DP Biology (first assessment 2025)

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Question 22M.2.SL.TZ2.a

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Date May 2022 Marks available [Maximum mark: 2] Reference code 22M.2.SL.TZ2.a
Level SL Paper 2 Time zone TZ2
Command term Explain Question number a Adapted from N/A
a.
[Maximum mark: 2]
22M.2.SL.TZ2.a

Explain the decrease in activity of the enzyme on either side of the optimum temperature.

[2]

Markscheme
  1. as temperature rises/is higher (than optimal temperature), the enzyme is denatured;
  2. as the temperature drops the enzyme molecules have less kinetic energy
    OR
    fewer successful collisions;

OWTTE

Examiners report

In a. many incorrectly stated that the enzyme was denatured either side of the optimum. Denaturation was reasonably well known, but the explanation for increased activity with rising temperature was not. Surprisingly some candidates missed the obvious references to temperature and wrote about pH instead. Knowledge of the enzymes involved in gene transfer was very patchy, with over a quarter of candidates leaving it blank. This was the worst scoring question on the paper.

Syllabus sections