Enzymes · CAPE Biology Unit 1

70 past-paper questions on Enzymes, part of Cell and Molecular Biology, from every CAPE Biology Unit 1 paper on Quelpr.

1. 1(a)6 marks· Biology · Unit 1 Q1 1(a)On the graph grid provided, plot a graph of the relative rates for BOTH salivary amylase and arginase.
2. 1(a)(i)3 marks· Biology · Unit 1 Q1 1(a)(i)On the grid in Figure 1, plot the data in Table 1 for the mammalian protease as a line graph.
3. 1(a)(ii)3 marks· Biology · Unit 1 Q1 1(a)(ii)Using arrows labelled P1 and P2, indicate, on the x-axis of Figure 1, the temperature at which EACH protease enzyme functions at its maximum efficiency. What accounts for any difference observed?
4. 1(a)(iii)3 marks· Biology · Unit 1 Q1 1(a)(iii)Enzymes are mainly globular proteins. With reference to the levels of protein organization, explain the effect of temperature on the prokaryote protease between 75 °C and 90 °C.
5. 1(b)(i)1 mark· Biology · Unit 1 Q1 1(b)(i)Using the graph, determine the optimal pH for arginase activity.
6. 1(b)(i)2 marks· Biology · Unit 1 Q1 1(b)(i)Enzymes have many properties. State ONE property of enzymes that relates to their structure and ONE property that relates to their MAIN function in the cell.
7. 1(b)(i)4 marks· Biology · Unit 1 Q1 1(b)(i)Complete the graph below to show the results given in Table 1.
8. 1(b)(ii)1 mark· Biology · Unit 1 Q1 1(b)(ii)Using the graph, determine the optimal pH for salivary amylase activity.
9. 1(b)(ii)2 marks· Biology · Unit 1 Q1 1(b)(ii)On the graph in Figure 2, sketch TWO curves to represent the progress of a reaction with and without the presence of an enzyme.
10. 1(b)(ii)2 marks· Biology · Unit 1 Q1 1(b)(ii)Suggest an explanation for the shape of the curve.
11. 1(b)(iii)2 marks· Biology · Unit 1 Q1 1(b)(iii)List TWO other variables that should be kept constant during this experiment.
12. 1(c)1 mark· Biology · Unit 1 Q1 1(c)Determine the optimal pH at which BOTH of these enzymes together digest compound X.
13. 1(c)3 marks· Biology · Unit 1 Q1 1(c)Outline an experiment to determine experimentally the presence of catalase in chick peas.
14. 1(c)(i)2 marks· Biology · Unit 1 Q1 1(c)(i)Describe the trend seen in EACH graph. Graph A: Graph B:
15. 1(c)(ii)4 marks· Biology · Unit 1 Q1 1(c)(ii)Suggest the type of inhibition represented by the data in EACH graph and state the reason for your answer. Graph A: Graph B:
16. 1(d)1 mark· Biology · Unit 1 Q1 1(d)Name TWO factors, in addition to pH, that can affect an enzyme's catalytic activity.
17. 4(a)7 marks· Biology · Unit 1 Q4 4(a)With reference to the structure of enzymes, distinguish between 'competitive inhibition' and 'non-competitive inhibition' with respect to enzyme activity.
18. 4(b)6 marks· Biology · Unit 1 Q4 4(b)Discuss the importance of protein structure for determining enzyme specificity and mode of action.
19. 4(b)6 marks· Biology · Unit 1 Q4 4(b)Enzymes are globular proteins and are highly specific in the reactions catalysed. Explain the basis of enzyme specificity and include in your explanation a brief description of the globular nature of these molecules.
20. 4(b)(i)2 marks· Biology · Unit 1 Q4 4(b)(i)Outline FOUR key stages in the mode of action of enzymes in catalysing chemical reactions.
21. 4(b)(ii)5 marks· Biology · Unit 1 Q4 4(b)(ii)Enzyme activity may be altered by poisons and drugs. Discuss, using a specific example, how poisons such as insecticides may affect enzyme activity.
22. 4(c)10 marks· Biology · Unit 1 Q4 4(c)Discuss the factors which affect enzyme activity.
23. 4(c)(i)8 marks· Biology · Unit 1 Q4 4(c)(i)Explain the mode of enzyme action according to the 'lock and key hypothesis'.
24. 4(c)(ii)8 marks· Biology · Unit 1 Q4 4(c)(ii)Comment on differences in the way in which competitive and non-competitive inhibitors affect enzyme activity.
25. 5(a)4 marks· Biology · Unit 1 Q5 5(a)With reference to the structure of enzymes, distinguish between competitive and non-competitive enzyme inhibition.
26. 5(a)(i)10 marks· Biology · Unit 1 Q5 5(a)(i)Using graphs and/or suitable examples, describe the effect of the following conditions on enzymes and enzymatic activity: Temperature.
