeptide molecule. H H O H C C C OH H H NH 1 H O H H C C C C 2 O H H 3 NH H H H C C C 4 O H NH2 At which two points w…Question 22: HIV-1 protease is an enzyme produced by the HIV virus. Two identical chains of 99 amino acids form the enzyme. In each chain, amino acids 2…5 / 83
Question 23: Which features of collagen result in it having high tensile strength? 1 covalent bonds form between adjacent molecules 2 each three-strande…Question 24: Which feature of haemoglobin makes it a globular protein? A It has four cross-linked polypeptide chains forming a quaternary structure. B I…Question 25: The enzyme lysozyme secreted from tear glands forms deposits on contact lenses. Which ingredient would be effective in a contact lens clean…Question 26: Which feature of haemoglobin makes it a globular protein? A It has four cross-linked polypeptide chains forming a quaternary structure. B I…6 / 83
Question 27: The enzyme lysozyme secreted from tear glands forms deposits on contact lenses. Which ingredient would be effective in a contact lens clean…Question 28: The enzyme lysozyme secreted from tear glands forms deposits on contact lenses. Which ingredient would be effective in a contact lens clean…Question 29: Which feature of haemoglobin makes it a globular protein? A It has four cross-linked polypeptide chains forming a quaternary structure. B I…Question 30: A peptide bond is formed between atoms of which two elements? A carbon and carbon B carbon and hydrogen C carbon and nitrogen D hydrogen an…Question 31: Which features affect the tensile strength of collagen? 1 the helical structure of collagen chains 2 the small R group of the amino acids i…7 / 83
Question 32: An amino acid can be represented as H R O N C C H H OH where R represents a variable side chain. Which is not a possible side chain? A CH3 …Question 33: Which set of statements correctly describes haemoglobin? A four polypeptide iron ions can in each chain, at 50 % saturation, chains, each a…Question 34: Which rows show the chemical groups present in the biological molecules listed? biological presence of carboxyl presence of two or more mol…8 / 83
Question 35: Which correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride? structure molecule held …Question 36: Which levels of protein structure can determine the specificity of an enzyme? 1 primary 2 secondary 3 tertiary 4 quaternary A 1, 2, 3 and 4…Question 37: At which levels of protein structure do ionic bonds occur? 1 secondary 2 tertiary 3 quaternary A 1 and 2 only B 1 and 3 only C 2 and 3 only…Question 38: Myoglobin is a protein with a similar function to haemoglobin. However, myoglobin does not have a quaternary structure. Why does myoglobin …9 / 83
Question 39: The diagram shows the structure of the amino acid cysteine. H H H N H S C C C OH H H O When two of these amino acids join together what bon…Question 40: Which rows show the chemical groups present in the biological molecules listed? biological presence of carboxyl presence of two or more mol…Question 41: Which correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride? structure molecule held …10 / 83
Question 42: Which set of statements correctly describes haemoglobin? A four polypeptide iron ions can in each chain, at 50 % saturation, chains, each a…Question 43: Which is the strongest type of bonding found in proteins? A disulfide bonds B hydrogen bonds C hydrophobic interactions D ionic bondsQuestion 44: Which is the strongest type of bonding found in proteins? A disulfide bonds B hydrogen bonds C hydrophobic interactions D ionic bondsQuestion 45: Which level of protein structure maintains the globular shapes of enzymes? A primary B secondary C tertiary D quaternary11 / 83
Question 46: Which substances contain carbon, hydrogen, oxygen and nitrogen? 1 collagen 2 amylopectin 3 deoxyribonucleic acid A 2 only B 1 and 3 only C …Question 47: Which molecules contain C=O bonds? 1 amino acids 2 fatty acids 3 proteins A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3Question 48: Which substances contain carbon, hydrogen, oxygen and nitrogen? 1 collagen 2 amylopectin 3 deoxyribonucleic acid A 2 only B 1 and 3 only C …Question 49: Which level of protein structure maintains the globular shapes of enzymes? A primary B secondary C tertiary D quaternary12 / 83
Question 50: Which row is correct for each of the molecules? β-glucose collagen haemoglobin sucrose A hexose sugar structural contains the formed by wit…Question 51: Which molecules contain C=O bonds? 1 amino acids 2 fatty acids 3 glycerol A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3Question 52: Which molecules have a structural formula that contains C=O bonds? 1 glucose 2 glycerol 3 protein A 1 and 2 only B 1 and 3 only C 2 and 3 o…13 / 83
Question 53: Haemoglobin consists of two α chains and two β chains. Approximately 5 % of all humans have one amino acid in the β chain different from no…Question 54: Which row shows the types of bond found at different levels of protein structures? bonds level of protein structure peptide | hydrogen | i…Question 55: What describes a globular protein that is not soluble in water? A having amino acids with hydrophilic R groups facing out B having amino ac…Question 56: Features of four proteins, W, X, Y and Z, are described below. W consists of two polypeptides held together by disulfide bonds X consists o…14 / 83
Question 57: The R groups (side chains) of amino acids can be hydrophobic, hydrophilic, acidic or basic. The diagram shows four different amino acid R g…Question 58: Which molecules contain a carboxyl group? 1 amino acid 2 glycerol 3 saturated fatty acid 4 unsaturated fatty acid A 1 and 2 only B 3 and 4 …Question 59: The diameter of some atoms when they form bonds are given in the table. single bond double bond atom / nm / nm H 0.060 – O 0.132 0.110 N 0.…15 / 83
Question 60: Two solutions, 1 and 2, one containing starch and sucrose, and the other containing glucose and protein, were tested with a variety of reag…Question 61: What occurs during protein denaturation by extremes of pH? 1 breakage of peptide bonds leading to loss of shape of active site 2 disruption…Question 62: Collagen is a macromolecule with three polypeptides lying closely side by side in the form of a triple helix. Every third amino acid in eac…16 / 83
Question 63: The diagrams show the structures of two amino acids, each of which has two amine (–NH2) groups. 1 2 4 5 H2N CH COOH H2N CH COOH CH2 CH2 3 C…Question 64: Each list, 1, 2 and 3, shows some substances found in animal tissues. 1 glucose, cholesterol, triglycerides, water. 2 glycogen, antibodies,…Question 65: A student wrote down three statements about antibodies. 1 Their structure depends on peptide, hydrogen and disulfide bonds. 2 They are prot…17 / 83
Question 66: The formation of glycosidic and peptide bonds is responsible for polymerisation in some biological molecules. Which bonds are found in whic…Question 67: The diagrams show the structures of two amino acids, each of which has more than one amine (–NH2) group. 1 2 4 H2N CH COOH H2N CH COOH CH2 …Question 68: Which explains why haemoglobin is able to carry oxygen? A It consists of four polypeptides. B It contains iron. C It has a quaternary struc…18 / 83
Question 69: The diagrams show the structures of two amino acids, each of which has more than one amine (–NH2) group. 1 3 4 H2N CH COOH H2N CH COOH CH2 …Question 70: Which combination of bond types correctly shows the weak and strong bonds that hold a molecule of protein in shape? types of bond hydrogen …Question 71: The diagram shows the structure of four amino acids in solution. COO– COO– H C H3N+ CH2 CH2 CH2 CH2 C N+H3 N+H3 H H glycine lysine COO– O C…19 / 83
Question 72: Which level of organisation of a haemoglobin molecule is coded by a DNA molecule? A primary structure B secondary structure C tertiary stru…Question 73: Which molecule contains a glycosidic bond? A B H H O OH HO CH2 C C H C O C R H O O N CH3 CH2 C C H H C O C R H O O N CH3 C C H H C O C R O …Question 74: The diagrams show the structures of two amino acids, each of which has two carboxylic acid (–COOH) groups. 1 3 4 H2N CH COOH H2N CH COOH CH…20 / 83
Question 75: What is the correct sequence for the processes involved in the formation of an enzyme in a cell? A transcription → condensation → translati…Question 76: Which comparative statements concerning biological molecules are correct? 1 A collagen molecule is a fibrous protein that contains many ami…Question 77: The diagram represents an amino acid. H R O N C C H H OH R represents a variable side chain. Which is not a possible side chain? A CH3 B CH…Question 78: One type of antigen is formed by a reaction between two different molecules. Apart from oxygen, which other elements are found in this anti…21 / 83
Question 79: The growth of crop plants is often limited by the availability of nitrogen in the soil. The graph shows the results of an investigation int…Question 80: Which correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride? structure molecule held …22 / 83
Question 81: The diagram shows the relationship between the levels of protein structure and bonds. 1 2 3 4 5 Which row is correct? 1 2 3 4 5 A primary p…Question 82: Which of the bonds stabilising the tertiary structure of a protein would be least likely to break when the temperature is increased above t…Question 83: The diagram shows the structure of four amino acids in solution. COO– COO– H C H3N+ CH2 CH2 CH2 CH2 C NH3 + NH3 + H H glycine lysine COO– O…23 / 83
Question 84: Which words from the table correctly complete the paragraph about enzymes? When the pH of an environment is decreased below an enzyme’s opt…Question 85: The enzyme lactase is found in the membranes of epithelial cells lining the small intestine. The enzyme is formed by a single polypeptide t…Question 86: Which of the following terms can be used to describe the secondary structure of a protein? 1 dipeptide 2 specific order of amino acids 3 α-…Question 87: Why is haemoglobin stated to have a quaternary structure? A It has four haem groups. B It has two or more polypeptide chains. C It is coile…24 / 83
Question 88: The diagrams show different types of bond found in biological molecules. 1 2 3 O NH O CH2 S S CH2 C N H 4 5 NH2 + O– O C CH2 C C CH2 C C O …Question 89: Which description is correct? A A collagen molecule has a high proportion of the amino acid glycine, which has a very small side chain. B A…Question 90: Which type of bond holds together an α-helix or β-pleated sheet of a protein? A disulfide B hydrogen C ionic D peptideQuestion 91: What describes only the quaternary structure of haemoglobin? 1 α-helix 2 a dipeptide 3 a globular structure 4 the specific order of amino a…25 / 83
Question 92: In a ribosome, which bond holds together two adjacent amino acids? A disulfide B hydrogen C ionic D peptideQuestion 93: The diagram shows the three dimensional structure of collagen. Which labelled part represents a molecule of collagen? C B D AQuestion 94: Which type of bond does not hold together the tertiary structure of a protein? A disulfide B hydrogen C hydrophobic interactions D peptideQuestion 95: The protein glutenin gives bread dough its elasticity. The diagram represents a polypeptide of glutenin. tightly tightly coiled coiled regi…26 / 83
Question 96: The diagrams show the amino acid serine. Which circled area is different in all other amino acids? A B H H H H N H N H HO C C C OH HO C C C…Question 97: The synthesis of biological molecules requires the formation of bonds. Which row is correct? a bond forms between a β-1,4 bond forms the h…Question 98: High concentrations of urea break all bonds, except covalent bonds, in protein molecules. Which level of protein structure would remain unc…27 / 83
Question 99: Haemoglobin, a globular protein, consists of four polypeptide chains, two alpha chains and two beta chains. In normal individuals, in the D…Question 100: When proteins are mixed with some organic solvents, hydrophobic interactions and hydrogen bonding are changed in the protein molecules. Wh…Question 101: The diagrams show the structures of two amino acids, one of which has two amine (–NH2) groups and the other has two carboxylic (–COOH) grou…28 / 83
Question 102: Proteins which transport sugars out of cells have been identified. These proteins are called SWEETs. Each SWEET has seven coiled, cylindric…Question 103: Which biological molecules always contain the element nitrogen? A amino acids, cellulose, mRNA B amino acids, DNA, lipids C enzymes, mRNA, …Question 104: Which statement about the quaternary structure of proteins is correct? A consists of four subunits B depends on the presence of metal ions …29 / 83
Question 105: Which set of statements correctly describes haemoglobin? A in each chain, at 50 % saturation, four polypeptide iron ions can hydrophobic R …Question 106: The diagrams show different types of bond found in biological molecules. 1 2 3 O NH O C CH2 S S CH2 C N H 4 5 NH3 + O– O C C C CH2 C C CH2 …Question 107: Which of the bonds will be last to break as the temperature of an enzyme is increased? A hydrogen B hydrophobic interactions C ionic D pept…30 / 83
Question 108: What could describe the tertiary structure of a protein? 1 α-helix 2 a globular structure 3 the specific order of amino acids 4 a specific …Question 109: Which row is correct for each of the molecules? collagen haemoglobin sucrose A has a structural contains the formed by function, found in e…31 / 83
Question 110: Threonylvaline is a dipeptide formed from the two amino acids, threonine and valine. A peptide bond forms between the carboxyl group of thr…Question 111: Which feature explains why haemoglobin is soluble? A All four polypeptide chains are linked together to form a spherical molecule. B Each p…Question 112: Some of the molecules found in animal tissues are grouped into three lists. 1 glucose, cholesterol, triglycerides, water 2 glycogen, antibo…32 / 83
Question 113: Haemoglobin consists of two α chains and two β chains. Approximately 5% of all humans have one amino acid in the β chain that has been chan…Question 114: Which row gives the correct description of both a collagen molecule and a collagen fibre? collagen molecule collagen fibre A α and β polype…Question 115: The diagrams show the structures of two amino acids, each of which has two amine (–NH2) groups. 1 2 4 5 H2N CH COOH H2N CH COOH CH2 CH2 3 C…33 / 83
Question 116: The diagram shows the molecular structure of a peptide. O NH2 C CH2 H O CH3 H H C N C C OH N C C N C H H H O CH2 H O OH Which molecules wou…34 / 83
Question 117: The diagram shows a haemoglobin molecule. β-globin chain 3 α-globin chain 4 2 α-globin chain β-globin chain 1 Which row identifies the diff…Question 118: Boiling the bones and teeth from dead animals can be used to produce a type of glue. The glue is formed from the collagen fibres present in…35 / 83
Question 119: What describes the primary structure of a protein? A α-helix B a dipeptide C a globular structure D the specific order of amino acidsQuestion 120: The diagram shows some of the relationships between cellulose, collagen and haemoglobin. 1 2 3 4 5 Which row is correct? 1 2 3 4 5 A cellul…Question 121: The diagram shows a protein molecule. globular head key long polypeptide short polypeptide Two long polypeptides each form α-helices for mu…36 / 83
Question 122: A student carried out four tests for biological molecules on a sample of milk. The tests and their results were as follows. ● Heating to 80…Question 123: Which row correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride? structure molecules …Question 124: A polypeptide has a number of amino acids (n). How many peptide bonds and R groups (side chains) does this polypeptide have? A n – 1 peptid…37 / 83
Question 125: The diagram shows the amino acids in a polypeptide. key type of amino acid polar basic polar acidic Asp Arg Lys polar Cys Thr Lys Leu non-p…Question 126: A person with diabetes is unable to make enough of the protein insulin. Some forms of diabetes can be treated by using insulin produced by …38 / 83
Question 127: Which levels of protein structure are maintained by disulfide bonds? A secondary, tertiary and quaternary B tertiary and quaternary only C …Question 128: Which diagram correctly shows the formation of a peptide bond between two amino acids? A B H H O H H O H H O N C C N C C N C C H2O H H C H …Question 129: Which molecules are globular proteins? 1 amylase 2 haemoglobin 3 DNA polymerase A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 onlyQuestion 130: When hydrolysed, which molecules have products containing a carboxyl group? 1 phospholipids 2 polysaccharides 3 proteins A 1 and 2 B 1 and …39 / 83
Question 131: The diagram shows relationships between some important molecules and bonds. 1 peptide glycosidic 3 ester 2 triglyceride cellulose vegetable…Question 132: The diagrams show two arrangements of amino acids in a protein. T S Which row correctly names the bonds at S or T? ionic bond hydrogen bond…40 / 83
Question 133: Students were asked to highlight only the R groups of two ring-shaped amino acids. Which pair of diagrams are correct for both amino acids?…Question 134: Which words from the table correctly complete the paragraph about enzymes? When the pH of an environment is decreased below the optimum pH …41 / 83
Question 135: The diagram shows the relationship between some biological molecules. 1 2 3 4 5 Which row is correct? 1 2 3 4 5 A α-glucose carbohydrate su…Question 136: Which molecules contain C=O bonds? 1 amino acids 2 fatty acids 3 glycerol A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 onlyQuestion 137: Which row describes a collagen molecule? bonds stabilising properties primary structure helix the molecule A disulfide high temperatures hi…Question 138: Which molecules contain the following bonds? ester hydrogen disulfide A amylase haemoglobin catalase B glycerol glycogen collagen C lipids …42 / 83
Question 139: Which description is correct for collagen? A A collagen molecule has a high proportion of the amino acid glycine, which has a very small R …Question 140: Which statements about a peptide bond are correct? 1 It joins two monomers which are always identical to each other. 2 It contains four dif…Question 141: Which statements about the primary structure of a protein are correct? 1 It may be branched. 2 It is determined by the sequence of DNA base…43 / 83
Question 142: The diagram shows a glycoprotein embedded in the cell surface membrane of a human red blood cell. This glycoprotein is part of a system of …Question 143: Which diagram shows where a peptide bond would be formed? A B H R O H R O H R O O R H N C C N C C N C C C C N H H OH H H OH H H OH H O H H …44 / 83
Question 144: Which statements about collagen molecules are correct? 1 Both types of secondary structure occur within the molecules. 2 Large numbers of h…Question 145: The protein glutenin gives bread dough its elasticity. The diagram represents a polypeptide of glutenin. tightly tightly coiled coiled regi…Question 146: The table shows the diameter of some atoms when they form bonds. single bond double bond atom / nm / nm H 0.060 – O 0.132 0.110 N 0.140 0.1…45 / 83
Question 147: Some animals produce antimicrobial proteins which protect them from pathogens. These proteins could be used to kill human pathogens, howeve…Question 148: The table compares three molecules, X, Y and Z, which contain the elements carbon, hydrogen and oxygen only. The percentage of carbon, hydr…Question 149: Which levels of protein structure can determine the specificity of an enzyme? 1 primary 2 secondary 3 tertiary 4 quaternary A 1, 2, 3 and 4…Question 150: What is the minimum number of carbon atoms in an amino acid? A 1 B 2 C 3 D 446 / 83
Question 151: Which diagram shows the formation of a peptide bond? A B H H O H H O H H O O H H N C C N C C N C C C C N H H OH H H OH H H OH HO H H H2O H2…Question 152: In enzyme-catalysed reactions, the position of the amino acids found at the active site is important. During the synthesis of enzymes, ami…Question 153: Which features affect the tensile strength of collagen? 1 the helical structure of collagen chains 2 the small R group of the amino acids i…47 / 83
Question 154: Which features of collagen result in it having high tensile strength? 1 Bonds form between adjacent molecules. 2 Each three-stranded molecu…Question 155: Which levels of protein structure would always be changed if an enzyme works by the induced fit hypothesis? primary secondary tertiary qua…Question 156: Which statements could be used to describe enzyme molecules and antibody molecules? 1 Hydrogen bonds stabilise the structure of the protein…Question 157: Which rows show the chemical groups present in the biological molecules listed? biological presence of carboxyl presence of two or more mol…48 / 83
Question 158: Fibrous proteins are composed of chains of amino acids held together by bonds. An example of part of a fibrous protein is shown. O R H N N …Question 159: Which row about the structure of proteins is correct? primary structure secondary structure quaternary structure A is the number is the lef…49 / 83
Question 160: Three proteins that have a quaternary structure are listed. • Type IX collagen is formed from three different polymers. • The main form of …Question 161: The diagrams show the structure of an amino acid with some parts of the molecule shaded. Which diagram shows the shaded part of the molecul…50 / 83
Question 162: The diagrams show three examples of different bonds. bond 1 bond 2 bond 3 O NH O C C N CH2 S S CH2 H Which bonds hold the secondary structu…Question 163: Which molecules contain at least two double bonds? 1 unsaturated fatty acid 2 collagen 3 haemoglobin A 1, 2 and 3 B 1 and 2 only C 1 and 3 …Question 164: The diagram shows a protein molecule. globular head key long polypeptide short polypeptide Two long polypeptides each form α-helices for mu…51 / 83
Question 165: Which types of bond will keep a folded protein in its precise shape for the longest time as the temperature rises? A disulfide B hydrogen C…Question 166: What occurs during the formation of a peptide bond between two amino acids? A OH is removed from COOH and H is removed from an R group. B O…52 / 83
Question 167: The diagram shows a small part of a polypeptide. CH3 CH3 H O CH H CH N C CH N C CH N C H H O CH CH3 O CH2 CH3 What would the products be if…53 / 83
Question 168: The enzyme trypsin hydrolyses proteins to amino acids. Trypsin does not function when the pH is very low as its 3D shape would be changed. …Question 169: The flow chart shows some of the steps in the formation of collagen. three polypeptide chains held together by X bonds triple helix held to…Question 170: Which molecules contain at least two double bonds? 1 saturated fatty acid 2 collagen 3 haemoglobin A 1, 2 and 3 B 1 and 2 only C 1 and 3 on…Question 171: Which molecules are formed by condensation which involves a carboxyl group? A amylopectin, collagen, triglyceride, sucrose B amylopectin, c…54 / 83
Question 172: Which row correctly matches the function with the structural features of cellulose, collagen, glycogen or triglyceride? structure molecul…55 / 83
Question 173: The diagram shows the amino acids in a polypeptide. key type of amino acid polar basic polar acidic Asp Arg Lys polar Cys Thr Lys Leu non-p…56 / 83
Question 174: A student carried out tests for biological molecules on the same sample of milk. The tests and their results were as follows. ● Heating to …Question 175: Adult human haemoglobin typically consists of two  chains and two  chains. Approximately 5% of humans have one amino acid in the  chain …Question 176: Lysozyme occurs in human tears, saliva, milk and mucus. Lysozyme has a role in the immune system and hydrolyses peptidoglycan. Which descri…Question 177: Which statement about collagen is correct? A Tissues containing collagen fibres cannot stretch. B Each polypeptide chain forms an alpha hel…57 / 83
Question 178: Which pair of molecules only includes macromolecules that can be found in animal cells? A amylase and amylopectin B collagen and glycogen C…Question 179: Which description of collagen is correct? A A collagen molecule consists of three polypeptide chains, each in the shape of a helix. The thr…Question 180: In a healthy human, the mean value for the number of haemoglobin molecules in one red blood cell is 260 million. How many -globin chains d…Question 181: Which statements about a peptide bond are correct? 1 It joins two monomers which are always identical to each other. 2 It contains four dif…Question 182: Which molecule contains the smallest number of hydrogen atoms? A -glucose B glycine, an amino acid in which the R group is H C glycerol D …Question 183: Which molecules contain at least three double bonds? A saturated fatty acid, collagen and haemoglobin B collagen and saturated fatty acid C…58 / 83
Question 184: The diagrams show the structures of two amino acids. One contains two amino (–NH2) groups, labelled 1 and 2. The other contains two carboxy…Question 185: Which row about the structure of proteins is correct? primary structure secondary structure tertiary structure quaternary structure A is th…Question 186: The diagrams show three examples of different bonds. bond 2 bond 1 bond 3 O NH O C C N CH2 S S CH2 H Which bonds hold the tertiary structur…59 / 83
Question 187: Which feature of collagen enables it to fulfil a structural role in skin and in tendons? A Adjacent collagen molecules are linked by ester …Question 188: Which molecules contain at least two double bonds? A saturated fatty acid, collagen and haemoglobin B collagen and saturated fatty acid onl…Question 189: The diagram shows an amino acid. H CH3 O N C C H H OH Which group is changed to produce different amino acids? A OH B C=O C CH3 D NH2Question 190: Which row is correct about the structure of proteins? primary secondary tertiary quaternary A determined by occurs by disulfide, ionic, alw…60 / 83
Question 191: Which tests will identify biological molecules that contain monomers with a carboxyl group? Benedict’s D A biuret ethanol C BQuestion 192: Which molecules always contain at least four double bonds? A triglyceride, collagen and haemoglobin B collagen and triglyceride only C haem…Question 193: Which row about the structure of proteins is correct? primary structure secondary structure tertiary structure A the number the left-handed…61 / 83
Question 194: Which statement about collagen is correct? A A collagen fibre is made of three parallel helices with hydrogen bonds holding them in place. …Question 195: Which descriptions about all enzymes are correct? 1 catalyse the breakdown of large molecules into smaller molecules 2 only function inside…Question 196: Which row matches each molecule to a type of bond that is present? ester bond hydrogen bond disulfide bond A amylase haemoglobin catalase B…Question 197: The diagrams show three examples of different bonds. bond 2 bond 1 bond 3 O NH O C N CH2 S S CH2 H Which bonds can hold the quaternary stru…62 / 83
Question 198: Which row correctly describes the primary structure, secondary structure, tertiary structure and quaternary structure of some proteins? pri…Question 199: A polypeptide contains a specific number of amino acids, n. How many peptide bonds are present in this polypeptide? A n – 1 B n C n + 1 D n…Question 200: Which statement is correct? A Amylase, ribose and phospholipid are all macromolecules. B Cellulose, glucose and catalase are all polymers. …63 / 83
Question 201: A student used colorimetry to monitor the hydrolysis of a protein by a protease enzyme. The student used biuret solution to determine the c…Question 202: Which statement is correct? A Cellulose, glycogen and amylopectin are all polymers. B Ribose, amylase and phospholipid are all macromolecul…Question 203: The diagram shows two amino acids. Some of the hydrogen atoms are numbered 1 to 6. H H O H H O N C C N C C H H OH H H OH 1 2 3 4 5 6 Which …64 / 83
Question 204: Typical enzymes are large globular proteins with a specific tertiary shape. Which molecular interactions are directly involved in maintaini…Question 205: Which molecule contains at least one peptide bond? A B H H O OH HO CH2 C C H C O C R O H O O N HO C CH2 C C H H C O C R H O O N CH3 C C H H…Question 206: RNA polymerase and peptidyl transferase are both enzymes involved in protein synthesis. Which statements describe similarities between thes…65 / 83
Question 207: The diagram shows a section of a glycoprotein molecule found embedded in a cell surface membrane. Each of the amino acids is represented by…Question 208: Which row correctly matches the example with the type of molecule? disaccharide macromolecule monomer polymer A fructose glycogen glucose s…Question 209: Bread contains a mixture of polypeptides known as gluten. Two of the polypeptides found in gluten are glutenin and gliadin. Which statement…66 / 83
Question 210: A shortage of protein in the diet of children can lead to a disease that causes excess tissue fluid to build up in the abdomen. What explai…Question 211: Silk moth caterpillars have been genetically modified to produce a mixture of their own silk and the much stronger spider silk of the golde…Question 212: Which property of the tertiary structure of a globular protein enables it to catalyse a metabolic reaction? A It has hydrophobic amino acid…Question 213: A student wrote three statements about antibodies. 1 Their structure depends on peptide, hydrogen and disulfide bonds. 2 They are protein m…67 / 83
Question 214: A scientist studying the structure of a protein reported that it consists of two polypeptide chains joined by disulfide bonds. Which featur…Question 215: Which row correctly shows levels of protein structure that can be held together by each type of interaction? hydrophobic hydrogen bonds cov…Question 216: Which molecules contain at least three double bonds? saturated triglyceride C A D collagen B haemoglobinQuestion 217: The diagrams show three examples of different bonds. bond 1 bond 2 bond 3 O NH O C C N CH2 S S CH2 H Which bonds hold the secondary structu…68 / 83
Question 218: Insulin is a globular protein involved in cell signalling. It is transported in the blood plasma from the cells that synthesise it to its t…Question 219: Which molecules contain at least two double bonds? sucrose C A D collagen haemoglobin BQuestion 220: Which part of the structure of haemoglobin carries oxygen? A four polypeptide chains B haem groups C hydrogen bonds D hydrophilic R groupsQuestion 221: Which polymers are present in all viruses, all prokaryotes and all eukaryotes? 1 polynucleotides 2 polypeptides 3 polysaccharides A 1, 2 an…69 / 83
Question 222: Which molecules contain at least four double bonds? unsaturated triglyceride C A D haemoglobin collagen BQuestion 223: The diagram shows the amino acid glutamic acid. COOH H C CH2 CH2 COOH NH2 What is the R group for glutamic acid? A NH2 B H C COOH D CH2 CH2…70 / 83
Question 224: The diagram shows three interactions that hold protein molecules in shape. N H NH3 + O S S interaction 1 interaction 3 C COO– S S interacti…Question 225: Some animals produce antimicrobial proteins which protect them from pathogens. These proteins could be used to kill human pathogens, howeve…Question 226: Which bonds are present in all viruses? 1 phosphodiester 2 peptide 3 covalent A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only71 / 83
Question 227: The diagram represents an amino acid. H R O N C C H H OH R represents a variable side chain. What is not a possible side chain? A CH3 B CH2…Question 228: Which molecules have a structural formula that contains C=O bonds? 1 amino acids 2 fatty acids 3 glycerol 4 protein A 1, 2 and 3 B 1, 2 and…72 / 83
Question 229: The diagram shows the structure of part of a peptidoglycan molecule. H CH2OH H O O H OH H H O H H O O O H CH2OH H3C CH C O NH HC CH3 CO NH …73 / 83
Question 230: The diagrams show the structure of four amino acids in aqueous solution. COO– COO– H C H3N+ CH2 CH2 CH2 CH2 C N+H3 N+H3 H H glycine lysine …Question 231: Collagen molecules are made up of three polypeptide chains interacting together. The individual polypeptide chains consist of a regular pat…Question 232: The masses of the parts of haemoglobin are shown in the table. component mass / Da -globin chain 15 126 -globin chain 15 868 haem group 1…74 / 83
Question 233: The diagram shows a simple metabolic pathway. W  X  Y  Z The letters W, X, Y and Z represent four different substances. At each step in …Question 234: Which statements about peptide bond formation are correct? 1 The bond formation occurs between a carbon of one amino acid and a nitrogen of…Question 235: Which row correctly identifies the weak and strong bonds in the tertiary and quaternary structure of a typical protein? type of bond disulf…75 / 83
Question 236: Which row correctly describes haemoglobin? A four polypeptide iron ions can in each chain, at 50% saturation, chains, each associate with h…Question 237: What cannot occur as a result of a condensation reaction? A breaking of a glycosidic bond B formation of a disaccharide C joining together …Question 238: Which fact about the quaternary structure of proteins is correct? A consists of four polypeptides B depends on the presence of metal ions C…76 / 83
Question 239: The diagrams show parts of three pairs of amino acids within a protein. The pairs are labelled X, Y and Z. X Y Z H H CH3 H3C O O C O O C C …Question 240: The diagram shows part of a collagen fibril made of collagen triple helices. The collagen triple helices are linked to each other by one ty…77 / 83
Question 241: The table shows some information about the polypeptides that make up haemoglobin. -globin -globin total number of amino acid 141 146 resi…Question 242: Which molecules are globular proteins? 1 amylase 2 haemoglobin 3 DNA polymerase A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 onlyQuestion 243: Which description lists all the components of a human haemoglobin molecule? A four polypeptides that are all the same and one haem group B …Question 244: HIV-1 protease is an enzyme produced by the HIV virus. Two identical chains of 99 amino acids form the enzyme. In each chain, amino acids 2…78 / 83
Question 245: Which statements could be used to describe enzyme molecules and antibody molecules? 1 Hydrogen bonds stabilise the structure of the protein…Question 246: Hydroxyproline is synthesised by addition of an –OH group to the R-group of the amino acid proline. Hydroxyproline is a major component of …Question 247: Which levels of protein structure are always involved in forming the active site of an enzyme? level of protein structure primary tertia…Question 248: The diagrams show three different bonds. 1 2 3 O H H N H O C N C S S C H H H Which bonds are found in an antibody molecule? A 1, 2 and 3 B …79 / 83
Question 249: Which molecules contain at least two double bonds? saturated triglyceride C A D collagen haemoglobin BQuestion 250: Which bonds are found in the levels of structure of a protein molecule? primary structure secondary structure quaternary structure A covale…Question 251: Which molecules have products containing a carboxyl group when they are hydrolysed? 1 phospholipids 2 polysaccharides 3 proteins A 1 and 2 …Question 252: Which bonds are involved in maintaining the secondary and tertiary levels of protein structure? 1 disulfide 2 hydrogen 3 ionic secondary te…80 / 83
Question 253: The diagrams show the structure of four amino acids in solution. glycine lysine COO– COO– H C H3N+ CH2 CH2 CH2 CH2 C NH3 + NH3 + H H alanin…Question 254: Histidine and proline are two amino acids commonly found in enzymes. Histidine has a polar R-group and proline has a non-polar R-group. Whe…Question 255: Which molecules contain at least two double bonds? unsaturated fatty acid C A D collagen haemoglobin B81 / 83
Question 256: Which description of globular proteins is correct? A They are only found in cell surface membranes. B They only contain amino acids with hy…Question 257: Which diagram has a covalent bond that joins monomers together to form a biological polymer in eukaryotes? A B C D O R H O R O R R NH3 + –O…Question 258: Which molecules contain at least four double bonds? saturated triglyceride C A D collagen haemoglobin BQuestion 259: In some people a mutation can affect the beta chains in their haemoglobin molecules. As a result polar amino acids on the outer surfaces of…82 / 83
Question 260: Many biological molecules exist as polymers made up of monomer subunits. Which row correctly identifies the monomer in each of the biologic…Question 261: Which descriptions of enzymes that use the lock-and-key hypothesis are correct? 1 The active site is complementary to the substrate the enz…83 / 83

