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Cambridge O Level Biology 5090

Foundations

Enzymes

Explain enzyme specificity and interpret how temperature, pH and concentration affect reaction rate.
5090 syllabus routeConcept · skill · exam language

What to know

Build the topic around four anchors.

  1. 01Active sites and specificity
  2. 02Temperature and kinetic energy
  3. 03pH and enzyme shape
  4. 04Rate investigations and controls

Exam skills

What the paper asks you to do

  • Describe and explain rate graphs
  • Plan a fair enzyme investigation
  • Use collision and denaturation language accurately

Common mistakes

Where marks disappear

  • Saying enzymes are killed
  • Treating optimum as the same for every enzyme
  • Describing a graph without explaining the change

Structured practice

Answer these without looking back.

For each prompt, write the biological chain clearly enough that every mark-worthy link is visible.

  1. 01Explain the shape of a temperature-rate curve.
  2. 02Identify controls in an amylase experiment.
  3. 03Predict the effect of extreme pH on an active site.

Continue learning

Read the connected explanation.

Understand what an active site really does, why rates change, and how competitive and non-competitive inhibitors differ.

Next topicPlant nutrition

This independent teaching resource follows the Cambridge O Level Biology 5090 syllabus direction and is not endorsed by Cambridge International Education.