A-LevelBiologyEnzymesOct/Nov 2023Paper 1 Q141 Mark
Which statements about the Michaelis–Menten constant (Km) of an enzyme are correct? 1 At the Km value, half the active sites of the enzyme should be occupied by the substrate. 2 Km represents the substrate concentration at which the enzyme is working at half its maximum rate. 3 The lower the Km value, the lower the affinity of the enzyme to its substrate. 4 When an enzyme has a high Km value, the enzyme-catalysed reaction will proceed very slowly to its maximum rate.
A1, 2 and 3
B1, 2 and 4
C1 and 3 only
D2 and 4 only
✓ Correct Answer
The correct answer is B: 1, 2 and 4
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
🔒
Unlock the Examiner's Analysis
Sign up for free to reveal the full examiner report, trap analysis, and mark scheme breakdown for this question.
Sign Up Free to Unlock →Join thousands of Cambridge students already using Oracle Prep