Mark scheme261 answers

Answers below. Sit the paper first if you are practising.

Pastlit

Biology 9700 · Proteins — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

1B1
2A1
3C1
4C1
5B1
6C1
7D1
8A1
9D1
10B1
11D1
12B1
13D1
14B1
15C1
16A1
17B1
18A1
19D1
20B1
21D1
22A1
23B1
24B1
25D1
26B1
27D1
28D1
29B1
30C1
31C1
32D1
33A1
34B1
35A1
36A1
37C1
38D1
39D1
40B1
41A1
42A1
43A1
44A1
45C1
46B1
47D1
48B1
49C1
1 / 6

Pastlit

Biology 9700 · Proteins — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

50D1
51A1
52B1
53C1
54C1
55D1
56C1
57A1
58C1
59B1
60C1
61B1
62C1
63B1
64D1
65B1
66C1
67A1
68B1
69A1
70D1
71C1
72A1
73C1
74A1
75C1
76C1
77D1
78D1
79C1
80A1
81D1
82A1
83B1
84A1
85A1
86D1
87B1
88D1
89A1
90B1
91D1
92D1
93C1
94D1
95D1
96C1
97B1
98A1
2 / 6

Pastlit

Biology 9700 · Proteins — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

99B1
100D1
101A1
102C1
103C1
104C1
105A1
106A1
107—1
108C1
109D1
110A1
111C1
112D1
113C1
114D1
115B1
116C1
117B1
118C1
119D1
120D1
121A1
122C1
123A1
124B1
125D1
126A1
127B1
128A1
129A1
130B1
131A1
132A1
133D1
134A1
135C1
136B1
137C1
138D1
139A1
140D1
141D1
142A1
143A1
144D1
145D1
146B1
147A1
3 / 6

Pastlit

Biology 9700 · Proteins — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

148B1
149A1
150B1
151A1
152B1
153B1
154A1
155D1
156C1
157B1
158B1
159D1
160C1
161B1
162C1
163A1
164A1
165A1
166B1
167D1
168A1
169B1
170D1
171D1
172A1
173D1
174C1
175D1
176C1
177C1
178B1
179D1
180C1
181D1
182B1
183C1
184B1
185D1
186C1
187C1
188C1
189C1
190A1
191—1
192C1
193D1
194B1
195D1
196D1
4 / 6

Pastlit

Biology 9700 · Proteins — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

197C1
198C1
199A1
200C1
201B1
202A1
203B1
204A1
205B1
206B1
207A1
208D1
209D1
210B1
211B1
212C1
213B1
214D1
215C1
216D1
217C1
218C1
219B1
220B1
221B1
222D1
223D1
224B1
225A1
226A1
227D1
228B1
229D1
230C1
231B1
232D1
233C1
234D1
235B1
236A1
237A1
238C1
239B1
240A1
241A1
242A1
243D1
244A1
245C1
5 / 6

Pastlit

Biology 9700 · Proteins — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

246C1
247B1
248A1
249D1
250C1
251B1
252A1
253B1
254D1
255D1
256C1
257D1
258B1
259A1
260A1
261C1
6 / 6
QuestionAnswerMarksFrom
1B19700/11 Oct/Nov 2004
2A19700/11 Oct/Nov 2004
3C19700/11 May/June 2006
4C19700/11 May/June 2006
5B19700/11 Oct/Nov 2006
6C19700/11 Oct/Nov 2006
7D19700/11 Oct/Nov 2006
8A19700/11 Oct/Nov 2006
9D19700/11 Oct/Nov 2007
10B19700/11 Oct/Nov 2007
11D19700/11 Oct/Nov 2007
12B19700/11 May/June 2008
13D19700/11 May/June 2008
14B19700/11 May/June 2008
15C19700/11 Oct/Nov 2008
16A19700/11 Oct/Nov 2008
17B19700/11 Oct/Nov 2008
18A19700/11 Oct/Nov 2008
19D19700/12 Oct/Nov 2009
20B19700/12 Oct/Nov 2009
21D19700/12 Oct/Nov 2009
22A19700/12 Oct/Nov 2009
23B19700/12 Oct/Nov 2009
24B19700/11 May/June 2010
25D19700/11 May/June 2010
26B19700/12 May/June 2010
27D19700/12 May/June 2010
28D19700/13 May/June 2010
29B19700/13 May/June 2010
30C19700/12 Oct/Nov 2010
31C19700/12 Oct/Nov 2010
32D19700/12 Oct/Nov 2010
33A19700/11 May/June 2011
34B19700/11 May/June 2011
35A19700/11 May/June 2011
36A19700/11 May/June 2011
37C19700/12 May/June 2011
38D19700/12 May/June 2011
39D19700/12 May/June 2011
40B19700/13 May/June 2011
41A19700/13 May/June 2011
42A19700/13 May/June 2011
43A19700/11 Oct/Nov 2011
44A19700/13 Oct/Nov 2011
45C19700/11 May/June 2012
46B19700/11 May/June 2012
47D19700/12 May/June 2012
48B19700/13 May/June 2012
49C19700/13 May/June 2012
50D19700/11 Oct/Nov 2012
51A19700/11 Oct/Nov 2012
52B19700/12 Oct/Nov 2012
53C19700/12 Oct/Nov 2012
54C19700/12 Oct/Nov 2012
55D19700/13 Oct/Nov 2012
56C19700/11 May/June 2013
57A19700/12 May/June 2013
58C19700/12 May/June 2013
59B19700/12 May/June 2013
60C19700/13 May/June 2013
61B19700/13 May/June 2013
62C19700/11 Oct/Nov 2013
63B19700/11 Oct/Nov 2013
64D19700/11 Oct/Nov 2013
65B19700/11 Oct/Nov 2013
66C19700/12 Oct/Nov 2013
67A19700/12 Oct/Nov 2013
68B19700/12 Oct/Nov 2013
69A19700/13 Oct/Nov 2013
70D19700/13 Oct/Nov 2013
71C19700/11 May/June 2014
72A19700/11 May/June 2014
73C19700/12 May/June 2014
74A19700/12 May/June 2014
75C19700/12 May/June 2014
76C19700/13 May/June 2014
77D19700/13 May/June 2014
78D19700/13 May/June 2014
79C19700/13 May/June 2014
80A19700/11 Oct/Nov 2014
81D19700/11 Oct/Nov 2014
82A19700/12 Oct/Nov 2014
83B19700/12 Oct/Nov 2014
84A19700/12 Oct/Nov 2014
85A19700/12 Oct/Nov 2014
86D19700/13 Oct/Nov 2014
87B19700/13 Oct/Nov 2014
88D19700/11 May/June 2015
89A19700/11 May/June 2015
90B19700/12 May/June 2015
91D19700/12 May/June 2015
92D19700/12 May/June 2015
93C19700/13 May/June 2015
94D19700/13 May/June 2015
95D19700/13 May/June 2015
96C19700/12 Oct/Nov 2015
97B19700/13 Oct/Nov 2015
98A19700/13 Oct/Nov 2015
99B19700/13 Oct/Nov 2015
100D19700/12 Feb/March 2016
101A19700/11 May/June 2016
102C19700/11 May/June 2016
103C19700/12 May/June 2016
104C19700/12 May/June 2016
105A19700/12 May/June 2016
106A19700/12 May/June 2016
107see sheet19700/13 May/June 2016
108C19700/11 Oct/Nov 2016
109D19700/13 Oct/Nov 2016
110A19700/13 Oct/Nov 2016
111C19700/13 Oct/Nov 2016
112D19700/12 Feb/March 2017
113C19700/12 Feb/March 2017
114D19700/12 Feb/March 2017
115B19700/12 Feb/March 2017
116C19700/11 May/June 2017
117B19700/11 May/June 2017
118C19700/12 May/June 2017
119D19700/12 May/June 2017
120D19700/13 May/June 2017
121A19700/13 May/June 2017
122C19700/12 Oct/Nov 2017
123A19700/12 Oct/Nov 2017
124B19700/12 Oct/Nov 2017
125D19700/13 Oct/Nov 2017
126A19700/13 Oct/Nov 2017
127B19700/13 Oct/Nov 2017
128A19700/12 Feb/March 2018
129A19700/12 Feb/March 2018
130B19700/12 Feb/March 2018
131A19700/11 May/June 2018
132A19700/11 May/June 2018
133D19700/11 May/June 2018
134A19700/11 May/June 2018
135C19700/12 May/June 2018
136B19700/12 May/June 2018
137C19700/12 May/June 2018
138D19700/13 May/June 2018
139A19700/13 May/June 2018
140D19700/11 Oct/Nov 2018
141D19700/11 Oct/Nov 2018
142A19700/11 Oct/Nov 2018
143A19700/12 Oct/Nov 2018
144D19700/12 Oct/Nov 2018
145D19700/12 Oct/Nov 2018
146B19700/13 Oct/Nov 2018
147A19700/13 Oct/Nov 2018
148B19700/12 Feb/March 2019
149A19700/12 Feb/March 2019
150B19700/11 May/June 2019
151A19700/12 May/June 2019
152B19700/12 May/June 2019
153B19700/12 May/June 2019
154A19700/13 May/June 2019
155D19700/13 May/June 2019
156C19700/11 Oct/Nov 2019
157B19700/12 Oct/Nov 2019
158B19700/12 Oct/Nov 2019
159D19700/12 Oct/Nov 2019
160C19700/13 Oct/Nov 2019
161B19700/13 Oct/Nov 2019
162C19700/12 Feb/March 2020
163A19700/11 May/June 2020
164A19700/11 May/June 2020
165A19700/11 May/June 2020
166B19700/12 May/June 2020
167D19700/13 May/June 2020
168A19700/13 May/June 2020
169B19700/13 May/June 2020
170D19700/13 May/June 2020
171D19700/11 Oct/Nov 2020
172A19700/11 Oct/Nov 2020
173D19700/11 Oct/Nov 2020
174C19700/13 Oct/Nov 2020
175D19700/13 Oct/Nov 2020
176C19700/13 Oct/Nov 2020
177C19700/12 Feb/March 2021
178B19700/11 May/June 2021
179D19700/11 May/June 2021
180C19700/11 May/June 2021
181D19700/11 May/June 2021
182B19700/12 May/June 2021
183C19700/13 May/June 2021
184B19700/13 May/June 2021
185D19700/13 May/June 2021
186C19700/11 Oct/Nov 2021
187C19700/11 Oct/Nov 2021
188C19700/12 Oct/Nov 2021
189C19700/12 Oct/Nov 2021
190A19700/12 Oct/Nov 2021
191see sheet19700/13 Oct/Nov 2021
192C19700/13 Oct/Nov 2021
193D19700/13 Oct/Nov 2021
194B19700/13 Oct/Nov 2021
195D19700/13 Oct/Nov 2021
196D19700/12 Feb/March 2022
197C19700/12 Feb/March 2022
198C19700/12 Feb/March 2022
199A19700/11 May/June 2022
200C19700/11 May/June 2022
201B19700/11 May/June 2022
202A19700/12 May/June 2022
203B19700/12 May/June 2022
204A19700/12 May/June 2022
205B19700/13 May/June 2022
206B19700/13 May/June 2022
207A19700/13 May/June 2022
208D19700/11 Oct/Nov 2022
209D19700/11 Oct/Nov 2022
210B19700/11 Oct/Nov 2022
211B19700/12 Oct/Nov 2022
212C19700/12 Oct/Nov 2022
213B19700/12 Oct/Nov 2022
214D19700/13 Oct/Nov 2022
215C19700/12 Feb/March 2023
216D19700/12 Feb/March 2023
217C19700/11 May/June 2023
218C19700/11 May/June 2023
219B19700/12 May/June 2023
220B19700/12 May/June 2023
221B19700/13 May/June 2023
222D19700/13 May/June 2023
223D19700/13 May/June 2023
224B19700/13 May/June 2023
225A19700/13 May/June 2023
226A19700/12 Oct/Nov 2023
227D19700/12 Oct/Nov 2023
228B19700/12 Feb/March 2024
229D19700/12 Feb/March 2024
230C19700/11 May/June 2024
231B19700/11 May/June 2024
232D19700/11 May/June 2024
233C19700/11 May/June 2024
234D19700/12 May/June 2024
235B19700/12 May/June 2024
236A19700/12 May/June 2024
237A19700/13 May/June 2024
238C19700/13 May/June 2024
239B19700/11 Oct/Nov 2024
240A19700/12 Oct/Nov 2024
241A19700/12 Oct/Nov 2024
242A19700/12 Oct/Nov 2024
243D19700/13 Oct/Nov 2024
244A19700/13 Oct/Nov 2024
245C19700/13 Oct/Nov 2024
246C19700/12 Feb/March 2025
247B19700/12 Feb/March 2025
248A19700/12 Feb/March 2025
249D19700/12 May/June 2025
250C19700/12 May/June 2025
251B19700/13 May/June 2025
252A19700/13 May/June 2025
253B19700/13 May/June 2025
254D19700/13 May/June 2025
255D19700/14 May/June 2025
256C19700/14 May/June 2025
257D19700/11 Oct/Nov 2025
258B19700/11 Oct/Nov 2025
259A19700/11 Oct/Nov 2025
260A19700/13 Oct/Nov 2025
261C19700/13 Oct/Nov 2025

