0654.B5.1.02 — Describe and explain enzyme action with reference to: the active site, enzyme–substrate complex, substrate and product: past paper questions
Real questions on 0654.b5.1.02 — describe and explain enzyme action with reference to: the active site, enzyme–substrate complex, substrate and product
The newest 7 of 7 written questions. Open one to see it on the real paper.
- 0654/43 · May/June 2025 · Q4b[3]
Germinating seeds contain an enzyme called amylase. Explain why seeds need amylase to grow.
See it on the paper → - 0654/43 · May/June 2025 · Q4c(i)[2]
β-amylase is active over a wider range of pH than α-amylase. Outline other differences between the activity of α-amylase and β-amylase at different pH values as shown in Fig. 4.2.
See it on the paper → - 0654/43 · May/June 2025 · Q4c(ii)[2]
Explain the activity of α-amylase at pH 9.
See it on the paper → - 0654/43 · May/June 2025 · Q4c(iii)[1]
Suggest why β-amylase needs to be active over a wider range of pH than α-amylase.
See it on the paper → - 0654/32 · February/March 2025 · Q3a(i)[3]
Complete the sentences using words from the list. Each word may be used once, more than once or not at all. chromosomes cilia secretes codes targets ribosomes walls Proteins are made in the cell by structures called . A gene is a length of DNA that for a protein.
See it on the paper → - 0654/11 · October/November 2019 · Q12[1]
Which is correct?
See it on the paper → - 0654/42 · May/June 2019 · Q1a(i)[1]
State the optimum temperature of the enzyme in Fig. 1.1.
See it on the paper →
What examiners said
Candidates found this very demanding. Many knew that starch was broken down but very few knew what was formed from the breakdown or thought amino acids were formed. Many thought that amylase contained starch or that starch was broken down to make energy which is needed for photosynthesis. A small number discussed respiration.
— Examiner report, May/June 2025, 0654/43 Q4(b) (Cambridge)
Most described at least one difference. Non-creditworthy responses discussed speed of changes, an enzyme staying constant, alpha showing a greater increase in activity, alpha being more consistent, alpha staying constant for longer and some simply repeated the information in the question.
— Examiner report, May/June 2025, 0654/43 Q4(c)(i) (Cambridge)
Denaturing of the enzyme was quite well known but few explained what the term meant. Common non-creditworthy responses included no activity because it is neutralised and that the pH is too high for the enzyme to be active.
— Examiner report, May/June 2025, 0654/43 Q4(c)(ii) (Cambridge)
Past papers, syllabus and examiner reports © UCLES (Cambridge University Press & Assessment). Questions are matched to topics from the official syllabus. AssessPro is independent and not endorsed by Cambridge.