Enzymes: past paper questions
Real questions on enzymes
The newest 20 of 89 written questions, plus 52 multiple-choice. Open one to see it on the real paper.
- 5090/21 · October/November 2025 · Q3a(i)[2]
State the name of enzyme A and enzyme B. enzyme A (i)
See it on the paper → - 5090/22 · October/November 2025 · Q4a[2]
All enzymes are biological catalysts. Explain what is meant by the term catalyst.
See it on the paper → - 5090/22 · October/November 2025 · Q4c(i)[3]
Using Fig. 4.1, discuss the results from this investigation.
See it on the paper → - 5090/22 · October/November 2025 · Q4c(ii)[3]
The lipase molecules produced by different species of bacteria have different chemical structures. Explain: • • what determines the different chemical structures of lipase molecules why having different chemical structures can affect their activity at different temperatures.
See it on the paper → - 5090/21 · May/June 2025 · Q1c[3]
Explain how the sequence of bases in a DNA molecule controls how a cell functions.
See it on the paper → - 5090/21 · May/June 2025 · Q8a[6]
Explain how the features of the fermenter shown in Fig. 8.1 provide suitable conditions for the growth of fungi.
See it on the paper → - 5090/21 · May/June 2025 · Q8b[4]
In an experiment, scientists added pectinase made by the fungi to a sample of crushed fruit. They measured changes in: • • the sugar content of the sample of crushed fruit the thickness of the sample of crushed fruit. The scientists’ results are shown in Fig. 8.2. Key thickness sugar content sugar content thickness 0 5...
See it on the paper → - 5090/22 · May/June 2025 · Q5b(i)[4]
Explain the results for the pH range 2–7.
See it on the paper → - 5090/22 · May/June 2025 · Q5b(ii)[1]
The experiment was repeated at a temperature of 55 °C. On Fig. 5.1, draw a graph to suggest the results expected at 55 °C.
See it on the paper → - 5090/22 · May/June 2025 · Q5b(iii)[1]
Name an industrial process that uses pectinase.
See it on the paper → - 5090/22 · May/June 2025 · Q6b[4]
Explain how this DNA molecule controls cell function. Include an example in your answer.
See it on the paper → - 5090/21 · October/November 2024 · Q2a[4]
Complete Table 2.1, which provides descriptions of words related to the activity of maltase. The first row has been completed for you. word how it relates to the activity of maltase maltase an enzyme that is found in vertebrate intestines Table 2.1 the substrate of maltase part of the maltase molecule which fits the su...
See it on the paper → - 5090/21 · October/November 2024 · Q2b[2]
Vampire bats live in South America and feed entirely on blood. They are the only known vertebrates which do not have maltase in their intestines. Suggest an explanation for this.
See it on the paper → - 5090/21 · October/November 2024 · Q5b(iii)[1]
The ants feed on the oil bodies and digest the oil. Name the products of this digestion.
See it on the paper → - 5090/22 · October/November 2024 · Q5c[5]
Fish are a good source of lipids in the form of fish oil. A student investigated the digestion of fish oil in the laboratory. pH meter pH meter 8.0 8.0 experiment test-tube contents The student set up the two experiments shown in Fig. 5.2. 1 2 fish oil + bile solution fish oil + bile solution + lipase solution Fig. 5.2...
See it on the paper → - 5090/21 · May/June 2024 · Q5a(i)[4]
Two of the parts labelled A, B, C and D in Fig. 5.1 are involved in the manufacture of proteins such as lipase. Identify the two parts, name them and explain their role in protein manufacture. letter name role letter name role
See it on the paper → - 5090/21 · May/June 2024 · Q5c[3]
Lipase is also produced by the human body. Explain why it is produced and how its function is different from the function of bile.
See it on the paper → - 5090/22 · May/June 2024 · Q5b(i)[2]
When bromelain is added to its substrate, a product is formed. Complete the word equation to show the substrate and product. (product) (substrate)
See it on the paper → - 5090/22 · May/June 2024 · Q5b(ii)[4]
The effect of changing pH on the activity of the enzymes found in bromelain was investigated. The results of this investigation are shown in Fig. 5.2. 100 80 percentage of maximum enzyme activity 60 40 20 0 3 4 5 6 7 8 9 10 11 12 pH Fig. 5.2 To assist digestion, some people swallow bromelain in the form of a powder wit...
See it on the paper → - 5090/22 · October/November 2023 · Q2b(iii)[2]
Use your knowledge of how cell function is controlled to suggest why other animals are not able to digest lichenan.
See it on the paper →
What examiners said
This proved to be the least accessible part of this question. Candidates were most likely to realise that other animals could not digest lichenan because they lacked the appropriate enzyme. The next step was to state that this must mean that they lack the gene that codes for the enzyme but it was rare to see candidates linking these two ideas. Careful reading of the question was required to ensure...
— Examiner report, October/November 2023, 5090/22 Q2(b)(iii) (Cambridge)
Although most candidates attempted this question only a minority were able to recall that an enzyme involved in fruit juice production is pectinase. Other suggestions included protease, lipase, amylase, hydrochloric acid, catalyst and penicillin.
— Examiner report, October/November 2023, 5090/22 Q5(a)(i) (Cambridge)
Candidates were more familiar with this part of the question and the majority were able to state that beaker C was set up as a control or to allow a comparison to be made with the other beakers that contained the enzyme. If the words ‘control’ and ‘comparison’ were not used then the candidate needed to provide a very clear reason for setting up C. Statements such as ‘to measure and record the volu...
— Examiner report, October/November 2023, 5090/22 Q5(a)(ii) (Cambridge)
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