Another paper, or another topic

Paper
Paper 1261 questionsPaper 2questions comingPaper 4questions comingPaper 5questions coming

All of Biological molecules →

Questions as text

Q1 · Which term describes the type of bonding responsible for stabilising the secondary… 9700/11 Oct/Nov 2004

12 Which term describes the type of bonding responsible for stabilising the secondary structure of a protein? A disulphide B hydrogen C hydrophobic D ionic

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2004

Q2 · How many different polypeptides, each consisting of r amino acids, can be made if the… 9700/11 Oct/Nov 2004

13 How many different polypeptides, each consisting of r amino acids, can be made if the number of different amino acids available is n ? n r r n n A B C n x r D r

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2004

Q3 · At which levels of protein structure do hydrophobic interactions occur? 9700/11 May/June 2006

10 At which levels of protein structure do hydrophobic interactions occur? A primary, secondary and tertiary B primary, secondary, tertiary and quaternary C tertiary and quaternary D quaternary only

1 marks

Answer: C

This question in 9700/11 May/June 2006

Q4 · The diagram shows a dipeptide 9700/11 May/June 2006

11 The diagram shows a dipeptide. Which bond is the peptide bond? A B C D R1 O R2 H O N C C N C C H H H H OH

1 marks

Answer: C

This question in 9700/11 May/June 2006

Q5 · Which statement is true for cellulose, but not true for protein? 9700/11 Oct/Nov 2006

6 Which statement is true for cellulose, but not true for protein? A It is found in cell surface membranes. B It is synthesised from identical sub-units. C It is used as an energy source. D It may be a structural component.

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2006

Q6 · Which level of protein structure maintains the globular shapes of enzymes? 9700/11 Oct/Nov 2006

8 Which level of protein structure maintains the globular shapes of enzymes? A primary B secondary C tertiary D quaternary

1 marks

Answer: C

This question in 9700/11 Oct/Nov 2006

Q7 · Which type of bond is involved in maintaining primary, secondary and tertiary structure… 9700/11 Oct/Nov 2006

9 Which type of bond is involved in maintaining primary, secondary and tertiary structure in protein molecules? level of structure primary secondary tertiary A disulphide ionic hydrogen B covalent peptide ionic C ionic disulphide covalent D peptide hydrogen disulphide

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2006

Q8 · What is the function of iron in the haemoglobin molecule? 9700/11 Oct/Nov 2006

10 What is the function of iron in the haemoglobin molecule? A It binds oxygen to the haemoglobin molecule. B It makes the haemoglobin more soluble in the red blood cell. C It stabilises the quaternary structure of the protein. D It undergoes reversible oxidation and reduction.

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2006

Q9 · When solutions of dilute sodium hydroxide and copper(II) sulphate (biuret test) were… 9700/11 Oct/Nov 2007

7 When solutions of dilute sodium hydroxide and copper(II) sulphate (biuret test) were added to an unknown substance, a purple colour was observed. This test indicates the presence of which bond in the unknown substance? A disulphide B hydrogen C ionic D peptide

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2007

Q10 · The diagram shows part of a macromolecule in the form of triple helices, lying side by… 9700/11 Oct/Nov 2007

8 The diagram shows part of a macromolecule in the form of triple helices, lying side by side with covalent cross links between them. What is the name of the molecule? A cellulose B collagen C glycogen D triglyceride

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2007

Q11 · The diagrams show four different molecules 9700/11 Oct/Nov 2007

12 The diagrams show four different molecules. P Q CH2OH CH2OH C O H O H H N C C H C C H OH OH H H HO OH C C H OH R S CH2OH O OH C O C H OH H CH2 C C OH H H HO H O C C N C C H OH H OH H Which shows the correct information about the molecule or molecules? contains a forms 1,6 glycosidic forms peptide bonds carboxyl group bonds in glycogen by condensation A P P P and Q B Q R P and R C R R R and Q D S P Q and S

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2007

Q12 · How is the shape of a polypeptide chain maintained when it is coiled into an α helix? 9700/11 May/June 2008

7 How is the shape of a polypeptide chain maintained when it is coiled into an α helix? A disulphide bonds B hydrogen bonds C hydrophobic interactions D ionic bonds

1 marks

Answer: B

This question in 9700/11 May/June 2008

Q13 · What will break an ionic bond between amino acids? 9700/11 May/June 2008

10 What will break an ionic bond between amino acids? A condensation B hydrolysis C low temperature D pH change

1 marks

Answer: D

This question in 9700/11 May/June 2008

Q14 · When hydrolysed, which molecules have products containing a carboxyl group? 9700/11 May/June 2008

11 When hydrolysed, which molecules have products containing a carboxyl group? 1 phospholipids 2 polysaccharides 3 proteins A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

1 marks

Answer: B

This question in 9700/11 May/June 2008

Q15 · Which substances contain carbon, hydrogen, oxygen and nitrogen? 9700/11 Oct/Nov 2008

7 Which substances contain carbon, hydrogen, oxygen and nitrogen? 1 amylopectin 2 collagen 3 deoxyribonucleic acid A 2 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: C

This question in 9700/11 Oct/Nov 2008

Q16 · A number of different types of bonds maintain the structure of proteins 9700/11 Oct/Nov 2008

9 A number of different types of bonds maintain the structure of proteins. These include disulphide, hydrogen and ionic bonds, as well as hydrophobic interactions. Some of these are stronger than others. Which are the strongest? A disulphide bonds B hydrogen bonds C hydrophobic interactions D ionic bonds

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2008

Q17 · Haemoglobin is a globular protein consisting of four polypeptide chains – 2 alpha chains… 9700/11 Oct/Nov 2008

10 Haemoglobin is a globular protein consisting of four polypeptide chains – 2 alpha chains and 2 beta chains. In normal individuals, in the DNA which codes for each beta chain, the sixth triplet has a code for glutamic acid. In individuals with sickle cell anaemia this base triplet changes and codes for valine. What aspect of the haemoglobin molecule does this mutation change? A the iron content B the primary structure C the quaternary structure D the secondary structure

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2008

Q18 · Which type of molecule contains disulphide bonds and which contains glycosidic bonds? 9700/11 Oct/Nov 2008

11 Which type of molecule contains disulphide bonds and which contains glycosidic bonds? disulphide bonds glycosidic bonds A glycoprotein polysaccharide B nucleic acid glycoprotein C polysaccharide nucleic acid D protein triglyceride

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2008

Q19 · Which combination of bond types correctly shows the weak and strong bonds that hold a… 9700/12 Oct/Nov 2009

7 Which combination of bond types correctly shows the weak and strong bonds that hold a molecule of protein in shape? types of bond hydrogen disulfide ionic A strong strong weak B strong weak strong C weak strong strong D weak strong weak

1 marks

Answer: D

This question in 9700/12 Oct/Nov 2009

Q20 · Which statement is true for cellulose, but not true for protein? 9700/12 Oct/Nov 2009

8 Which statement is true for cellulose, but not true for protein? A It is found in cell surface membranes. B It is synthesised from identical sub-units. C It is used as an energy source. D It may be a structural component.

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2009

Q21 · The diagram shows a tripeptide molecule 9700/12 Oct/Nov 2009

10 The diagram shows a tripeptide molecule. H H O H C C C OH H H NH 1 H O H H C C C C 2 O H H 3 NH H H H C C C 4 O H NH2 At which two points will hydrolysis occur to release three amino acids? A 1 and 2 B 1 and 3 C 2 and 3 D 2 and 4

1 marks

Answer: D

This question in 9700/12 Oct/Nov 2009

Q22 · HIV-1 protease is an enzyme produced by the HIV virus 9700/12 Oct/Nov 2009

12 HIV-1 protease is an enzyme produced by the HIV virus. Two identical chains of 99 amino acids form the enzyme. In each chain, amino acids 25, 26 and 27 in the sequence form part of the active site. Which orders of protein structure control the shape of the active site? A primary, secondary, tertiary and quaternary B primary, secondary and tertiary only C primary and quaternary only D quaternary only

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2009

Q23 · Which features of collagen result in it having high tensile strength? 9700/12 Oct/Nov 2009

13 Which features of collagen result in it having high tensile strength? 1 covalent bonds form between adjacent molecules 2 each three-stranded molecule is held together by hydrogen bonds 3 every third amino acid in the polypeptide is small 4 the primary structure is held together by peptide bonds A 1 and 2 B 1, 2 and 3 C 1, 3 and 4 D 2, 3 and 4

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2009

Q24 · Which feature of haemoglobin makes it a globular protein? 9700/11 May/June 2010

13 Which feature of haemoglobin makes it a globular protein? A It has four cross-linked polypeptide chains forming a quaternary structure. B It has hydrophobic groups on the inside and hydrophilic groups on the outside. C It has hydrophobic interactions and is insoluble in water. D It has polypeptide chains which are cross-linked to form sheets.

1 marks

Answer: B

This question in 9700/11 May/June 2010

Q25 · The enzyme lysozyme secreted from tear glands forms deposits on contact lenses 9700/11 May/June 2010

15 The enzyme lysozyme secreted from tear glands forms deposits on contact lenses. Which ingredient would be effective in a contact lens cleaner for removing these deposits? A ethanol B lysosomes C pH buffers D proteases

1 marks

Answer: D

This question in 9700/11 May/June 2010

Q26 · Which feature of haemoglobin makes it a globular protein? 9700/12 May/June 2010

3 Which feature of haemoglobin makes it a globular protein? A It has four cross-linked polypeptide chains forming a quaternary structure. B It has hydrophobic groups on the inside and hydrophilic groups on the outside. C It has hydrophobic interactions and is insoluble in water. D It has polypeptide chains which are cross-linked to form sheets.

1 marks

Answer: B

This question in 9700/12 May/June 2010

Q27 · The enzyme lysozyme secreted from tear glands forms deposits on contact lenses 9700/12 May/June 2010

25 The enzyme lysozyme secreted from tear glands forms deposits on contact lenses. Which ingredient would be effective in a contact lens cleaner for removing these deposits? A ethanol B lysosomes C pH buffers D proteases

1 marks

Answer: D

This question in 9700/12 May/June 2010

Q28 · The enzyme lysozyme secreted from tear glands forms deposits on contact lenses 9700/13 May/June 2010

1 The enzyme lysozyme secreted from tear glands forms deposits on contact lenses. Which ingredient would be effective in a contact lens cleaner for removing these deposits? A ethanol B lysosomes C pH buffers D proteases

1 marks

Answer: D

This question in 9700/13 May/June 2010

Q29 · Which feature of haemoglobin makes it a globular protein? 9700/13 May/June 2010

38 Which feature of haemoglobin makes it a globular protein? A It has four cross-linked polypeptide chains forming a quaternary structure. B It has hydrophobic groups on the inside and hydrophilic groups on the outside. C It has hydrophobic interactions and is insoluble in water. D It has polypeptide chains which are cross-linked to form sheets.

1 marks

Answer: B

This question in 9700/13 May/June 2010

Q30 · A peptide bond is formed between atoms of which two elements? 9700/12 Oct/Nov 2010

7 A peptide bond is formed between atoms of which two elements? A carbon and carbon B carbon and hydrogen C carbon and nitrogen D hydrogen and nitrogen

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2010

Q31 · Which features affect the tensile strength of collagen? 9700/12 Oct/Nov 2010

8 Which features affect the tensile strength of collagen? 1 the helical structure of collagen chains 2 the small R group of the amino acids in collagen 3 the insoluble nature of collagen 4 the covalent bonds between collagen molecules A 1, 2, 3 and 4 B 1 and 3 only C 1, 2 and 4 only D 2, 3 and 4 only

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2010

Q32 · An amino acid can be represented as H R O N C C H H OH where R represents a variable side… 9700/12 Oct/Nov 2010

9 An amino acid can be represented as H R O N C C H H OH where R represents a variable side chain. Which is not a possible side chain? A CH3 B CH2CH2SCH3 C CH2CONH2 D HOCH2CH(OH)CH2OH

1 marks

Answer: D

This question in 9700/12 Oct/Nov 2010

Q33 · Which set of statements correctly describes haemoglobin? 9700/11 May/June 2011

8 Which set of statements correctly describes haemoglobin? A four polypeptide iron ions can in each chain, at 50 % saturation, chains, each associate with hydrophobic R two oxygen containing a oxygen forming groups of amino molecules are prosthetic group oxyhaemoglobin acids point towards transported by the the centre of the molecule molecule B polypeptide chains each chain contains two identical alpha each chain can interact to produce a a prosthetic group of chains and two transport an oxygen globular chain amino acids identical beta chains molecule surrounding an iron ion C polypeptide chains an iron ion is quaternary structure each molecule can interact to produce present within each of two alpha chains transport a total of an almost spherical haem group and two beta chains four oxygen atoms molecule D polypeptide chains iron ions in the in each chain, each molecule can produce a loose molecule can bind hydrophobic R transport a total of helical shape, which reversibly with groups of amino eight oxygen atoms curls to form a oxygen acids surround the spherical molecule iron ion

1 marks

Answer: A

This question in 9700/11 May/June 2011

Q34 · Which rows show the chemical groups present in the biological molecules listed? 9700/11 May/June 2011

10 Which rows show the chemical groups present in the biological molecules listed? biological presence of carboxyl presence of two or more molecule (COOH) groups hydroxyl (OH) groups 1 amino acid yes no 2 β-glucose no yes 3 glycerol no no 4 fatty acid yes no A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

1 marks

Answer: B

This question in 9700/11 May/June 2011

Q35 · Which correctly matches the functional and structural features of cellulose, collagen… 9700/11 May/June 2011

11 Which correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride? structure molecule held function fibrous together by branched chains hydrogen bonds A cellulose support Jv Jv x triglyceride | energy source x x x B collagen strengthening Jv Jv x cellulose support v x v Cc collagen strengthening Jv Jv Jv glycogen storage x x v D glycogen storage x Jv Jv triglyceride | energy source x Jv x key /=true xX =false

1 marks

Answer: A

This question in 9700/11 May/June 2011

Q36 · Which levels of protein structure can determine the specificity of an enzyme? 9700/11 May/June 2011

13 Which levels of protein structure can determine the specificity of an enzyme? 1 primary 2 secondary 3 tertiary 4 quaternary A 1, 2, 3 and 4 B 1, 2 and 3 only C 1, 2 and 4 only D 3 and 4 only

1 marks

Answer: A

This question in 9700/11 May/June 2011

Q37 · At which levels of protein structure do ionic bonds occur? 9700/12 May/June 2011

8 At which levels of protein structure do ionic bonds occur? 1 secondary 2 tertiary 3 quaternary A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: C

This question in 9700/12 May/June 2011

Q38 · Myoglobin is a protein with a similar function to haemoglobin 9700/12 May/June 2011

9 Myoglobin is a protein with a similar function to haemoglobin. However, myoglobin does not have a quaternary structure. Why does myoglobin not have a quaternary structure? A Myoglobin does not contain a haem group. B Myoglobin does not contain any alpha helices. C Myoglobin has a fibrous rather than a globular structure. D Myoglobin has only one polypeptide chain.

