The fatty acids elaidic acid and oleic acid have exactly the same structural formulae, with one double bond in the chain. However, the shapes of the chains are different, as shown in the diagram. [Figure: Diagrams of elaidic acid and oleic acid] Which row shows the effect of the presence of these fatty acids on the structure and behaviour of a cell surface membrane?
✓ Correct Answer
The correct answer is C: elaidic acid: fits closely with other fatty acids so that the membrane is less fluid at high temperatures, oleic acid: does not fit closely with other fatty acids so that the membrane is more fluid at low temperatures
📋 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