27. 5(a)(ii)1 mark· Biology · Unit 1 Q5 5(a)(ii)Using graphs and/or suitable examples, describe the effect of the following conditions on enzymes and enzymatic activity: pH.
28. 5(a)(iii)1 mark· Biology · Unit 1 Q5 5(a)(iii)Using graphs and/or suitable examples, describe the effect of the following conditions on enzymes and enzymatic activity: Enzyme concentration and substrate concentration.
29. 5(b)6 marks· Biology · Unit 1 Q5 5(b)Describe the steps involved in an enzyme-catalysed reaction. In your description, make reference to the active site of an enzyme-substrate complex, lowering of the activation energy and enzyme specificity.
30. 5(b)6 marks· Biology · Unit 1 Q5 5(b)Discuss how the above named enzymes exhibit substrate or bond specificity and why they become inactive when boiled.
31. 5(c)4 marks· Biology · Unit 1 Q5 5(c)Discuss the regulation that is occurring in the metabolic pathway described.
32. 5(c)(i)2 marks· Biology · Unit 1 Q5 5(c)(i)Giving ONE reason, predict the effect that baking the bread over 110°C will have on enzyme activity.
33. 5(c)(ii)2 marks· Biology · Unit 1 Q5 5(c)(ii)Giving ONE reason, predict the effect that the addition of these bicarbonate ions will have on pepsin action as the stomach contents pass into the duodenum.
34. 5(c)(iii)2 marks· Biology · Unit 1 Q5 5(c)(iii)Giving ONE reason, predict the effect that the new weight of xylanase will have on the clarification process.
35. 5(c)(iv)2 marks· Biology · Unit 1 Q5 5(c)(iv)Giving ONE reason, predict the effect that this shortage will have on the clarification process.
36. 5(c)(v)2 marks· Biology · Unit 1 Q5 5(c)(v)Giving ONE reason, predict what would occur if xylanase were used to clarify fresh sugar cane juice.
37. Q141 mark · multiple choice· CAPE Biology Unit 1 · 2007 · Paper 1Which of the following pairs of statements explains the mode of action of enzymes? I. They are globular proteins and as a result are soluble. II. They bond to the substrate molecules at their active sites. III. They…
38. Q151 mark · multiple choice· CAPE Biology Unit 1 · 2007 · Paper 1The activation energy for an enzyme-catalysed reaction is represented by the region labelled
39. Q161 mark · multiple choice· CAPE Biology Unit 1 · 2007 · Paper 1The graph below shows the time course of the activity of the enzyme sucrase at various temperatures. At which of the following temperatures does the enzyme work at the FASTEST rate?
40. Q131 mark · multiple choice· CAPE Biology Unit 1 · 2007 (Specimen) · Paper 1Amylase found in germinating seeds is incubated with starch at 25^\circ\text{C} and pH 2. When a sample is removed after five minutes and mixed with a solution of iodine in potassium iodide solution, the mixture turns…
41. Q141 mark · multiple choice· CAPE Biology Unit 1 · 2007 (Specimen) · Paper 1Item 14 refers to the graph below which shows the rate of an enzyme catalysed reaction with and without inhibitors. Which of the following sequences describes the types of reaction shown by Graphs I, II and III?
42. Q151 mark · multiple choice· CAPE Biology Unit 1 · 2007 (Specimen) · Paper 1Which of the following graphs BEST illustrates the effect of temperature on an enzyme controlled reaction?
43. Q141 mark · multiple choice· CAPE Biology Unit 1 · 2008 (Rest of Region) · Paper 1Item 14 refers to the graph below showing the effect of pH on the activity of enzymes. Pepsin is an enzyme found in the human alimentary system. Which of the above activity curves represents the action of pepsin?
44. Q151 mark · multiple choice· CAPE Biology Unit 1 · 2008 (Rest of Region) · Paper 1Item 15 refers to the graph below which shows the relationship between enzyme concentration and the rate of an enzyme catalysed reaction. Based on the diagram above, which of the following statements BEST describes the…
45. Q131 mark · multiple choice· CAPE Biology Unit 1 · 2009 · Paper 1Chymotrypsin is an enzyme that is found in the human alimentary canal. It is active over a narrow range of alkaline pH values. Which of the activity curves represent the activity of chymotrypsin?
46. Q141 mark · multiple choice· CAPE Biology Unit 1 · 2009 · Paper 1Which of the labelled curves BEST represents the presence of a competitive inhibitor?
47. Q101 mark · multiple choice· CAPE Biology Unit 1 · 2010 · Paper 1Which of the following diagrams BEST illustrates the effect of temperature on the rate of an enzyme-catalysed reaction?