1 marks

Answer: D

This question in 9700/12 May/June 2011

Q39 · The diagram shows the structure of the amino acid cysteine 9700/12 May/June 2011

10 The diagram shows the structure of the amino acid cysteine. H H H N H S C C C OH H H O When two of these amino acids join together what bond(s) are formed? A disulfide bonds only B disulfide and peptide bonds C hydrogen, disulfide and peptide bonds D peptide bonds only

1 marks

Answer: D

This question in 9700/12 May/June 2011

Q40 · Which rows show the chemical groups present in the biological molecules listed? 9700/13 May/June 2011

32 Which rows show the chemical groups present in the biological molecules listed? biological presence of carboxyl presence of two or more molecule (COOH) groups hydroxyl (OH) groups 1 amino acid yes no 2 β-glucose no yes 3 glycerol no no 4 fatty acid yes no A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

1 marks

Answer: B

This question in 9700/13 May/June 2011

Q41 · Which correctly matches the functional and structural features of cellulose, collagen… 9700/13 May/June 2011

35 Which correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride? structure molecule held function fibrous together by branched chains hydrogen bonds A cellulose support J Jv x triglyceride | energy source x x x B collagen strengthening Jv Jv x cellulose support Jv x J Cc collagen strengthening Jv Jv Jv glycogen storage x x v D glycogen storage x Jv Jv triglyceride | energy source x Jv x key /=true xX = false

1 marks

Answer: A

This question in 9700/13 May/June 2011

Q42 · Which set of statements correctly describes haemoglobin? 9700/13 May/June 2011

36 Which set of statements correctly describes haemoglobin? A four polypeptide iron ions can in each chain, at 50 % saturation, chains, each associate with hydrophobic R two oxygen containing a oxygen forming groups of amino molecules are prosthetic group oxyhaemoglobin acids point towards transported by the the centre of the molecule molecule B polypeptide chains each chain contains two identical alpha each chain can interact to produce a a prosthetic group of chains and two transport an oxygen globular chain amino acids identical beta chains molecule surrounding an iron ion C polypeptide chains an iron ion is quaternary structure each molecule can interact to produce present within each of two alpha chains transport a total of an almost spherical haem group and two beta chains four oxygen atoms molecule D polypeptide chains iron ions in the in each chain, each molecule can produce a loose molecule can bind hydrophobic R transport a total of helical shape, which reversibly with groups of amino eight oxygen atoms curls to form a oxygen acids surround the spherical molecule iron ion

1 marks

Answer: A

This question in 9700/13 May/June 2011

Q43 · Which is the strongest type of bonding found in proteins? 9700/11 Oct/Nov 2011

7 Which is the strongest type of bonding found in proteins? A disulfide bonds B hydrogen bonds C hydrophobic interactions D ionic bonds

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2011

Q44 · Which is the strongest type of bonding found in proteins? 9700/13 Oct/Nov 2011

20 Which is the strongest type of bonding found in proteins? A disulfide bonds B hydrogen bonds C hydrophobic interactions D ionic bonds

1 marks

Answer: A

This question in 9700/13 Oct/Nov 2011

Q45 · Which level of protein structure maintains the globular shapes of enzymes? 9700/11 May/June 2012

10 Which level of protein structure maintains the globular shapes of enzymes? A primary B secondary C tertiary D quaternary

1 marks

Answer: C

This question in 9700/11 May/June 2012

Q46 · Which substances contain carbon, hydrogen, oxygen and nitrogen? 9700/11 May/June 2012

11 Which substances contain carbon, hydrogen, oxygen and nitrogen? 1 collagen 2 amylopectin 3 deoxyribonucleic acid A 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: B

This question in 9700/11 May/June 2012

Q47 · Which molecules contain C=O bonds? 9700/12 May/June 2012

8 Which molecules contain C=O bonds? 1 amino acids 2 fatty acids 3 proteins A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 9700/12 May/June 2012

Q48 · Which substances contain carbon, hydrogen, oxygen and nitrogen? 9700/13 May/June 2012

15 Which substances contain carbon, hydrogen, oxygen and nitrogen? 1 collagen 2 amylopectin 3 deoxyribonucleic acid A 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: B

This question in 9700/13 May/June 2012

Q49 · Which level of protein structure maintains the globular shapes of enzymes? 9700/13 May/June 2012

17 Which level of protein structure maintains the globular shapes of enzymes? A primary B secondary C tertiary D quaternary

1 marks

Answer: C

This question in 9700/13 May/June 2012

Q50 · Which row is correct for each of the molecules? 9700/11 Oct/Nov 2012

8 Which row is correct for each of the molecules? β-glucose collagen haemoglobin sucrose A hexose sugar structural contains the formed by with a molecular function, found in elements carbon, releasing a formula C6H12O6 tendons and hydrogen, iron, molecule of water blood vessel nitrogen and in a hydrolysis walls sulfur reaction B repeating a molecule each non-protein composed of two monomer of the consists of three haem group monosaccharides polysaccharide, polypeptide contains a central linked by a cellulose chains, each iron ion glycosidic bond containing a prosthetic group C monomer of the molecules lie has two identical formed by 1,6 glycosidic parallel to each α chains and two condensation of branches of the other, with cross- identical β chains two identical polysaccharide, links and monosaccharides glycogen staggered ends in its ring D polypeptide has all four levels digestion yields structure, the chains interact to of protein glucose and hydroxyl group of produce a fibrous structure and at fructose in equal carbon atom 1 is protein least four types of proportions above the plane bond of the ring

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2012

Q51 · Which molecules contain C=O bonds? 9700/11 Oct/Nov 2012

12 Which molecules contain C=O bonds? 1 amino acids 2 fatty acids 3 glycerol A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2012

Q52 · Which molecules have a structural formula that contains C=O bonds? 9700/12 Oct/Nov 2012

9 Which molecules have a structural formula that contains C=O bonds? 1 glucose 2 glycerol 3 protein A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 only

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2012

Q53 · Haemoglobin consists of two α chains and two β chains 9700/12 Oct/Nov 2012

10 Haemoglobin consists of two α chains and two β chains. Approximately 5 % of all humans have one amino acid in the β chain different from normal. Which level(s) of protein structure could be changed in these humans? A primary only B primary and quaternary only C primary, secondary and tertiary only D quaternary only

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2012

Q54 · Which row shows the types of bond found at different levels of protein structures? 9700/12 Oct/Nov 2012

12 Which row shows the types of bond found at different levels of protein structures? bonds level of protein structure peptide | hydrogen | ionic | hydrostatic A primary J x x v B secondary Xx v v x Cc tertiary x v v v D quaternary v x v v key Jv = present X = absent

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2012

Q55 · What describes a globular protein that is not soluble in water? 9700/13 Oct/Nov 2012

11 What describes a globular protein that is not soluble in water? A having amino acids with hydrophilic R groups facing out B having amino acids with polar R groups facing out C having a central core of amino acids with hydrophobic R groups D having amino acids with hydrophobic R groups facing out

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2012

Q56 · Features of four proteins, W, X, Y and Z, are described below 9700/11 May/June 2013

12 Features of four proteins, W, X, Y and Z, are described below. W consists of two polypeptides held together by disulfide bonds X consists of three polypeptides tightly coiled together Y consists of four polypeptides each with a prosthetic group Z consists of four polypeptides held together by disulfide bonds Which row correctly identifies the named proteins? antibody collagen haemoglobin A W X Y B W Y X C Z X Y D Z Y X

1 marks

Answer: C

This question in 9700/11 May/June 2013

Q57 · The R groups (side chains) of amino acids can be hydrophobic, hydrophilic, acidic or basic 9700/12 May/June 2013

7 The R groups (side chains) of amino acids can be hydrophobic, hydrophilic, acidic or basic. The diagram shows four different amino acid R groups. COOH NH2 OH CH3 CH2 (CH2)4 CH2 Ala Asp Lys Ser Which row is correct for these amino acid R groups? hydrophobic hydrophilic acidic basic A Ala Ser Asp Lys B Ala Ser Lys Asp C Asp Lys Ser Ala D Asp Ser Lys Ala

1 marks

Answer: A

This question in 9700/12 May/June 2013

Q58 · Which molecules contain a carboxyl group? 9700/12 May/June 2013

11 Which molecules contain a carboxyl group? 1 amino acid 2 glycerol 3 saturated fatty acid 4 unsaturated fatty acid A 1 and 2 only B 3 and 4 only C 1, 3 and 4 only D 2, 3 and 4 only

1 marks

Answer: C

This question in 9700/12 May/June 2013

Q59 · The diameter of some atoms when they form bonds are given in the table 9700/12 May/June 2013

12 The diameter of some atoms when they form bonds are given in the table. single bond double bond atom / nm / nm H 0.060 – O 0.132 0.110 N 0.140 0.120 C 0.154 0.134 The approximate length of the amino acid shown below was estimated using the figures in the table. R O H N C C O H H H 0.7 nm What would be the approximate length of a dipeptide formed using this amino acid? A 0.9 nm B 1.2 nm C 1.4 nm D 1.7 nm

1 marks

Answer: B

This question in 9700/12 May/June 2013

Q60 · Two solutions, 1 and 2, one containing starch and sucrose, and the other containing… 9700/13 May/June 2013

7 Two solutions, 1 and 2, one containing starch and sucrose, and the other containing glucose and protein, were tested with a variety of reagents to confirm their identity. The table shows the conclusions from the results recorded for the various tests. Which row identifies the two solutions? boil with boil with add iodine Benedict’s add biuret Benedict’s solution solution after solution solution acid hydrolysis 1 2 1 2 1 2 1 2 key A + – + – – + – + + = biological molecule present B – + + – + – – + – = biological C + – – + + – – + molecule absent D – + + – + + + –

1 marks

Answer: C

This question in 9700/13 May/June 2013

Q61 · What occurs during protein denaturation by extremes of pH? 9700/13 May/June 2013

12 What occurs during protein denaturation by extremes of pH? 1 breakage of peptide bonds leading to loss of shape of active site 2 disruption of existing ionic bonds between amino acid R-groups 3 loss of α-helical regular arrangement of amino acids 4 loss of protein tertiary structure resulting in loss of function A 1, 2, 3 and 4 B 2, 3 and 4 only C 1 and 3 only D 2 and 4 only

1 marks

Answer: B

This question in 9700/13 May/June 2013

Q62 · Collagen is a macromolecule with three polypeptides lying closely side by side in the… 9700/11 Oct/Nov 2013

8 Collagen is a macromolecule with three polypeptides lying closely side by side in the form of a triple helix. Every third amino acid in each polypeptide has the shortest possible R-group or side chain (– H) to allow close packing of the polypeptides. Which is the amino acid? A glucose B glycerol C glycine D guanine

1 marks

Answer: C

This question in 9700/11 Oct/Nov 2013

Q63 · The diagrams show the structures of two amino acids, each of which has two amine (–NH2)… 9700/11 Oct/Nov 2013

9 The diagrams show the structures of two amino acids, each of which has two amine (–NH2) groups. 1 2 4 5 H2N CH COOH H2N CH COOH CH2 CH2 3 C CH2 O NH2 6 C O NH2 A peptide bond is formed between the two amino acids. Which groups form the peptide bond? A 1 and 4 B 1 and 5 C 2 and 6 D 3 and 5

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2013

Q64 · Each list, 1, 2 and 3, shows some substances found in animal tissues 9700/11 Oct/Nov 2013

10 Each list, 1, 2 and 3, shows some substances found in animal tissues. 1 glucose, cholesterol, triglycerides, water. 2 glycogen, antibodies, adenine, phospholipids. 3 haemoglobin, carbon dioxide, mRNA, monosaccharides. Which shows one or more substances that contain nitrogen atoms? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2013

Q65 · A student wrote down three statements about antibodies 9700/11 Oct/Nov 2013

38 A student wrote down three statements about antibodies. 1 Their structure depends on peptide, hydrogen and disulfide bonds. 2 They are protein molecules with both tertiary and quaternary structure. 3 Four polypeptides provide four antigen binding sites. Which statements are true? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2013

Q66 · The formation of glycosidic and peptide bonds is responsible for polymerisation in some… 9700/12 Oct/Nov 2013

8 The formation of glycosidic and peptide bonds is responsible for polymerisation in some biological molecules. Which bonds are found in which molecules? glycosidic peptide A glycerol glycoprotein B glycogen glycerol C glycogen glycoprotein D glycoprotein glycolipid

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2013

Q67 · The diagrams show the structures of two amino acids, each of which has more than one… 9700/12 Oct/Nov 2013

9 The diagrams show the structures of two amino acids, each of which has more than one amine (–NH2) group. 1 2 4 H2N CH COOH H2N CH COOH CH2 CH2 CH2 CH2 C 3 CH2 O NH2 NH 5 C HN NH2 A peptide bond is formed between the two amino acids. Which groups form the peptide bond? A 1 and 4 B 2 and 4 C 2 and 5 D 3 and 4

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2013

Q68 · Which explains why haemoglobin is able to carry oxygen? 9700/12 Oct/Nov 2013

10 Which explains why haemoglobin is able to carry oxygen? A It consists of four polypeptides. B It contains iron. C It has a quaternary structure. D It is a globular protein.

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2013

Q69 · The diagrams show the structures of two amino acids, each of which has more than one… 9700/13 Oct/Nov 2013

9 The diagrams show the structures of two amino acids, each of which has more than one amine (–NH2) group. 1 3 4 H2N CH COOH H2N CH COOH CH2 CH2 CH2 C 5 O NH2 CH2 NH 2 C HN NH2 A peptide bond is formed between the two amino acids. Which groups form the peptide bond? A 1 and 3 B 1 and 5 C 2 and 4 D 2 and 5

1 marks

Answer: A

This question in 9700/13 Oct/Nov 2013

Q70 · Which combination of bond types correctly shows the weak and strong bonds that hold a… 9700/13 Oct/Nov 2013

10 Which combination of bond types correctly shows the weak and strong bonds that hold a molecule of protein in shape? types of bond hydrogen disulfide ionic A strong strong weak B strong weak strong C weak strong strong D weak strong weak

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2013

Q71 · The diagram shows the structure of four amino acids in solution 9700/11 May/June 2014

10 The diagram shows the structure of four amino acids in solution. COO– COO– H C H3N+ CH2 CH2 CH2 CH2 C N+H3 N+H3 H H glycine lysine COO– O COO– CH3 C C CH2 C N+H3 O– N+H3 H H alanine aspartate Which of these four amino acids have an overall charge? A alanine and aspartate B alanine and glycine C aspartate and lysine D glycine and lysine

1 marks

Answer: C

This question in 9700/11 May/June 2014

Q72 · Which level of organisation of a haemoglobin molecule is coded by a DNA molecule? 9700/11 May/June 2014

11 Which level of organisation of a haemoglobin molecule is coded by a DNA molecule? A primary structure B secondary structure C tertiary structure D quaternary structure

1 marks

Answer: A

This question in 9700/11 May/June 2014

Q73 · Which molecule contains a glycosidic bond? 9700/12 May/June 2014

11 Which molecule contains a glycosidic bond? A B H H O OH HO CH2 C C H C O C R H O O N CH3 CH2 C C H H C O C R H O O N CH3 C C H H C O C R O N H H H C D H CH2OH N O N H O H C H C O CH2OH H O C C C C H N C C C C H C N H N O OH H O H OH CH2OH HO N C C N C C C C O H N H OH OH H H

1 marks

Answer: C

This question in 9700/12 May/June 2014

Q74 · The diagrams show the structures of two amino acids, each of which has two carboxylic… 9700/12 May/June 2014

12 The diagrams show the structures of two amino acids, each of which has two carboxylic acid (–COOH) groups. 1 3 4 H2N CH COOH H2N CH COOH CH2 CH2 COOH 2 CH2 COOH 5 A peptide bond is formed between the two amino acids. Which groups form the peptide bond? A 1 and 4 B 1 and 5 C 2 and 3 D 2 and 5

1 marks

Answer: A

This question in 9700/12 May/June 2014

Q75 · What is the correct sequence for the processes involved in the formation of an enzyme in… 9700/12 May/June 2014

21 What is the correct sequence for the processes involved in the formation of an enzyme in a cell? A transcription → condensation → translation → ionic bonding B translation → hydrogen bonding → transcription → condensation C transcription → translation → condensation → ionic bonding D translation → transcription → ionic bonding → hydrogen bonding

1 marks

Answer: C

This question in 9700/12 May/June 2014

Q76 · Which comparative statements concerning biological molecules are correct? 9700/13 May/June 2014

9 Which comparative statements concerning biological molecules are correct? 1 A collagen molecule is a fibrous protein that contains many amino acids with hydrophobic R-groups whereas a haemoglobin molecule is a globular protein with no amino acids with hydrophobic R-groups. 2 Sucrose hydrolysis results in glycosidic bond breakage and the production of equal proportions of fructose and α-glucose molecules, whereas cellulose hydrolysis results in only β-glucose molecules. 3 The glycosidic bonds of glycogen have been formed between two α-glucose molecules, whereas with amylopectin, the bonds have been formed between an α-glucose molecule and a β-glucose molecule. A 1 and 2 B 1 and 3 C 2 only D 3 only

1 marks

Answer: C

This question in 9700/13 May/June 2014

Q77 · The diagram represents an amino acid 9700/13 May/June 2014

11 The diagram represents an amino acid. H R O N C C H H OH R represents a variable side chain. Which is not a possible side chain? A CH3 B CH2CH2SCH3 C CH2CONH2 D HOCH2CH(OH)CH2OH

1 marks

Answer: D

This question in 9700/13 May/June 2014

Q78 · One type of antigen is formed by a reaction between two different molecules 9700/13 May/June 2014

16 One type of antigen is formed by a reaction between two different molecules. Apart from oxygen, which other elements are found in this antigen? A carbon and hydrogen only B hydrogen and nitrogen only C carbon, nitrogen and phosphorus D carbon, hydrogen, nitrogen and sulfur

1 marks

Answer: D

This question in 9700/13 May/June 2014

Q79 · The growth of crop plants is often limited by the availability of nitrogen in the soil 9700/13 May/June 2014

40 The growth of crop plants is often limited by the availability of nitrogen in the soil. The graph shows the results of an investigation into the yield of a crop plant, with increasing levels of nitrogen supplied. 7 6 5 yield of a crop plant 4 / tonnes per ha 3 2 1 0 0 40 80 120 160 nitrogen supplied / kg per ha Which of the following best explains the shape of this curve? protein synthesis DNA synthesis A increases no effect B no effect no effect C increases increases D no effect increases

1 marks

Answer: C

This question in 9700/13 May/June 2014

Q80 · Which correctly matches the functional and structural features of cellulose, collagen… 9700/11 Oct/Nov 2014

8 Which correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride? structure molecule held function fibrous together by branched chains hydrogen bonds A cellulose support J Jv x triglyceride | energy source x x x B collagen strengthening Jv Jv x cellulose support v x J Cc collagen strengthening Jv Jv Jv glycogen storage x x v D glycogen storage x Jv Jv triglyceride | energy source x Jv x key /=true xX = false

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2014

Q81 · The diagram shows the relationship between the levels of protein structure and bonds 9700/11 Oct/Nov 2014

9 The diagram shows the relationship between the levels of protein structure and bonds. 1 2 3 4 5 Which row is correct? 1 2 3 4 5 A primary peptide secondary ionic tertiary B secondary hydrogen tertiary peptide primary C tertiary ionic primary peptide quaternary D quaternary ionic tertiary ionic secondary

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2014

Q82 · Which of the bonds stabilising the tertiary structure of a protein would be least likely… 9700/12 Oct/Nov 2014

10 Which of the bonds stabilising the tertiary structure of a protein would be least likely to break when the temperature is increased above the optimum for the protein? A disulfide B hydrogen C hydrophobic D ionic

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2014

Q83 · The diagram shows the structure of four amino acids in solution 9700/12 Oct/Nov 2014

11 The diagram shows the structure of four amino acids in solution. COO– COO– H C H3N+ CH2 CH2 CH2 CH2 C NH3 + NH3 + H H glycine lysine COO– O COO– CH3 C C CH2 C NH3 + O– NH3 + H H alanine aspartate Which amino acids have no overall charge? A alanine and aspartate B alanine and glycine C aspartate and lysine D glycine and lysine

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2014

Q84 · Which words from the table correctly complete the paragraph about enzymes? 9700/12 Oct/Nov 2014

13 Which words from the table correctly complete the paragraph about enzymes? When the pH of an environment is decreased below an enzyme’s optimum pH, ……1…… bonds between adjacent ……2…… groups, holding the ……3…… structure, are disrupted. 1 2 3 A hydrogen and ionic R tertiary B hydrogen hydroxyl secondary C ionic and peptide R primary and tertiary D peptide amine primary

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2014

Q85 · The enzyme lactase is found in the membranes of epithelial cells lining the small… 9700/12 Oct/Nov 2014

18 The enzyme lactase is found in the membranes of epithelial cells lining the small intestine. The enzyme is formed by a single polypeptide that folds to give three regions. • an active site with the free amino group outside the cell • a short section inside the membrane • a short section inside the cell What type of amino acid would be found in each of the three regions? inside the inside the outside cell membrane cell A hydrophilic hydrophobic hydrophilic B hydrophilic hydrophobic hydrophobic C hydrophobic hydrophilic hydrophobic D hydrophobic hydrophobic hydrophilic

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2014

Q86 · Which of the following terms can be used to describe the secondary structure of a protein? 9700/13 Oct/Nov 2014

10 Which of the following terms can be used to describe the secondary structure of a protein? 1 dipeptide 2 specific order of amino acids 3 α-helix 4 fibrous structure 5 β-pleated sheet A 1, 3, 4 and 5 B 1, 2 and 4 C 2 and 4 only D 3 and 5 only

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2014

Q87 · Why is haemoglobin stated to have a quaternary structure? 9700/13 Oct/Nov 2014

11 Why is haemoglobin stated to have a quaternary structure? A It has four haem groups. B It has two or more polypeptide chains. C It is coiled into a precise shape. D It is held together by four types of bonds.

1 marks

Answer: B

This question in 9700/13 Oct/Nov 2014

Q88 · The diagrams show different types of bond found in biological molecules 9700/11 May/June 2015

8 The diagrams show different types of bond found in biological molecules. 1 2 3 O NH O CH2 S S CH2 C N H 4 5 NH2 + O– O C CH2 C C CH2 C C O O C O C Which combination of bonds could not be found in a protein with a tertiary structure? A 1, 2, 3 and 4 B 1, 2 and 4 only C 3 and 5 D 5 only

1 marks

Answer: D

This question in 9700/11 May/June 2015

Q89 · Which description is correct? 9700/11 May/June 2015

11 Which description is correct? A A collagen molecule has a high proportion of the amino acid glycine, which has a very small side chain. B A group of three collagen fibres forms a strong, insoluble coiled structure termed a triple helix. C Each of the collagen polypeptides in a collagen molecule has a regular spiral arrangement of many alpha helices. D Peptide bonds are present between amino acids of the same polypeptide and between the different polypeptides forming the collagen molecule.

1 marks

Answer: A

This question in 9700/11 May/June 2015

Q90 · Which type of bond holds together an α-helix or β-pleated sheet of a protein? 9700/12 May/June 2015

7 Which type of bond holds together an α-helix or β-pleated sheet of a protein? A disulfide B hydrogen C ionic D peptide

1 marks

Answer: B

This question in 9700/12 May/June 2015

Q91 · What describes only the quaternary structure of haemoglobin? 9700/12 May/June 2015

8 What describes only the quaternary structure of haemoglobin? 1 α-helix 2 a dipeptide 3 a globular structure 4 the specific order of amino acids 5 four polypeptide chains joined together A 1, 2 and 3 B 2, 4 and 5 C 1 and 4 D 5 only

1 marks

Answer: D

This question in 9700/12 May/June 2015

Q92 · In a ribosome, which bond holds together two adjacent amino acids? 9700/12 May/June 2015

21 In a ribosome, which bond holds together two adjacent amino acids? A disulfide B hydrogen C ionic D peptide

1 marks

Answer: D

This question in 9700/12 May/June 2015

Q93 · The diagram shows the three dimensional structure of collagen 9700/13 May/June 2015

8 The diagram shows the three dimensional structure of collagen. Which labelled part represents a molecule of collagen? C B D A

1 marks

Answer: C

This question in 9700/13 May/June 2015

Q94 · Which type of bond does not hold together the tertiary structure of a protein? 9700/13 May/June 2015

9 Which type of bond does not hold together the tertiary structure of a protein? A disulfide B hydrogen C hydrophobic interactions D peptide

1 marks

Answer: D

This question in 9700/13 May/June 2015

Q95 · The protein glutenin gives bread dough its elasticity 9700/13 May/June 2015

11 The protein glutenin gives bread dough its elasticity. The diagram represents a polypeptide of glutenin. tightly tightly coiled coiled region region loose spiral What describes the structure of glutenin? A quaternary structure because there are both globular and fibrous regions B quaternary structure because there are both spiral and tightly coiled regions C secondary structure because the loose spiral is an α-helix D tertiary structure because the different regions form a 3D shape

1 marks

Answer: D

This question in 9700/13 May/June 2015

Q96 · The diagrams show the amino acid serine 9700/12 Oct/Nov 2015

10 The diagrams show the amino acid serine. Which circled area is different in all other amino acids? A B H H H H N H N H HO C C C OH HO C C C OH O H H O H H C D H H H H N H N H HO C C C OH HO C C C OH O H H O H H

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2015

Q97 · The synthesis of biological molecules requires the formation of bonds 9700/13 Oct/Nov 2015

8 The synthesis of biological molecules requires the formation of bonds. Which row is correct? a bond forms between a β-1,4 bond forms the hydroxyl group of the carboxylic the phosphate of one between the monomers acid group is removed and a monomer and the sugar to give an unbranched carbon-nitrogen bond is formed to of the next monomer chain give an unbranched chain A polynucleotide amylose polypeptide B polynucleotide cellulose polypeptide C phospholipid amylose polynucleotide D phospholipid cellulose polynucleotide

1 marks

Answer: B

This question in 9700/13 Oct/Nov 2015

Q98 · High concentrations of urea break all bonds, except covalent bonds, in protein molecules 9700/13 Oct/Nov 2015

10 High concentrations of urea break all bonds, except covalent bonds, in protein molecules. Which level of protein structure would remain unchanged when a protein is treated with urea? A primary B secondary C tertiary D quaternary

1 marks

Answer: A

This question in 9700/13 Oct/Nov 2015

Q99 · Haemoglobin, a globular protein, consists of four polypeptide chains, two alpha chains… 9700/13 Oct/Nov 2015

11 Haemoglobin, a globular protein, consists of four polypeptide chains, two alpha chains and two beta chains. In normal individuals, in the DNA which codes for each beta chain, the sixth triplet has a code for glutamic acid. In individuals with sickle cell anaemia this base triplet mutates and codes for valine. What does this mutation change in the haemoglobin molecule? A the iron content B the primary structure C the quaternary structure D the secondary structure

1 marks

Answer: B

This question in 9700/13 Oct/Nov 2015

Q100 · When proteins are mixed with some organic solvents, hydrophobic interactions and hydrogen… 9700/12 Feb/March 2016

10 When proteins are mixed with some organic solvents, hydrophobic interactions and hydrogen bonding are changed in the protein molecules. Which levels of protein structure would be affected? 0 0O WwW D> level of protein structure secondary tertiary << x quaternary S44 key J = affected X = not affected

1 marks

Answer: D

This question in 9700/12 Feb/March 2016

Q101 · The diagrams show the structures of two amino acids, one of which has two amine (–NH2)… 9700/11 May/June 2016

10 The diagrams show the structures of two amino acids, one of which has two amine (–NH2) groups and the other has two carboxylic (–COOH) groups. 1 3 H2N CH COOH H2N CH COOH CH2 CH2 CH2 CH2 CH2 COOH 4 NH C 2 HN NH2 A peptide bond is formed between the two amino acids. Which groups form the peptide bond? A 1 and 3 B 2 and 3 C 2 and 4 D 4 and 1

1 marks

Answer: A

This question in 9700/11 May/June 2016

Q102 · Proteins which transport sugars out of cells have been identified 9700/11 May/June 2016

11 Proteins which transport sugars out of cells have been identified. These proteins are called SWEETs. Each SWEET has seven coiled, cylindrical regions which together make up a pore through the cell surface membrane bilayer, as shown in the diagram. 1 2 3 7 4 6 5 What describes each of the seven coiled regions (1-7) of a SWEET shown in the diagram? A primary structure held in its shape by bonds such as hydrogen bonds B primary structure held in its shape by peptide bonds C secondary structure held in its shape by bonds such as hydrogen bonds D secondary structure held in its shape by peptide bonds

1 marks

Answer: C

This question in 9700/11 May/June 2016

Q103 · Which biological molecules always contain the element nitrogen? 9700/12 May/June 2016

6 Which biological molecules always contain the element nitrogen? A amino acids, cellulose, mRNA B amino acids, DNA, lipids C enzymes, mRNA, tRNA D membrane proteins, starch, tRNA

1 marks

Answer: C

This question in 9700/12 May/June 2016

Q104 · Which statement about the quaternary structure of proteins is correct? 9700/12 May/June 2016

7 Which statement about the quaternary structure of proteins is correct? A consists of four subunits B depends on the presence of metal ions C depends on the primary structure of the subunits D is made of α and β subunits

1 marks

Answer: C

This question in 9700/12 May/June 2016

Q105 · Which set of statements correctly describes haemoglobin? 9700/12 May/June 2016

8 Which set of statements correctly describes haemoglobin? A in each chain, at 50 % saturation, four polypeptide iron ions can hydrophobic R two oxygen chains, each associate with groups of amino molecules are containing a haem oxygen forming acids point towards transported by the group oxyhaemoglobin the centre of the molecule molecule B each chain contains consists of two polypeptide chains a haem group of each chain can identical alpha interact to produce a amino acids transport an oxygen chains and two globular chain surrounding an iron molecule identical beta chains ion C polypeptide chains quaternary structure an iron ion is each molecule can interact to produce has two alpha present within each transport a total of an almost spherical chains and two beta haem group four oxygen atoms molecule chains D polypeptide chains in each chain, iron ions in the produce a loose hydrophobic R each molecule can molecule can bind helical shape, which groups of amino transport a total of reversibly with folds to form a acids surround the eight oxygen atoms oxygen spherical molecule iron ion

1 marks

Answer: A

This question in 9700/12 May/June 2016

Q106 · The diagrams show different types of bond found in biological molecules 9700/12 May/June 2016

9 The diagrams show different types of bond found in biological molecules. 1 2 3 O NH O C CH2 S S CH2 C N H 4 5 NH3 + O– O C C C CH2 C C CH2 C O C O O Which bonds are found in proteins with a tertiary structure? A 1, 2, 3 and 4 B 2, 3, 4 and 5 C 1 and 5 D 2 and 4 only

1 marks

Answer: A

This question in 9700/12 May/June 2016

Q107 · Which of the bonds will be last to break as the temperature of an enzyme is increased? 9700/13 May/June 2016

10 Which of the bonds will be last to break as the temperature of an enzyme is increased? A hydrogen B hydrophobic interactions C ionic D peptide

1 marks

This question in 9700/13 May/June 2016

Q108 · What could describe the tertiary structure of a protein? 9700/11 Oct/Nov 2016

11 What could describe the tertiary structure of a protein? 1 α-helix 2 a globular structure 3 the specific order of amino acids 4 a specific three-dimensional (3D) shape A 1, 2 and 3 B 1, 2 and 4 C 2 and 4 only D 3 and 4

1 marks

Answer: C

This question in 9700/11 Oct/Nov 2016

Q109 · Which row is correct for each of the molecules? 9700/13 Oct/Nov 2016

7 Which row is correct for each of the molecules? collagen haemoglobin sucrose A has a structural contains the formed by function, found in elements carbon, releasing a blood vessel hydrogen, iron, molecule of water walls nitrogen and in a hydrolysis sulfur reaction B molecules consist each non-protein composed of two of three haem group monosaccharides polypeptide contains a central linked by a chains, linked by iron ion glycosidic bond ionic bonds C molecules lie has two identical formed by parallel to each α chains and two condensation of other, with cross- identical β chains two identical links and monosaccharides staggered ends D polypeptide has all four levels digestion yields chains interact to of protein glucose and produce a fibrous structure and at fructose in equal protein least four types of proportions bond

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2016

Q110 · Threonylvaline is a dipeptide formed from the two amino acids, threonine and valine 9700/13 Oct/Nov 2016

9 Threonylvaline is a dipeptide formed from the two amino acids, threonine and valine. A peptide bond forms between the carboxyl group of threonine and the amine group of valine. The side-chains (R groups) of the two amino acids are shown. HO CH3 H3C CH3 CH CH threonine valine Which molecular structure is threonylvaline? A B HO CH3 H3C CH3 HO CH3 H3C CH3 CH O CH CH H CH H O H O N C C N C C N C C O N C C H H H H OH H H H H H OH C D H3C CH3 HO CH3 HO CH3 H3C CH3 CH O CH CH CH H O H O N C C N C C N C C N C C H H H H OH H O H H H OH

1 marks

Answer: A

This question in 9700/13 Oct/Nov 2016

Q111 · Which feature explains why haemoglobin is soluble? 9700/13 Oct/Nov 2016

10 Which feature explains why haemoglobin is soluble? A All four polypeptide chains are linked together to form a spherical molecule. B Each polypeptide chain folds due to interactions between hydrophobic R groups. C The hydrophilic R groups are arranged around the outside of the molecule. D The iron-containing haem group of each polypeptide chain is water soluble.

1 marks

Answer: C

This question in 9700/13 Oct/Nov 2016

Q112 · Some of the molecules found in animal tissues are grouped into three lists 9700/12 Feb/March 2017

10 Some of the molecules found in animal tissues are grouped into three lists. 1 glucose, cholesterol, triglycerides, water 2 glycogen, antibodies, adenine, phospholipids 3 haemoglobin, carbon dioxide, mRNA, monosaccharides Which lists include one or more molecules that always contain nitrogen atoms? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: D

This question in 9700/12 Feb/March 2017

Q113 · Haemoglobin consists of two α chains and two β chains 9700/12 Feb/March 2017

11 Haemoglobin consists of two α chains and two β chains. Approximately 5% of all humans have one amino acid in the β chain that has been changed, affecting the structure and stability of haemoglobin. Which of the levels of protein structure could be changed in the haemoglobin of these humans? A primary only B primary and quaternary only C primary, secondary, tertiary and quaternary D secondary, tertiary and quaternary only

1 marks

Answer: C

This question in 9700/12 Feb/March 2017

Q114 · Which row gives the correct description of both a collagen molecule and a collagen fibre? 9700/12 Feb/March 2017

12 Which row gives the correct description of both a collagen molecule and a collagen fibre? collagen molecule collagen fibre A α and β polypeptide chains molecules of collagen forming a double helix, held arranged randomly to each other, together by disulfide bonds linked by hydrogen bonds B a polypeptide chain, with repeating three molecules of collagen, amino acids, forming an α-helix forming a triple helix, held together by hydrogen bonds C a polypeptide chain, with three α helical collagen three repeating amino acids, molecules, forming a triple helix, forming a helix held together by ionic bonds D three helical polypeptide chains, molecules of collagen lying forming a triple helix, held parallel and cross-linked to each together by hydrogen bonds other

1 marks

Answer: D

This question in 9700/12 Feb/March 2017

Q115 · The diagrams show the structures of two amino acids, each of which has two amine (–NH2)… 9700/12 Feb/March 2017

13 The diagrams show the structures of two amino acids, each of which has two amine (–NH2) groups. 1 2 4 5 H2N CH COOH H2N CH COOH CH2 CH2 3 C CH2 O NH2 6 C O NH2 A peptide bond is formed between the two amino acids. Which groups could form the peptide bond? A 1 and 4 B 1 and 5 C 2 and 6 D 3 and 5

1 marks

Answer: B

This question in 9700/12 Feb/March 2017

Q116 · The diagram shows the molecular structure of a peptide 9700/11 May/June 2017

11 The diagram shows the molecular structure of a peptide. O NH2 C CH2 H O CH3 H H C N C C OH N C C N C H H H O CH2 H O OH Which molecules would result from the complete hydrolysis of the peptide? O NH2 C CH2 H CH2 H H H CH3 A N C COOH N C COOH N C COOH H H H H CH2 H O NH2 OH C H CH2 H H H CH3 B N C COOH N C COOH N C COOH H H H H H C OH H CH3 O NH2 C H CH2 H H H CH3 C N C COOH N C COOH N C COOH H H H H CH2 H NH2 OH O C H CH2 H H H H D N C COOH N C COOH N C COOH H H H H CH2 H OH

1 marks

Answer: C

This question in 9700/11 May/June 2017

Q117 · The diagram shows a haemoglobin molecule 9700/11 May/June 2017

12 The diagram shows a haemoglobin molecule. β-globin chain 3 α-globin chain 4 2 α-globin chain β-globin chain 1 Which row identifies the different parts of the molecule? 1 2 3 4 α-helix β-pleated binding site hydrophobic A sheet amino acids binding site hydrophilic α-helix hydrophobic B amino acids amino acids haem hydrophobic α-helix hydrophilic C group amino acids amino acids hydrophobic β-pleated haem binding site D amino acids sheet atom

1 marks

Answer: B

This question in 9700/11 May/June 2017

Q118 · Boiling the bones and teeth from dead animals can be used to produce a type of glue 9700/12 May/June 2017

5 Boiling the bones and teeth from dead animals can be used to produce a type of glue. The glue is formed from the collagen fibres present in bones and teeth. Which statement describes the changes to collagen that occur when the glue is produced? A The fibres of collagen become more coiled. B The fibres of collagen become more flexible. C The helices of collagen molecules unwind. D The molecules of collagen dissolve in water.

1 marks

Answer: C

This question in 9700/12 May/June 2017

Q119 · What describes the primary structure of a protein? 9700/12 May/June 2017

6 What describes the primary structure of a protein? A α-helix B a dipeptide C a globular structure D the specific order of amino acids

1 marks

Answer: D

This question in 9700/12 May/June 2017

Q120 · The diagram shows some of the relationships between cellulose, collagen and haemoglobin 9700/13 May/June 2017

7 The diagram shows some of the relationships between cellulose, collagen and haemoglobin. 1 2 3 4 5 Which row is correct? 1 2 3 4 5 A cellulose carbohydrate collagen protein haemoglobin B cellulose fibrous haemoglobin structural collagen C haemoglobin globular cellulose carbohydrate collagen D haemoglobin protein collagen structural cellulose

1 marks

Answer: D

This question in 9700/13 May/June 2017

Q121 · The diagram shows a protein molecule 9700/13 May/June 2017

8 The diagram shows a protein molecule. globular head key long polypeptide short polypeptide Two long polypeptides each form α-helices for much of their length and these twist together into a fibre. At one end, each of these polypeptides coils into a globular head. Two short polypeptides bind to each head. What describes the protein structure of this molecule? A quaternary structure because each molecule consists of six polypeptides B secondary structure because the long polypeptides form α-helices C tertiary structure because the α-helices form a fibre D tertiary structure because the heads form globular proteins

1 marks

Answer: A

This question in 9700/13 May/June 2017

Q122 · A student carried out four tests for biological molecules on a sample of milk 9700/12 Oct/Nov 2017

7 A student carried out four tests for biological molecules on a sample of milk. The tests and their results were as follows. ● Heating to 80 °C with Benedict’s solution gave a brick red colour. ● Adding Biuret solution gave a purple colour. ● Adding iodine solution gave an orange colour. ● Boiling with acid, followed by neutralisation, then heating to 80 °C with Benedict’s solution gave a brick red colour. Which biological molecules must be present in the milk? 1 non-reducing sugars 2 protein 3 reducing sugars 4 starch A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 and 4

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2017

Q123 · Which row correctly matches the functional and structural features of cellulose… 9700/12 Oct/Nov 2017

11 Which row correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride? structure molecules held molecule function fibrous together by branched chains hydrogen bonds A cellulose support Jv Jv x triglyceride energy source x x x B collagen strengthening Jv Jv x cellulose support Jv x Jv Cc collagen strengthening Jv Jv Jv glycogen storage x x Jv D glycogen storage x Jv Jv triglyceride | energy source x Jv x key J=true X = false

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2017

Q124 · A polypeptide has a number of amino acids (n) 9700/12 Oct/Nov 2017

12 A polypeptide has a number of amino acids (n). How many peptide bonds and R groups (side chains) does this polypeptide have? A n – 1 peptide bonds and n – 1 R groups B n – 1 peptide bonds and n R groups C n peptide bonds and n – 1 R groups D n peptide bonds and n R groups

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2017

Q125 · The diagram shows the amino acids in a polypeptide 9700/13 Oct/Nov 2017

9 The diagram shows the amino acids in a polypeptide. key type of amino acid polar basic polar acidic Asp Arg Lys polar Cys Thr Lys Leu non-polar Pro Asn Arg Val Ser Asn Glu Lys Thr Arg Phe Met Lys Phe Gln Met Ala His Val Gln Met Ala His Asn Asp Ala Glu Cys Thr Ser C terminal end Tyr Ser Glu Asn Lys Ser Thr Ser Ser N terminal end Ser Ala Ala An enzyme catalyses the hydrolysis of any peptide bond between a non-polar amino acid and any polar amino acid. How many small peptides and single amino acids will be formed by the action of this enzyme? small single peptides amino acids A 6 1 B 8 1 C 12 3 D 13 4

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2017

Q126 · A person with diabetes is unable to make enough of the protein insulin 9700/13 Oct/Nov 2017

10 A person with diabetes is unable to make enough of the protein insulin. Some forms of diabetes can be treated by using insulin produced by animals. Scientists have compared the amino acids in insulin produced by animals to human insulin. Which level of protein structure were the scientists studying? A primary B secondary C tertiary D quaternary

1 marks

Answer: A

This question in 9700/13 Oct/Nov 2017

Q127 · Which levels of protein structure are maintained by disulfide bonds? 9700/13 Oct/Nov 2017

12 Which levels of protein structure are maintained by disulfide bonds? A secondary, tertiary and quaternary B tertiary and quaternary only C quaternary only D tertiary only

1 marks

Answer: B

This question in 9700/13 Oct/Nov 2017

Q128 · Which diagram correctly shows the formation of a peptide bond between two amino acids? 9700/12 Feb/March 2018

9 Which diagram correctly shows the formation of a peptide bond between two amino acids? A B H H O H H O H H O N C C N C C N C C H2O H H C H OH H H OH H H OH H H O H C H H2O N C C C OH H H O OH C D H H O H H O N C C N C C H H C H OH H H C H OH H H O H H O C N C C C O OH N C C N O H H OH H H H2O H H OH H2O