48. Q141 mark · multiple choice· CAPE Biology Unit 1 · 2010 · Paper 1Item 14 refers to the diagram below which represents the activation energy for an enzyme-catalysed reaction and an uncatalysed reaction. The activation energy for an enzyme-catalysed reaction is represented by the…
49. Q151 mark · multiple choice· CAPE Biology Unit 1 · 2010 · Paper 1Item 15 refers to the diagram below which shows the effect of increasing substrate concentration on the rate of an enzyme-catalysed reaction. Which of the labelled curves BEST represents the presence of a competitive…
50. Q151 mark · multiple choice· CAPE Biology Unit 1 · 2011 · Paper 1Item 15 refers to the diagram below which shows the effect of increasing substrate concentration on the rate of an enzyme-catalysed reaction. Which of the labelled curves BEST represents the presence of a competitive…
51. Q131 mark · multiple choice· CAPE Biology Unit 1 · 2012 · Paper 1Pepsin is an enzyme found in the human alimentary system. Which of the above activity curves represents the action of pepsin?
52. Q141 mark · multiple choice· CAPE Biology Unit 1 · 2012 · Paper 1Based on the diagram above, which of the following statements BEST describes the rate of the enzyme-catalysed reaction?
53. Q151 mark · multiple choice· CAPE Biology Unit 1 · 2012 · Paper 1Which of the labelled curves BEST represents the presence of a competitive inhibitor?
54. Q131 mark · multiple choice· CAPE Biology Unit 1 · 2013 · Paper 1Which of the following can be deduced from the information in the graph above?
55. Q131 mark · multiple choice· CAPE Biology Unit 1 · 2014 · Paper 1Which graph shows the changes in substrate concentration during the course of an enzyme-catalysed reaction?
56. Q141 mark · multiple choice· CAPE Biology Unit 1 · 2014 · Paper 1Which of the following graphs BEST shows the effect of pH on the reaction velocity of an enzyme?
57. Q151 mark · multiple choice· CAPE Biology Unit 1 · 2014 · Paper 1Item 15 refers to the graph below showing the rates of reaction of an enzyme with and without inhibitors. Which of the following describes the reaction represented by the curves, X, Y and Z? \begin{tabular}{|l|c|c|c|}…
58. Q141 mark · multiple choice· CAPE Biology Unit 1 · 2015 · Paper 1Pepsin is an enzyme found in the human alimentary system. Which of the above activity curves represents the action of pepsin?
59. 1(c)12 marks· CAPE Biology Unit 1 · May/June 2022 · Paper 2Explain the impact of the following factors on enzyme action using the information provided in Figure 2: pH, Temperature, Enzyme concentration, Substrate concentration.
60. 1(c)(i)2 marks· CAPE Biology Unit 1 · May/June 2023 · Paper 2State ONE responding and ONE manipulated variable in the experiment.
61. 1(c)(ii)1 mark· CAPE Biology Unit 1 · May/June 2023 · Paper 2Suggest ONE suitable control for the experiment.
62. 1(c)(iii)2 marks· CAPE Biology Unit 1 · May/June 2023 · Paper 2Outline your predicted results for the investigation.
63. 1(d)(i)2 marks· CAPE Biology Unit 1 · May/June 2023 · Paper 2Describe the induced fit hypothesis.
64. 1(d)(ii)12 marks· CAPE Biology Unit 1 · May/June 2023 · Paper 2With the aid of a diagram drawn in the space provided on page 9 using the provided symbols, explain how acetylcholinesterase is inhibited by organophosphates and atropine. Present your response in complete paragraphs.
65. 1(a)(i)2 marks· CAPE Biology Unit 1 · May/June 2025 · Paper 2Define the term 'activation energy'.
66. 1(a)(iii)5 marks· CAPE Biology Unit 1 · May/June 2025 · Paper 2Outline a suitable procedure to investigate the activity of amylase on a suspension of starch at 10 °C, 20 °C, 30 °C and 40 °C, including all relevant materials and apparatus and KI/I solution.
67. 1(a)(iv)2 marks· CAPE Biology Unit 1 · May/June 2025 · Paper 2Calculate the rate of reaction of the enzyme based on the graph shown in Figure 1.
68. 1(b)(i)1 mark· CAPE Biology Unit 1 · May/June 2025 · Paper 2State ONE reason why curve Y is MOST likely showing enzyme activity that is inhibited.
69. 1(b)(ii)4 marks· CAPE Biology Unit 1 · May/June 2025 · Paper 2Describe the action of EACH of the following inhibitors: - Organophosphate - Antabuse
70. 1(b)(iii)3 marks· CAPE Biology Unit 1 · May/June 2025 · Paper 2Explain whether the type of inhibition shown in Figure 2 on page 8 is competitive or non-competitive.