1 marks

Answer: A

This question in 9700/12 Feb/March 2018

Q129 · Which molecules are globular proteins? 9700/12 Feb/March 2018

11 Which molecules are globular proteins? 1 amylase 2 haemoglobin 3 DNA polymerase A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 only

1 marks

Answer: A

This question in 9700/12 Feb/March 2018

Q130 · When hydrolysed, which molecules have products containing a carboxyl group? 9700/12 Feb/March 2018

12 When hydrolysed, which molecules have products containing a carboxyl group? 1 phospholipids 2 polysaccharides 3 proteins A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

1 marks

Answer: B

This question in 9700/12 Feb/March 2018

Q131 · The diagram shows relationships between some important molecules and bonds 9700/11 May/June 2018

7 The diagram shows relationships between some important molecules and bonds. 1 peptide glycosidic 3 ester 2 triglyceride cellulose vegetable oil amylopectin What is represented by circles numbered 1, 2 and 3? 1 2 3 A bonds formed carbohydrates lipids by condensation B bonds formed lipids carbohydrates by condensation C bonds formed carbohydrates lipids by hydrolysis D bonds formed lipids carbohydrates by hydrolysis

1 marks

Answer: A

This question in 9700/11 May/June 2018

Q132 · The diagrams show two arrangements of amino acids in a protein 9700/11 May/June 2018

10 The diagrams show two arrangements of amino acids in a protein. T S Which row correctly names the bonds at S or T? ionic bond hydrogen bond A absent S and T B S only T only C S and T absent D T only S and T

1 marks

Answer: A

This question in 9700/11 May/June 2018

Q133 · Students were asked to highlight only the R groups of two ring-shaped amino acids 9700/11 May/June 2018

11 Students were asked to highlight only the R groups of two ring-shaped amino acids. Which pair of diagrams are correct for both amino acids? H O H O H3N+ C C H2N+ C C A O– O– C NH H2C CH2 C CH2 C NH+ H O H O H3N+ C C H2N+ C C B O– O– C NH H2C CH2 C CH2 C NH+ H O H O H3N+ C C H2N+ C C C O– O– C NH H2C CH2 C CH2 C NH+ H O H O H3N+ C C H2N+ C C D O– O– C NH H2C CH2 C CH2 C NH+

1 marks

Answer: D

This question in 9700/11 May/June 2018

Q134 · Which words from the table correctly complete the paragraph about enzymes? 9700/11 May/June 2018

12 Which words from the table correctly complete the paragraph about enzymes? When the pH of an environment is decreased below the optimum pH of an enzyme, ««1«« bonds between adjacent ««2«« groups, holding the ««3«« structure, are disrupted. 1 2 3 A hydrogen and ionic R tertiary B hydrogen hydroxyl secondary C ionic and peptide R primary and tertiary D peptide amine primary

1 marks

Answer: A

This question in 9700/11 May/June 2018

Q135 · The diagram shows the relationship between some biological molecules 9700/12 May/June 2018

8 The diagram shows the relationship between some biological molecules. 1 2 3 4 5 Which row is correct? 1 2 3 4 5 A α-glucose carbohydrate sucrose monomer fructose B cellulose polymer starch carbohydrate amylase C fructose reducing sugar β-glucose monomer amino acid D haemoglobin protein amylose polymer cellulose

1 marks

Answer: C

This question in 9700/12 May/June 2018

Q136 · Which molecules contain C=O bonds? 9700/12 May/June 2018

10 Which molecules contain C=O bonds? 1 amino acids 2 fatty acids 3 glycerol A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 9700/12 May/June 2018

Q137 · Which row describes a collagen molecule? 9700/12 May/June 2018

11 Which row describes a collagen molecule? bonds stabilising properties primary structure helix the molecule A disulfide high temperatures high proportion double increase flexibility of glycine B disulfide resistant to repeat sequences single stretching of three amino acids C hydrogen high tensile repeat sequences triple strength of three amino acids D hydrogen insoluble high proportion alpha in water of glycine and proline

1 marks

Answer: C

This question in 9700/12 May/June 2018

Q138 · Which molecules contain the following bonds? 9700/13 May/June 2018

9 Which molecules contain the following bonds? ester hydrogen disulfide A amylase haemoglobin catalase B glycerol glycogen collagen C lipids amylopectin amylose D phospholipids cellulose antibodies

1 marks

Answer: D

This question in 9700/13 May/June 2018

Q139 · Which description is correct for collagen? 9700/13 May/June 2018

11 Which description is correct for collagen? A A collagen molecule has a high proportion of the amino acid glycine, which has a very small R group. B A group of three collagen fibres forms a strong, insoluble coiled structure termed a triple helix. C Each of the collagen polypeptides in a collagen molecule has a regular spiral arrangement of many alpha helices. D Peptide bonds are present between amino acids of the different polypeptides forming the collagen molecule.

1 marks

Answer: A

This question in 9700/13 May/June 2018

Q140 · Which statements about a peptide bond are correct? 9700/11 Oct/Nov 2018

11 Which statements about a peptide bond are correct? 1 It joins two monomers which are always identical to each other. 2 It contains four different atoms. 3 It can be broken by the addition of water at room temperature. 4 It is important in the primary structure of proteins. A 1, 2 and 3 B 1 and 3 only C 2, 3 and 4 D 2 and 4 only

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2018

Q141 · Which statements about the primary structure of a protein are correct? 9700/11 Oct/Nov 2018

12 Which statements about the primary structure of a protein are correct? 1 It may be branched. 2 It is determined by the sequence of DNA bases. 3 It is unique to that protein. 4 It determines the tertiary structure of the protein. A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2018

Q142 · The diagram shows a glycoprotein embedded in the cell surface membrane of a human red… 9700/11 Oct/Nov 2018

15 The diagram shows a glycoprotein embedded in the cell surface membrane of a human red blood cell. This glycoprotein is part of a system of cell surface blood group recognition sites. key = carbohydrate P cell surface membrane Q Which row identifies the role of this glycoprotein and regions P and Q of the molecule? role of region P region Q glycoprotein A antigen amino acids with amino acids with hydrophilic hydrophobic R groups R groups in the cell’s cytoplasm B carrier amino acids with amino acids with hydrophilic hydrophilic R groups R groups in the cell’s cytoplasm C channel amino acids with amino acids with hydrophobic hydrophilic R groups R groups outside the cell D receptor amino acids with amino acids with hydrophobic hydrophobic R groups R groups outside the cell

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2018

Q143 · Which diagram shows where a peptide bond would be formed? 9700/12 Oct/Nov 2018

10 Which diagram shows where a peptide bond would be formed? A B H R O H R O H R O O R H N C C N C C N C C C C N H H OH H H OH H H OH H O H H C D H R O H R O H R O H H N C C N C C N C C N H H OH H H OH H H OH H C R C O OH

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2018

Q144 · Which statements about collagen molecules are correct? 9700/12 Oct/Nov 2018

11 Which statements about collagen molecules are correct? 1 Both types of secondary structure occur within the molecules. 2 Large numbers of hydrogen bonds stabilise the molecules. 3 Repeated amino acid sequences determine the tertiary structure. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: D

This question in 9700/12 Oct/Nov 2018

Q145 · The protein glutenin gives bread dough its elasticity 9700/12 Oct/Nov 2018

12 The protein glutenin gives bread dough its elasticity. The diagram represents a polypeptide of glutenin. tightly tightly coiled coiled region region loose spiral What describes the structure of glutenin? A quaternary structure because there are both globular and fibrous regions B quaternary structure because there are both spiral and tightly coiled regions C secondary structure because the loose spiral is an α-helix D tertiary structure because the different regions form a 3D shape

1 marks

Answer: D

This question in 9700/12 Oct/Nov 2018

Q146 · The table shows the diameter of some atoms when they form bonds 9700/13 Oct/Nov 2018

12 The table shows the diameter of some atoms when they form bonds. single bond double bond atom / nm / nm H 0.060 – O 0.132 0.110 N 0.140 0.120 C 0.154 0.134 The approximate length of the amino acid shown was estimated using the figures in the table. R O H N C C O H H H 0.7 nm What would be the approximate length of a dipeptide formed using this amino acid? A 0.9 nm B 1.2 nm C 1.4 nm D 1.7 nm

1 marks

Answer: B

This question in 9700/13 Oct/Nov 2018

Q147 · Some animals produce antimicrobial proteins which protect them from pathogens 9700/13 Oct/Nov 2018

14 Some animals produce antimicrobial proteins which protect them from pathogens. These proteins could be used to kill human pathogens, however when used as a medicine they are broken down by protein-digesting enzymes. Replacing one of the amino acids found in the protein with one that had been synthesised in the laboratory resulted in a modified protein that was not broken down. What could explain why this modified protein was not broken down by the protein digesting enzymes? 1 The modified protein has a different tertiary structure to the original protein. 2 The modified protein is not complementary in shape to the enzyme’s active site. 3 The modified protein is unable to induce a fit with the protein digesting enzyme. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 2 only

1 marks

Answer: A

This question in 9700/13 Oct/Nov 2018

Q148 · The table compares three molecules, X, Y and Z, which contain the elements carbon… 9700/12 Feb/March 2019

11 The table compares three molecules, X, Y and Z, which contain the elements carbon, hydrogen and oxygen only. The percentage of carbon, hydrogen and oxygen atoms in each molecule is shown. molecule % carbon % hydrogen % oxygen X 25.0 50.0 25.0 Y 28.5 47.7 23.8 Z 34.6 61.6 3.8 Which row correctly identifies molecules X, Y and Z? molecule X Y Z A monosaccharide disaccharide polysaccharide B monosaccharide polysaccharide triglyceride C polysaccharide triglyceride monosaccharide D triglyceride monosaccharide polysaccharide

1 marks

Answer: B

This question in 9700/12 Feb/March 2019

Q149 · Which levels of protein structure can determine the specificity of an enzyme? 9700/12 Feb/March 2019

14 Which levels of protein structure can determine the specificity of an enzyme? 1 primary 2 secondary 3 tertiary 4 quaternary A 1, 2, 3 and 4 B 1, 2 and 3 only C 1, 2 and 4 only D 3 and 4 only

1 marks

Answer: A

This question in 9700/12 Feb/March 2019

Q150 · What is the minimum number of carbon atoms in an amino acid? 9700/11 May/June 2019

12 What is the minimum number of carbon atoms in an amino acid? A 1 B 2 C 3 D 4

1 marks

Answer: B

This question in 9700/11 May/June 2019

Q151 · Which diagram shows the formation of a peptide bond? 9700/12 May/June 2019

7 Which diagram shows the formation of a peptide bond? A B H H O H H O H H O O H H N C C N C C N C C C C N H H OH H H OH H H OH HO H H H2O H2O C D H H O H H O H H O O H H N C C N C C N C C C C N H H OH H H OH H H OH HO H H H2O H2O

1 marks

Answer: A

This question in 9700/12 May/June 2019

Q152 · In enzyme-catalysed reactions, the position of the amino acids found at the active site… 9700/12 May/June 2019

8 In enzyme-catalysed reactions, the position of the amino acids found at the active site is important. During the synthesis of enzymes, amino acids are brought together in the correct position to form the active site. Which levels of protein structure must be involved in forming the active site? level of protein structure primary | secondary tertiary quaternary v v v v key J = involved X = not involved 0 OO WwW PY x « & S44 x KOK \ <x

1 marks

Answer: B

This question in 9700/12 May/June 2019

Q153 · Which features affect the tensile strength of collagen? 9700/12 May/June 2019

9 Which features affect the tensile strength of collagen? 1 the helical structure of collagen chains 2 the small R group of the amino acids in collagen 3 the insoluble nature of collagen 4 the bonds between collagen molecules A 1, 2, 3 and 4 B 1, 2 and 4 only C 1 and 3 only D 2, 3 and 4 only

1 marks

Answer: B

This question in 9700/12 May/June 2019

Q154 · Which features of collagen result in it having high tensile strength? 9700/13 May/June 2019

13 Which features of collagen result in it having high tensile strength? 1 Bonds form between adjacent molecules. 2 Each three-stranded molecule is held together by hydrogen bonds. 3 Every third amino acid in the polypeptide is small. 4 The primary structure is held together by peptide bonds. A 1, 2 and 3 B 1, 3 and 4 C 1 and 2 only D 2, 3 and 4

1 marks

Answer: A

This question in 9700/13 May/June 2019

Q155 · Which levels of protein structure would always be changed if an enzyme works by the… 9700/13 May/June 2019

14 Which levels of protein structure would always be changed if an enzyme works by the induced fit hypothesis? primary secondary tertiary quaternary v v v v key ¥ = always changed 0 0O WwW D> v v x x Jv x X = not changed x x x < « x

1 marks

Answer: D

This question in 9700/13 May/June 2019

Q156 · Which statements could be used to describe enzyme molecules and antibody molecules? 9700/11 Oct/Nov 2019

12 Which statements could be used to describe enzyme molecules and antibody molecules? 1 Hydrogen bonds stabilise the structure of the protein and are important for it to function efficiently. 2 Hydrophilic R-groups point in to the centre of the molecule and cause it to curl into a spherical shape. 3 The tertiary structure of the protein molecule plays an important role in the functioning of the protein. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: C

This question in 9700/11 Oct/Nov 2019

Q157 · Which rows show the chemical groups present in the biological molecules listed? 9700/12 Oct/Nov 2019

9 Which rows show the chemical groups present in the biological molecules listed? biological presence of carboxyl presence of two or more molecule (COOH) groups hydroxyl (OH) groups 1 amino acid yes no 2 β-glucose no yes 3 glycerol no no 4 fatty acid yes no A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2019

Q158 · Fibrous proteins are composed of chains of amino acids held together by bonds 9700/12 Oct/Nov 2019

11 Fibrous proteins are composed of chains of amino acids held together by bonds. An example of part of a fibrous protein is shown. O R H N N H O X Y O R H N N H O Which type of bond is at X and Y? X Y A disulfide hydrophobic interaction B hydrogen peptide C hydrophobic interaction ionic D ionic peptide

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2019

Q159 · Which row about the structure of proteins is correct? 9700/12 Oct/Nov 2019

12 Which row about the structure of proteins is correct? primary structure secondary structure quaternary structure A is the number is the left-handed is the sub-unit of amino acids spiral formed by the polypeptides that present in a protein primary structure link together to form a protein B is the order of is the coiling of a contains two types amino acids present in chain of amino acids of polypeptide that a protein to form a β-pleated interact forming the encoded by DNA sheet or α-helix shape of a protein C is the result of occurs because of is formed by four translation of an attraction between polypeptides and mRNA molecule by hydrogen and an additional reactive a ribosome into a oxygen atoms in group attached to the chain of amino acids the peptide bonds protein D is the sequence is formed by is formed by the of amino acids in hydrogen bonding linking together a protein coded by between amino acids of more than one an mRNA molecule forming the polypeptide to primary structure form a protein

1 marks

Answer: D

This question in 9700/12 Oct/Nov 2019

Q160 · Three proteins that have a quaternary structure are listed 9700/13 Oct/Nov 2019

9 Three proteins that have a quaternary structure are listed. • Type IX collagen is formed from three different polymers. • The main form of haemoglobin contains two alpha globins and two beta globins. • HIV protease consists of two identical polymers. Which row shows the correct number of genes needed to code for each protein? number of genes type IX HIV haemoglobin collagen protease A 1 2 2 B 1 4 1 C 3 2 1 D 3 4 2

1 marks

Answer: C

This question in 9700/13 Oct/Nov 2019

Q161 · The diagrams show the structure of an amino acid with some parts of the molecule shaded 9700/13 Oct/Nov 2019

10 The diagrams show the structure of an amino acid with some parts of the molecule shaded. Which diagram shows the shaded part of the molecule that is common to all amino acids? A B H H C C NH2 NH2 CH3 CH3 COOH COOH C D H H C C NH2 NH2 CH3 CH3 COOH COOH

1 marks

Answer: B

This question in 9700/13 Oct/Nov 2019

Q162 · The diagrams show three examples of different bonds 9700/12 Feb/March 2020

11 The diagrams show three examples of different bonds. bond 1 bond 2 bond 3 O NH O C C N CH2 S S CH2 H Which bonds hold the secondary structure of proteins together? A 1, 2 and 3 B 1 and 2 only C 1 only D 2 and 3 only

1 marks

Answer: C

This question in 9700/12 Feb/March 2020

Q163 · Which molecules contain at least two double bonds? 9700/11 May/June 2020

9 Which molecules contain at least two double bonds? 1 unsaturated fatty acid 2 collagen 3 haemoglobin A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 9700/11 May/June 2020

Q164 · The diagram shows a protein molecule 9700/11 May/June 2020

10 The diagram shows a protein molecule. globular head key long polypeptide short polypeptide Two long polypeptides each form α-helices for much of their length and these twist together into a fibre. At one end, each of these polypeptides coils into a globular head. Two short polypeptides bind to each globular head. What describes the protein structure of this molecule? A quaternary structure because each molecule consists of six polypeptides B secondary structure because the long polypeptides form α-helices C tertiary structure because the α-helices form a fibre D tertiary structure because the heads form globular proteins

1 marks

Answer: A

This question in 9700/11 May/June 2020

Q165 · Which types of bond will keep a folded protein in its precise shape for the longest time… 9700/11 May/June 2020

11 Which types of bond will keep a folded protein in its precise shape for the longest time as the temperature rises? A disulfide B hydrogen C hydrophobic interactions D ionic

1 marks

Answer: A

This question in 9700/11 May/June 2020

Q166 · What occurs during the formation of a peptide bond between two amino acids? 9700/12 May/June 2020

11 What occurs during the formation of a peptide bond between two amino acids? A OH is removed from COOH and H is removed from an R group. B OH is removed from COOH and H is removed from NH2. C H is removed from COOH and OH is removed from an R group. D O is removed from COOH and 2H is removed from NH2.

1 marks

Answer: B

This question in 9700/12 May/June 2020

Q167 · The diagram shows a small part of a polypeptide 9700/13 May/June 2020

8 The diagram shows a small part of a polypeptide. CH3 CH3 H O CH H CH N C CH N C CH N C H H O CH CH3 O CH2 CH3 What would the products be if the part shown was completely hydrolysed? H O H O H O A H N C C H N C C H N C C H OH OH CH OH CH CH3 CH3 CH3 CH2 CH3 H H O H H O H H O B N C C N C C N C C H H H H H H CH H CH CH3 CH3 CH3 CH2 CH3 H O H O H O C N C C N C C N C C H H OH H OH H CH OH CH CH3 CH3 CH3 CH2 CH3 H H O H H O H H O D N C C N C C N C C H H OH H OH H CH OH CH CH3 CH3 CH3 CH2 CH3

1 marks

Answer: D

This question in 9700/13 May/June 2020

Q168 · The enzyme trypsin hydrolyses proteins to amino acids 9700/13 May/June 2020

9 The enzyme trypsin hydrolyses proteins to amino acids. Trypsin does not function when the pH is very low as its 3D shape would be changed. What explains this change in 3D shape? A Hydrogen ions attach themselves to negatively charged R groups. B Hydrogen ions disrupt disulfide bonds. C Hydrogen ions increase hydrogen bonding between amino acids. D Hydrogen ions reduce the affinity of hydrophilic R groups for water.

1 marks

Answer: A

This question in 9700/13 May/June 2020

Q169 · The flow chart shows some of the steps in the formation of collagen 9700/13 May/June 2020

10 The flow chart shows some of the steps in the formation of collagen. three polypeptide chains held together by X bonds triple helix held together by intermolecular bonds Y Z Which row correctly identifies X, Y and Z? X Y Z A disulfide fibres fibrils B hydrogen fibrils fibres C hydrogen microfibrils fibres D peptide and hydrogen fibres microfibrils

1 marks

Answer: B

This question in 9700/13 May/June 2020

Q170 · Which molecules contain at least two double bonds? 9700/13 May/June 2020

11 Which molecules contain at least two double bonds? 1 saturated fatty acid 2 collagen 3 haemoglobin A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: D

This question in 9700/13 May/June 2020

Q171 · Which molecules are formed by condensation which involves a carboxyl group? 9700/11 Oct/Nov 2020

9 Which molecules are formed by condensation which involves a carboxyl group? A amylopectin, collagen, triglyceride, sucrose B amylopectin, collagen, triglyceride C amylopectin, -globin, sucrose D collagen, -globin, triglyceride

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2020

Q172 · Which row correctly matches the function with the structural features of cellulose… 9700/11 Oct/Nov 2020

10 Which row correctly matches the function with the structural features of cellulose, collagen, glycogen or triglyceride? structure molecules held molecule function fibrous together by branched chains hydrogen bonds A cellulose support Jv Jv x triglyceride | energy source x x x B collagen strengthening Jv Jv x cellulose support Jv x v Cc collagen strengthening Jv Jv Jv glycogen storage x x Jv D glycogen storage x Jv Jv x Jv x triglyceride energy source key J/=correct X = not correct

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2020

Q173 · The diagram shows the amino acids in a polypeptide 9700/11 Oct/Nov 2020

11 The diagram shows the amino acids in a polypeptide. key type of amino acid polar basic polar acidic Asp Arg Lys polar Cys Thr Lys Leu non-polar Pro Asn Arg Val Ser Asn Glu Lys Thr Arg Phe Met Lys Phe Gln Met Ala His Val Gln Met Ala His Asn Asp Ala Glu Cys Thr Ser C terminal end Tyr Ser Glu Asn Lys Ser Thr Ser Ser N terminal end Ser Ala Ala An enzyme catalyses the hydrolysis of any peptide bond between a non-polar amino acid and any polar amino acid. How many small peptides and single amino acids will be formed by the action of this enzyme? small single peptides amino acids A 6 1 B 8 1 C 12 3 D 13 4

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2020

Q174 · A student carried out tests for biological molecules on the same sample of milk 9700/13 Oct/Nov 2020

7 A student carried out tests for biological molecules on the same sample of milk. The tests and their results were as follows. ● Heating to 80 C with Benedict’s solution gave a red colour. ● Boiling with acid, followed by neutralisation, then heating to 80 C with Benedict’s solution also gave a red colour. ● Adding Biuret solution gave a purple colour. ● Adding iodine solution gave a yellow colour. Which biological molecules must be present in the milk? 1 non-reducing sugars 2 protein 3 reducing sugars 4 starch A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 and 4

1 marks

Answer: C

This question in 9700/13 Oct/Nov 2020

Q175 · Adult human haemoglobin typically consists of two  chains and two  chains 9700/13 Oct/Nov 2020

12 Adult human haemoglobin typically consists of two  chains and two  chains. Approximately 5% of humans have one amino acid in the  chain that has been changed. This change affects the structure and stability of haemoglobin. Which levels of protein structure could be affected in the haemoglobin of the humans with the changed amino acid? A primary only B primary and quaternary only C secondary, tertiary and quaternary only D primary, secondary, tertiary and quaternary

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2020

Q176 · Lysozyme occurs in human tears, saliva, milk and mucus 9700/13 Oct/Nov 2020

13 Lysozyme occurs in human tears, saliva, milk and mucus. Lysozyme has a role in the immune system and hydrolyses peptidoglycan. Which description of lysozyme is correct? A It is an extracellular antibody. B It is an intracellular antibody. C It is an extracellular antibacterial protein. D It is an intracellular antibacterial protein.

1 marks

Answer: C

This question in 9700/13 Oct/Nov 2020

Q177 · Which statement about collagen is correct? 9700/12 Feb/March 2021

12 Which statement about collagen is correct? A Tissues containing collagen fibres cannot stretch. B Each polypeptide chain forms an alpha helix. C Three helices are held together by hydrogen bonds. D Three polypeptide chains form a single collagen fibre.

1 marks

Answer: C

This question in 9700/12 Feb/March 2021

Q178 · Which pair of molecules only includes macromolecules that can be found in animal cells? 9700/11 May/June 2021

8 Which pair of molecules only includes macromolecules that can be found in animal cells? A amylase and amylopectin B collagen and glycogen C deoxyribose and starch D sucrose and haemoglobin

1 marks

Answer: B

This question in 9700/11 May/June 2021

Q179 · Which description of collagen is correct? 9700/11 May/June 2021

11 Which description of collagen is correct? A A collagen molecule consists of three polypeptide chains, each in the shape of a helix. The three chains are wound together into a triple helix called a fibre. B A collagen molecule consists of three polypeptide chains, each of which is an -helix. The three chains are wound tightly together into a triple helix. Many of these triple helices bind together as a fibre. C A collagen molecule consists of three polypeptide chains wound tightly into a triple helix called a fibre. D A collagen molecule consists of three polypeptide chains in which every third amino acid is glycine. The three polypeptides are wound tightly together into a triple helix. Many of these helices form a fibre.

1 marks

Answer: D

This question in 9700/11 May/June 2021

Q180 · In a healthy human, the mean value for the number of haemoglobin molecules in one red… 9700/11 May/June 2021

12 In a healthy human, the mean value for the number of haemoglobin molecules in one red blood cell is 260 million. How many -globin chains does one red blood cell contain in a healthy human? A 1.3  108 B 2.6  108 C 5.2  108 D 1.04  109

1 marks

Answer: C

This question in 9700/11 May/June 2021

Q181 · Which statements about a peptide bond are correct? 9700/11 May/June 2021

13 Which statements about a peptide bond are correct? 1 It joins two monomers which are always identical to each other. 2 It contains four different atoms. 3 It can be broken by the addition of water at room temperature. 4 It is important in the primary structure of proteins. A 1, 2 and 3 B 1 and 3 only C 2, 3 and 4 D 2 and 4 only

1 marks

Answer: D

This question in 9700/11 May/June 2021

Q182 · Which molecule contains the smallest number of hydrogen atoms? 9700/12 May/June 2021

11 Which molecule contains the smallest number of hydrogen atoms? A -glucose B glycine, an amino acid in which the R group is H C glycerol D a saturated fatty acid containing eight carbon atoms

1 marks

Answer: B

This question in 9700/12 May/June 2021

Q183 · Which molecules contain at least three double bonds? 9700/13 May/June 2021

11 Which molecules contain at least three double bonds? A saturated fatty acid, collagen and haemoglobin B collagen and saturated fatty acid C haemoglobin and collagen D saturated fatty acid and haemoglobin

1 marks

Answer: C

This question in 9700/13 May/June 2021

Q184 · The diagrams show the structures of two amino acids 9700/13 May/June 2021

12 The diagrams show the structures of two amino acids. One contains two amino (–NH2) groups, labelled 1 and 2. The other contains two carboxylic (–COOH) groups, labelled 3 and 4. 2 3 H2N CH COOH H2N CH COOH CH2 CH2 C 1 COOH 4 O NH2 A peptide bond is formed between the two amino acids. Which groups form the peptide bond? A 1 and 4 B 2 and 3 C 2 and 4 D 1 and 3

1 marks

Answer: B

This question in 9700/13 May/June 2021

Q185 · Which row about the structure of proteins is correct? 9700/13 May/June 2021

13 Which row about the structure of proteins is correct? primary structure secondary structure tertiary structure quaternary structure A is the number is the right-handed is the result of is the sub-unit of amino acids spiral formed by the cross-bonding polypeptides that present in a protein primary structure between specific link together to amino acids in form a protein the primary structure B is the order of is the coiling of a is the shape formed contains two types amino acids present chain of amino acids by the folding of a of polypeptide that in a protein to form a -pleated polypeptide and is interact forming the encoded by DNA sheet or an -helix held together by shape of a protein hydrogen bonds C is the result of occurs because of an is the result of ionic is formed by four translation of an attraction between and hydrogen bonds, polypeptides and mRNA molecule by hydrogen and disulfide bridges an additional a ribosome into a oxygen atoms in and hydrophobic reactive group chain of amino acids the peptide bonds interactions between attached to the amino acids protein D is the sequence is formed by is formed as a result is formed by the of amino acids in hydrogen bonding of interaction of the linking together a protein coded by between amino acids side chains of of more than one an mRNA molecule forming the amino acids in the polypeptide to primary structure primary structure form a protein

1 marks

Answer: D

This question in 9700/13 May/June 2021

Q186 · The diagrams show three examples of different bonds 9700/11 Oct/Nov 2021

10 The diagrams show three examples of different bonds. bond 2 bond 1 bond 3 O NH O C C N CH2 S S CH2 H Which bonds hold the tertiary structure of proteins together? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: C

This question in 9700/11 Oct/Nov 2021

Q187 · Which feature of collagen enables it to fulfil a structural role in skin and in tendons? 9700/11 Oct/Nov 2021

11 Which feature of collagen enables it to fulfil a structural role in skin and in tendons? A Adjacent collagen molecules are linked by ester bonds. B Collagen fibres form layers with the fibres in different directions. C Collagen molecules are formed as a triple helix of polypeptide chains. D Polypeptide chains of collagen are tightly folded into compact shapes.

1 marks

Answer: C

This question in 9700/11 Oct/Nov 2021

Q188 · Which molecules contain at least two double bonds? 9700/12 Oct/Nov 2021

11 Which molecules contain at least two double bonds? A saturated fatty acid, collagen and haemoglobin B collagen and saturated fatty acid only C haemoglobin and collagen only D saturated fatty acid and haemoglobin only

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2021

Q189 · The diagram shows an amino acid 9700/12 Oct/Nov 2021

12 The diagram shows an amino acid. H CH3 O N C C H H OH Which group is changed to produce different amino acids? A OH B C=O C CH3 D NH2

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2021

Q190 · Which row is correct about the structure of proteins? 9700/12 Oct/Nov 2021

13 Which row is correct about the structure of proteins? primary secondary tertiary quaternary A determined by occurs by disulfide, ionic, always formed by the sequence of hydrogen bonding hydrogen bonds association of two DNA nucleotides between NH and and hydrophobic or more C=O groups of interactions are all polypeptides amino acids involved B the number of in a single the bonds are always formed by amino acids in polypeptide it is formed at specific two or more each polypeptide either an -helix points determined polypeptides held chain or a -pleated by the primary together by bonds sheet structure formed between the polypeptides C formed by an -helix is only globular always formed twenty different formed by proteins have this by two or amino acids hydrogen bonds level of structure more different linked in a between side polypeptides to specific order chains of give the final shape amino acids D the sequence a -pleated sheet reactions between always formed of amino acids in is the result of a side chains of by two or each polypeptide folded specific amino more polypeptides chain polypeptide acids give a and a metal ion forming hydrogen specific 3-D shape bonds between adjacent strands

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2021

Q191 · Which tests will identify biological molecules that contain monomers with a carboxyl… 9700/13 Oct/Nov 2021

7 Which tests will identify biological molecules that contain monomers with a carboxyl group? Benedict’s D A biuret ethanol C B

1 marks

This question in 9700/13 Oct/Nov 2021

Q192 · Which molecules always contain at least four double bonds? 9700/13 Oct/Nov 2021

10 Which molecules always contain at least four double bonds? A triglyceride, collagen and haemoglobin B collagen and triglyceride only C haemoglobin and collagen only D triglyceride and haemoglobin only

1 marks

Answer: C

This question in 9700/13 Oct/Nov 2021

Q193 · Which row about the structure of proteins is correct? 9700/13 Oct/Nov 2021

11 Which row about the structure of proteins is correct? primary structure secondary structure tertiary structure A the number the left-handed the result of of amino acids spiral formed by the cross-bonding between present in a protein primary structure specific amino acids in the primary structure B the order of the coiling of a the shape formed amino acids present chain of amino acids by folding of a in a protein to form a -pleated polypeptide and encoded by DNA sheet held together by hydrogen bonds C the result of occurs because of the result of ionic translation of an attraction between and hydrogen bonds, mRNA molecule by hydrogen and disulfide bridges a ribosome into a oxygen atoms in and hydrophobic chain of amino acids the side chains interactions between amino acids D the sequence formed by formed as a result of amino acids in hydrogen bonding of interaction of the a protein coded by between amino acids side chains of an mRNA molecule forming the amino acids in the primary structure primary structure

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2021

Q194 · Which statement about collagen is correct? 9700/13 Oct/Nov 2021

12 Which statement about collagen is correct? A A collagen fibre is made of three parallel helices with hydrogen bonds holding them in place. B It is an insoluble fibrous protein with a quaternary structure. C One-third of the amino acids making up collagen are valine. D Collagen fibres are formed from several collagen molecules held together by ionic bonds.

1 marks

Answer: B

This question in 9700/13 Oct/Nov 2021

Q195 · Which descriptions about all enzymes are correct? 9700/13 Oct/Nov 2021

14 Which descriptions about all enzymes are correct? 1 catalyse the breakdown of large molecules into smaller molecules 2 only function inside cells 3 form temporary bonds with the substrate 4 have a tertiary structure A 1 and 2 B 1 and 3 C 2 and 3 D 3 and 4

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2021

Q196 · Which row matches each molecule to a type of bond that is present? 9700/12 Feb/March 2022

9 Which row matches each molecule to a type of bond that is present? ester bond hydrogen bond disulfide bond A amylase haemoglobin catalase B glycerol glycogen collagen C lipid amylopectin amylose D phospholipid cellulose antibody

1 marks

Answer: D

This question in 9700/12 Feb/March 2022

Q197 · The diagrams show three examples of different bonds 9700/12 Feb/March 2022

14 The diagrams show three examples of different bonds. bond 2 bond 1 bond 3 O NH O C N CH2 S S CH2 H Which bonds can hold the quaternary structure of proteins together? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: C

This question in 9700/12 Feb/March 2022

Q198 · Which row correctly describes the primary structure, secondary structure, tertiary… 9700/12 Feb/March 2022

15 Which row correctly describes the primary structure, secondary structure, tertiary structure and quaternary structure of some proteins? primary secondary tertiary quaternary structure structure structure structure A determines the depends on defines the overall formed when two folding of the hydrogen bonding shape and folding or more identical polypeptide between the of the protein polypeptides join side-chains of together amino acids B defines the order usually forms is held together by found in globular of amino acids in immediately after all the types of proteins such as the polypeptide polypeptide bonding that haemoglobin but synthesis occur in proteins never in fibrous proteins C involves covalent involves essential for the formed when two bonds only interactions function of or more between –H and enzymes and polypeptides join =O receptors together D involves peptide involves folding changes can involve bonds between between local reversibly when hydrogen bonds, the side-chains of regions within a bound to covalent bonds amino acids polypeptide non-competitive and hydrophobic molecule inhibitors interactions

1 marks

Answer: C

This question in 9700/12 Feb/March 2022

Q199 · A polypeptide contains a specific number of amino acids, n 9700/11 May/June 2022

10 A polypeptide contains a specific number of amino acids, n. How many peptide bonds are present in this polypeptide? A n – 1 B n C n + 1 D n + 2

1 marks

Answer: A

This question in 9700/11 May/June 2022

Q200 · Which statement is correct? 9700/11 May/June 2022

11 Which statement is correct? A Amylase, ribose and phospholipid are all macromolecules. B Cellulose, glucose and catalase are all polymers. C Deoxyribose, fructose and ribose are all monosaccharides. D Sucrose, deoxyribose and amylopectin are all polysaccharides.

1 marks

Answer: C

This question in 9700/11 May/June 2022

Q201 · A student used colorimetry to monitor the hydrolysis of a protein by a protease enzyme 9700/11 May/June 2022

12 A student used colorimetry to monitor the hydrolysis of a protein by a protease enzyme. The student used biuret solution to determine the concentration of protein in the hydrolysis reaction. The student produced a calibration curve using known concentrations of protein. Which diagram shows the calibration curve? A B transmission absorbance 0 0 0 protein 0 protein concentration concentration C D transmission absorbance 0 0 0 protein 0 protein concentration concentration

1 marks

Answer: B

This question in 9700/11 May/June 2022

Q202 · Which statement is correct? 9700/12 May/June 2022

8 Which statement is correct? A Cellulose, glycogen and amylopectin are all polymers. B Ribose, amylase and phospholipid are all macromolecules. C Starch, glucose and amylose are all monomers. D Sucrose, deoxyribose and amylopectin are all polysaccharides.

1 marks

Answer: A

This question in 9700/12 May/June 2022

Q203 · The diagram shows two amino acids 9700/12 May/June 2022

9 The diagram shows two amino acids. Some of the hydrogen atoms are numbered 1 to 6. H H O H H O N C C N C C H H OH H H OH 1 2 3 4 5 6 Which two numbered hydrogen atoms could contribute to the production of a molecule of water when a peptide bond forms between these two amino acids? A 1 and 4 B 1 and 6 C 3 and 5 D 2 and 4

1 marks

Answer: B

This question in 9700/12 May/June 2022

Q204 · Typical enzymes are large globular proteins with a specific tertiary shape 9700/12 May/June 2022

11 Typical enzymes are large globular proteins with a specific tertiary shape. Which molecular interactions are directly involved in maintaining the tertiary shape? 1 hydrogen bonding 2 disulfide bridges 3 hydrophobic interactions A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 9700/12 May/June 2022

Q205 · Which molecule contains at least one peptide bond? 9700/13 May/June 2022

11 Which molecule contains at least one peptide bond? A B H H O OH HO CH2 C C H C O C R O H O O N HO C CH2 C C H H C O C R H O O N CH3 C C H H C O C R O N H H H C D HOCH2 NH2 CH2OH OH OH C N H O H C N H H H H HC H2 C CH OH H C N N HO O O CH2OH O O H OH –O HC CH P CH CH O O OH

1 marks

Answer: B

This question in 9700/13 May/June 2022

Q206 · RNA polymerase and peptidyl transferase are both enzymes involved in protein synthesis 9700/13 May/June 2022

12 RNA polymerase and peptidyl transferase are both enzymes involved in protein synthesis. Which statements describe similarities between these two enzymes? 1 They are both globular proteins. 2 They both have the same tertiary structure. 3 They are both intracellular enzymes. A 1 and 2 B 1 and 3 C 1 only D 2 and 3

1 marks

Answer: B

This question in 9700/13 May/June 2022

Q207 · The diagram shows a section of a glycoprotein molecule found embedded in a cell surface… 9700/13 May/June 2022

17 The diagram shows a section of a glycoprotein molecule found embedded in a cell surface membrane. Each of the amino acids is represented by a small shaded circle. amino acid Q amino acid chain forms an alpha helix Which row shows a property of the amino acids found in the alpha helix and a property of amino acid Q? property of property of amino acids found amino acid Q in the alpha helix A non-polar polar B non-polar non-polar C polar polar D polar non-polar

1 marks

Answer: A

This question in 9700/13 May/June 2022

Q208 · Which row correctly matches the example with the type of molecule? 9700/11 Oct/Nov 2022

8 Which row correctly matches the example with the type of molecule? disaccharide macromolecule monomer polymer A fructose glycogen glucose starch B starch haemoglobin ribose glycogen C maltose ribonucleic acid sucrose cellulose D sucrose cellulose fructose collagen

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2022

Q209 · Bread contains a mixture of polypeptides known as gluten 9700/11 Oct/Nov 2022

11 Bread contains a mixture of polypeptides known as gluten. Two of the polypeptides found in gluten are glutenin and gliadin. Which statement describes the tertiary structure of a protein? A Disulfide bonds form between glutenin and gliadin. B A large proportion of the amino acids in gliadin are glutamine. C α-helical sections are found in glutenin and gliadin. D Amino acids with hydrophobic R groups are found on the inside of glutenin.

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2022

Q210 · A shortage of protein in the diet of children can lead to a disease that causes excess… 9700/11 Oct/Nov 2022

34 A shortage of protein in the diet of children can lead to a disease that causes excess tissue fluid to build up in the abdomen. What explains why a build-up of excess tissue fluid can occur in this disease? A A shortage of plasma proteins decreases blood water potential; less tissue fluid returns to the blood. B A shortage of plasma proteins increases blood water potential; less tissue fluid returns to the blood. C A shortage of protein in the diet causes weak cardiac muscle, reducing hydrostatic pressure. D A shortage of protein in the tissue fluid decreases its water potential; more water leaves the blood.

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2022

Q211 · Silk moth caterpillars have been genetically modified to produce a mixture of their own… 9700/12 Oct/Nov 2022

11 Silk moth caterpillars have been genetically modified to produce a mixture of their own silk and the much stronger spider silk of the golden orb web spider. The spider silk polypeptide chain has many repeated sequences of two amino acids, glycine and alanine, arranged in a crystalline structure. What correctly describes the structure of spider silk? A primary protein structure with regions of α-helices B secondary protein structure with regions of β-pleated sheets C tertiary protein structure with regions of α-helices D quaternary protein structure with regions of β-pleated sheets

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2022

Q212 · Which property of the tertiary structure of a globular protein enables it to catalyse a… 9700/12 Oct/Nov 2022

12 Which property of the tertiary structure of a globular protein enables it to catalyse a metabolic reaction? A It has hydrophobic amino acid R groups on the outside. B It will be denatured by high temperatures. C The R groups of some amino acids form bonds with a substrate. D The three-dimensional shape depends on hydrogen bonding.

1 marks

Answer: C

This question in 9700/12 Oct/Nov 2022

Q213 · A student wrote three statements about antibodies 9700/12 Oct/Nov 2022

40 A student wrote three statements about antibodies. 1 Their structure depends on peptide, hydrogen and disulfide bonds. 2 They are protein molecules with both tertiary and quaternary structure. 3 Four polypeptides provide four antigen binding sites. Which statements are correct? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 9700/12 Oct/Nov 2022

Q214 · A scientist studying the structure of a protein reported that it consists of two… 9700/13 Oct/Nov 2022

11 A scientist studying the structure of a protein reported that it consists of two polypeptide chains joined by disulfide bonds. Which feature of protein structure does this describe? A primary structure B secondary structure C tertiary structure D quaternary structure

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2022

Q215 · Which row correctly shows levels of protein structure that can be held together by each… 9700/12 Feb/March 2023

11 Which row correctly shows levels of protein structure that can be held together by each type of interaction? hydrophobic hydrogen bonds covalent bonds interactions A primary, secondary tertiary structure primary and and tertiary structure tertiary structure B secondary structure primary and tertiary structure tertiary structure C secondary and tertiary structure primary and tertiary structure tertiary structure D secondary and tertiary structure primary and tertiary structure secondary structure

1 marks

Answer: C

This question in 9700/12 Feb/March 2023

Q216 · Which molecules contain at least three double bonds? 9700/12 Feb/March 2023

12 Which molecules contain at least three double bonds? saturated triglyceride C A D collagen B haemoglobin

1 marks

Answer: D

This question in 9700/12 Feb/March 2023

Q217 · The diagrams show three examples of different bonds 9700/11 May/June 2023

9 The diagrams show three examples of different bonds. bond 1 bond 2 bond 3 O NH O C C N CH2 S S CH2 H Which bonds hold the secondary structure of proteins together? A 1, 2 and 3 B 1 and 3 only C 1 only D 2 and 3 only

1 marks

Answer: C

This question in 9700/11 May/June 2023

Q218 · Insulin is a globular protein involved in cell signalling 9700/11 May/June 2023

10 Insulin is a globular protein involved in cell signalling. It is transported in the blood plasma from the cells that synthesise it to its target cells. A molecule of insulin contains six sulfur-containing amino acids and has two polypeptide chains. Which statements about insulin are correct? 1 An insulin molecule has a quaternary structure. 2 Insulin polypeptides are held together by six disulfide bonds. 3 Amino acids with hydrophobic R groups would be found in the centre of an insulin molecule. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: C

This question in 9700/11 May/June 2023

Q219 · Which molecules contain at least two double bonds? 9700/12 May/June 2023

9 Which molecules contain at least two double bonds? sucrose C A D collagen haemoglobin B

1 marks

Answer: B

This question in 9700/12 May/June 2023

Q220 · Which part of the structure of haemoglobin carries oxygen? 9700/12 May/June 2023

11 Which part of the structure of haemoglobin carries oxygen? A four polypeptide chains B haem groups C hydrogen bonds D hydrophilic R groups

1 marks

Answer: B

This question in 9700/12 May/June 2023

Q221 · Which polymers are present in all viruses, all prokaryotes and all eukaryotes? 9700/13 May/June 2023

5 Which polymers are present in all viruses, all prokaryotes and all eukaryotes? 1 polynucleotides 2 polypeptides 3 polysaccharides A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 9700/13 May/June 2023

Q222 · Which molecules contain at least four double bonds? 9700/13 May/June 2023

11 Which molecules contain at least four double bonds? unsaturated triglyceride C A D haemoglobin collagen B

1 marks

Answer: D

This question in 9700/13 May/June 2023

Q223 · The diagram shows the amino acid glutamic acid 9700/13 May/June 2023

12 The diagram shows the amino acid glutamic acid. COOH H C CH2 CH2 COOH NH2 What is the R group for glutamic acid? A NH2 B H C COOH D CH2 CH2 COOH

1 marks

Answer: D

This question in 9700/13 May/June 2023

Q224 · The diagram shows three interactions that hold protein molecules in shape 9700/13 May/June 2023

13 The diagram shows three interactions that hold protein molecules in shape. N H NH3 + O S S interaction 1 interaction 3 C COO– S S interaction 2 Which row identifies these interactions? interaction 1 interaction 2 interaction 3 A hydrogen bond disulfide bond hydrophobic interaction B hydrogen bond covalent bond ionic bond C hydrophobic interaction ionic bond hydrogen bond D ionic bond disulfide bond peptide bond

1 marks

Answer: B

This question in 9700/13 May/June 2023

Q225 · Some animals produce antimicrobial proteins which protect them from pathogens 9700/13 May/June 2023

14 Some animals produce antimicrobial proteins which protect them from pathogens. These proteins could be used to kill human pathogens, however when used as a medicine they are broken down by protein-digesting enzymes. Replacing one of the amino acids found in the protein with an amino acid that had been synthesised in the laboratory resulted in a modified protein that was not broken down. What could explain why this modified protein was not broken down by the protein-digesting enzymes? 1 The modified protein has a different tertiary structure to the original protein. 2 The modified protein is not complementary in shape to the enzyme’s active site. 3 The modified protein is unable to induce a fit with the protein-digesting enzyme. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 9700/13 May/June 2023

Q226 · Which bonds are present in all viruses? 9700/12 Oct/Nov 2023

7 Which bonds are present in all viruses? 1 phosphodiester 2 peptide 3 covalent A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2023

Q227 · The diagram represents an amino acid 9700/12 Oct/Nov 2023

11 The diagram represents an amino acid. H R O N C C H H OH R represents a variable side chain. What is not a possible side chain? A CH3 B CH2CH2SCH3 C CH2CONH2 D HOCH2CH(OH)CH2OH

1 marks

Answer: D

This question in 9700/12 Oct/Nov 2023

Q228 · Which molecules have a structural formula that contains C=O bonds? 9700/12 Feb/March 2024

9 Which molecules have a structural formula that contains C=O bonds? 1 amino acids 2 fatty acids 3 glycerol 4 protein A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

1 marks

Answer: B

This question in 9700/12 Feb/March 2024

Q229 · The diagram shows the structure of part of a peptidoglycan molecule 9700/12 Feb/March 2024

12 The diagram shows the structure of part of a peptidoglycan molecule. H CH2OH H O O H OH H H O H H O O O H CH2OH H3C CH C O NH HC CH3 CO NH HC (CH3)2COOH CO NH NH2 HC (CH3)2CHCOOH CO NH HC COOH CH3 Which type of 1,4 linkage and how many peptide bonds are shown in this part of the molecule? type of number of 1,4 linkage peptide bonds A α-1,4 3 B α-1,4 4 C β-1,4 3 D β-1,4 4

1 marks

Answer: D

This question in 9700/12 Feb/March 2024

Q230 · The diagrams show the structure of four amino acids in aqueous solution 9700/11 May/June 2024

6 The diagrams show the structure of four amino acids in aqueous solution. COO– COO– H C H3N+ CH2 CH2 CH2 CH2 C N+H3 N+H3 H H glycine lysine COO– O COO– CH3 C C CH2 C N+H3 O– N+H3 H H alanine aspartate Which two structures have an overall charge? A alanine and aspartate B alanine and glycine C aspartate and lysine D glycine and lysine

1 marks

Answer: C

This question in 9700/11 May/June 2024

Q231 · Collagen molecules are made up of three polypeptide chains interacting together 9700/11 May/June 2024

8 Collagen molecules are made up of three polypeptide chains interacting together. The individual polypeptide chains consist of a regular pattern of amino acids. Almost every third amino acid is glycine. Which protein structures of collagen are described? A primary and secondary B primary and quaternary C secondary and tertiary D tertiary and quaternary

1 marks

Answer: B

This question in 9700/11 May/June 2024

Q232 · The masses of the parts of haemoglobin are shown in the table 9700/11 May/June 2024

9 The masses of the parts of haemoglobin are shown in the table. component mass / Da -globin chain 15 126 -globin chain 15 868 haem group 15 617 There are 1000 Da in 1 kDa. What is the mass of a haemoglobin molecule in kDa? A 31.6 B 33.5 C 62.6 D 64.5

1 marks

Answer: D

This question in 9700/11 May/June 2024

Q233 · The diagram shows a simple metabolic pathway 9700/11 May/June 2024

14 The diagram shows a simple metabolic pathway. W  X  Y  Z The letters W, X, Y and Z represent four different substances. At each step in the diagram the substrate undergoes a chemical reaction catalysed by an enzyme. The reaction produces the next substance in the pathway. Which statements correctly describe the enzymes taking part in this metabolic pathway? 1 They are all globular proteins. 2 They all have the same tertiary structure. 3 They all contain hydrogen atoms in their structure. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 only

1 marks

Answer: C

This question in 9700/11 May/June 2024

Q234 · Which statements about peptide bond formation are correct? 9700/12 May/June 2024

7 Which statements about peptide bond formation are correct? 1 The bond formation occurs between a carbon of one amino acid and a nitrogen of the next amino acid after the amino acids detach from tRNA. 2 The bond formation occurs at the ribosome while the amino acids are still attached to tRNA, and is a hydrolysis reaction. 3 The bond formation is important for growth of an organism and when the bond forms, a water molecule is removed. A 1 and 3 B 2 and 3 C 2 only D 3 only

1 marks

Answer: D

This question in 9700/12 May/June 2024

Q235 · Which row correctly identifies the weak and strong bonds in the tertiary and quaternary… 9700/12 May/June 2024

12 Which row correctly identifies the weak and strong bonds in the tertiary and quaternary structure of a typical protein? type of bond disulfide hydrogen hydrophobic ionic A strong strong weak weak B strong weak weak weak C weak weak strong strong D weak weak weak strong

1 marks

Answer: B

This question in 9700/12 May/June 2024

Q236 · Which row correctly describes haemoglobin? 9700/12 May/June 2024

13 Which row correctly describes haemoglobin? A four polypeptide iron ions can in each chain, at 50% saturation, chains, each associate with hydrophobic R-groups two oxygen containing a oxygen, forming of amino acids point molecules are haem group oxyhaemoglobin towards the centre of transported by the the molecule molecule B polypeptide chains each chain consists of two each chain can interact to produce a contains a haem identical alpha chains transport an globular chain group of amino and two identical oxygen molecule acids surrounding beta chains an iron ion C polypeptide chains an iron ion is quaternary structure each molecule can interact to produce present within each has two alpha chains transport a total of an almost spherical haem group and two beta chains four oxygen atoms molecule D polypeptide chains iron ions in the in each chain, each molecule can produce a loose molecule can bind hydrophobic R-groups transport a total of helical shape, which reversibly with of amino acids eight oxygen atoms folds to form a oxygen surround the iron ion spherical molecule

1 marks

Answer: A

This question in 9700/12 May/June 2024

Q237 · What cannot occur as a result of a condensation reaction? 9700/13 May/June 2024

8 What cannot occur as a result of a condensation reaction? A breaking of a glycosidic bond B formation of a disaccharide C joining together of two amino acids D production of a molecule of water

1 marks

Answer: A

This question in 9700/13 May/June 2024

Q238 · Which fact about the quaternary structure of proteins is correct? 9700/13 May/June 2024

9 Which fact about the quaternary structure of proteins is correct? A consists of four polypeptides B depends on the presence of metal ions C depends on the primary structure of the polypeptides D is made of  and  polypeptides

1 marks

Answer: C

This question in 9700/13 May/June 2024

Q239 · The diagrams show parts of three pairs of amino acids within a protein 9700/11 Oct/Nov 2024

11 The diagrams show parts of three pairs of amino acids within a protein. The pairs are labelled X, Y and Z. X Y Z H H CH3 H3C O O C O O C C C C C H H H H H CH3 H3C H NH3 + –O Which row shows the correct type of interaction that would occur between the two amino acids in each pair? X Y Z A hydrophobic interaction hydrophobic interaction hydrogen bond B hydrogen bond hydrophobic interaction ionic bond C hydrogen bond hydrogen bond hydrogen bond D hydrophobic interaction hydrogen bond ionic bond

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2024

Q240 · The diagram shows part of a collagen fibril made of collagen triple helices 9700/12 Oct/Nov 2024

6 The diagram shows part of a collagen fibril made of collagen triple helices. The collagen triple helices are linked to each other by one type of bond. This bond is labelled as X in the diagram. X collagen fibril collagen triple helix What is bond X? A covalent bond B disulfide bond C hydrogen bond D peptide bond

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2024

Q241 · The table shows some information about the polypeptides that make up haemoglobin 9700/12 Oct/Nov 2024

7 The table shows some information about the polypeptides that make up haemoglobin. -globin -globin total number of amino acid 141 146 residues in polypeptide chain position of amino acid cysteine 104 93 and 112 in polypeptide chain Scientists studied the region of the -globin polypeptide chain containing the amino acid cysteine at position 93. They found that: ● this region faces outwards when no oxygen is attached to the haem group ● this region faces inwards when oxygen is attached to the haem group ● replacing cysteine with a different amino acid reduces the Bohr shift. What can be concluded from the information about cysteine in haemoglobin? A More than 1% of the amino acids in one haemoglobin protein are cysteine. B In -globin, there is a cysteine closer to the end of the polypeptide chain with an unreacted carboxyl group than in -globin. C The replacement of the cysteine at position 93 in -globin decreases the affinity of haemoglobin for oxygen at low pH. D The binding of oxygen to the haem group causes the region of -globin containing cysteine at position 93 to become more hydrophilic.

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2024

Q242 · Which molecules are globular proteins? 9700/12 Oct/Nov 2024

11 Which molecules are globular proteins? 1 amylase 2 haemoglobin 3 DNA polymerase A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 only

1 marks

Answer: A

This question in 9700/12 Oct/Nov 2024

Q243 · Which description lists all the components of a human haemoglobin molecule? 9700/13 Oct/Nov 2024

7 Which description lists all the components of a human haemoglobin molecule? A four polypeptides that are all the same and one haem group B four polypeptides that are not all the same and one haem group C four polypeptides that are all the same and four haem groups D four polypeptides that are not all the same and four haem groups

1 marks

Answer: D

This question in 9700/13 Oct/Nov 2024

Q244 · HIV-1 protease is an enzyme produced by the HIV virus 9700/13 Oct/Nov 2024

8 HIV-1 protease is an enzyme produced by the HIV virus. Two identical chains of 99 amino acids form the enzyme. In each chain, amino acids 25, 26 and 27 in the sequence form part of the active site. Which orders of protein structure control the shape of the active site? A primary, secondary, tertiary and quaternary B primary, secondary and tertiary only C primary and quaternary only D quaternary only

1 marks

Answer: A

This question in 9700/13 Oct/Nov 2024

Q245 · Which statements could be used to describe enzyme molecules and antibody molecules? 9700/13 Oct/Nov 2024

12 Which statements could be used to describe enzyme molecules and antibody molecules? 1 Hydrogen bonds stabilise the structure of the protein and are important for it to function efficiently. 2 Hydrophilic R-groups point in to the centre of the molecule and cause it to curl into a spherical shape. 3 The tertiary structure of the protein molecule plays an important role in the functioning of the protein. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: C

This question in 9700/13 Oct/Nov 2024

Q246 · Hydroxyproline is synthesised by addition of an –OH group to the R-group of the amino… 9700/12 Feb/March 2025

10 Hydroxyproline is synthesised by addition of an –OH group to the R-group of the amino acid proline. Hydroxyproline is a major component of collagen and has an important role in increasing the stability of its structure. Which statement explains why the addition of an –OH group to proline could increase the stability of collagen? A It strengthens hydrogen bonding between the R-groups of adjacent polypeptide chains, resulting in a tertiary structure that is more resistant to heat denaturation. B It increases the number of sites available for the formation of hydrogen bonds within the secondary structure of collagen, resulting in more stable alpha helices. C It increases the formation of hydrogen bonds between R-groups and water molecules, which help to hold the chains of the collagen triple helix together by strengthening hydrophilic interactions. D It strengthens the quaternary structure of collagen by providing more sites for hydrogen bonding between the R-groups of distantly separated amino acids within the same polypeptide chain.

1 marks

Answer: C

This question in 9700/12 Feb/March 2025

Q247 · Which levels of protein structure are always involved in forming the active site of an… 9700/12 Feb/March 2025

13 Which levels of protein structure are always involved in forming the active site of an enzyme? level of protein structure primary tertiary quaternary key v= always involved X = not always involved

1 marks

Answer: B

This question in 9700/12 Feb/March 2025

Q248 · The diagrams show three different bonds 9700/12 Feb/March 2025

38 The diagrams show three different bonds. 1 2 3 O H H N H O C N C S S C H H H Which bonds are found in an antibody molecule? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 9700/12 Feb/March 2025

Q249 · Which molecules contain at least two double bonds? 9700/12 May/June 2025

8 Which molecules contain at least two double bonds? saturated triglyceride C A D collagen haemoglobin B

1 marks

Answer: D

This question in 9700/12 May/June 2025

Q250 · Which bonds are found in the levels of structure of a protein molecule? 9700/12 May/June 2025

11 Which bonds are found in the levels of structure of a protein molecule? primary structure secondary structure quaternary structure A covalent bond hydrogen bond peptide bond B covalent bond ionic bond disulfide bond C peptide bond hydrogen bond ionic bond D peptide bond ionic bond disulfide bond

1 marks

Answer: C

This question in 9700/12 May/June 2025

Q251 · Which molecules have products containing a carboxyl group when they are hydrolysed? 9700/13 May/June 2025

11 Which molecules have products containing a carboxyl group when they are hydrolysed? 1 phospholipids 2 polysaccharides 3 proteins A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

1 marks

Answer: B

This question in 9700/13 May/June 2025

Q252 · Which bonds are involved in maintaining the secondary and tertiary levels of protein… 9700/13 May/June 2025

12 Which bonds are involved in maintaining the secondary and tertiary levels of protein structure? 1 disulfide 2 hydrogen 3 ionic secondary tertiary A 2 only 1, 2 and 3 B 2 and 3 only 2 and 3 only C 1 and 3 only 1 and 3 only D 1, 2 and 3 1 only

1 marks

Answer: A

This question in 9700/13 May/June 2025

Q253 · The diagrams show the structure of four amino acids in solution 9700/13 May/June 2025

13 The diagrams show the structure of four amino acids in solution. glycine lysine COO– COO– H C H3N+ CH2 CH2 CH2 CH2 C NH3 + NH3 + H H alanine aspartate COO– O COO– H3C C C CH2 C NH3 + O– NH3 + H H Which amino acids have no overall charge? A alanine and aspartate B alanine and glycine C aspartate and lysine D glycine and lysine

1 marks

Answer: B

This question in 9700/13 May/June 2025

Q254 · Histidine and proline are two amino acids commonly found in enzymes 9700/13 May/June 2025

15 Histidine and proline are two amino acids commonly found in enzymes. Histidine has a polar R-group and proline has a non-polar R-group. Where would most histidines and prolines be positioned? histidine proline A inside an enzyme on the surface of an enzyme B on the surface of an enzyme on the surface of an enzyme C inside an enzyme inside an enzyme D on the surface of an enzyme inside an enzyme

1 marks

Answer: D

This question in 9700/13 May/June 2025

Q255 · Which molecules contain at least two double bonds? 9700/14 May/June 2025

10 Which molecules contain at least two double bonds? unsaturated fatty acid C A D collagen haemoglobin B

1 marks

Answer: D

This question in 9700/14 May/June 2025

Q256 · Which description of globular proteins is correct? 9700/14 May/June 2025

11 Which description of globular proteins is correct? A They are only found in cell surface membranes. B They only contain amino acids with hydrophilic R groups. C They can change shape by using energy from ATP. D They always have a quaternary structure of at least three polypeptides.

1 marks

Answer: C

This question in 9700/14 May/June 2025

Q257 · Which diagram has a covalent bond that joins monomers together to form a biological… 9700/11 Oct/Nov 2025

8 Which diagram has a covalent bond that joins monomers together to form a biological polymer in eukaryotes? A B C D O R H O R O R R NH3 + –O C R C O R O R O P O R O–

1 marks

Answer: D

This question in 9700/11 Oct/Nov 2025

Q258 · Which molecules contain at least four double bonds? 9700/11 Oct/Nov 2025

10 Which molecules contain at least four double bonds? saturated triglyceride C A D collagen haemoglobin B

1 marks

Answer: B

This question in 9700/11 Oct/Nov 2025

Q259 · In some people a mutation can affect the beta chains in their haemoglobin molecules 9700/11 Oct/Nov 2025

11 In some people a mutation can affect the beta chains in their haemoglobin molecules. As a result polar amino acids on the outer surfaces of the chains are replaced by non-polar amino acids. What will be the effect on haemoglobin? A Haemoglobin will become less soluble. B Haemoglobin will become more soluble. C Hydrophobic interactions between amino acids will decrease. D More hydrogen bonds will form in the molecule.

1 marks

Answer: A

This question in 9700/11 Oct/Nov 2025

Q260 · Many biological molecules exist as polymers made up of monomer subunits 9700/13 Oct/Nov 2025

9 Many biological molecules exist as polymers made up of monomer subunits. Which row correctly identifies the monomer in each of the biological molecules? collagen glycogen cellulose A amino acid -glucose -glucose B -glucose -glucose amino acid C -glucose amino acid -glucose D amino acid -glucose -glucose

1 marks

Answer: A

This question in 9700/13 Oct/Nov 2025

Q261 · Which descriptions of enzymes that use the lock-and-key hypothesis are correct? 9700/13 Oct/Nov 2025

15 Which descriptions of enzymes that use the lock-and-key hypothesis are correct? 1 The active site is complementary to the substrate the enzyme acts on. 2 Bonds that form in the enzyme–substrate complex change the shape of the active site. 3 Most of the amino acids in an enzyme help to maintain the specific shape of the enzyme. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 3 only

1 marks

Answer: C

This question in 9700/13 Oct/Nov 2025