This exam focus covers Exam Focus within Enzymes in Digestion for GCSE Biology. Enzyme structure and function, digestive enzymes, factors affecting enzyme activity, lock and key model, and practical investigations It is section 17 of 19 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 17 of 19
Practice
20 questions
Recall
25 flashcards
Exam Focus
Exam FavouriteEnzymes and Digestion is one of the highest-frequency topics in AQA Biology Paper 1. Expect at least one structured question on enzymes in every exam.
How it is tested:
- 6-mark "explain" questions: "Explain how temperature affects enzyme activity" — these require a chain of reasoning from molecular mechanism through to measurable effect, including denaturation.
- Graph interpretation: You will be given a rate-versus-pH or rate-versus-temperature graph and asked to identify the optimum, explain the shape of the curve, or compare two enzymes.
- Required Practical 4 (food tests): Method, reagent, colour change, and what each test detects.
- Required Practical 5 (amylase and pH): Control variables, expected results, how to measure rate using the iodine method.
- Calculations: Rate = amount of product / time; initial rate from a tangent to a curve.
Command words to watch: "Explain" requires mechanism (active site shape + substrate fit). "Describe" requires stating what happens without always explaining why. "Suggest" means you must apply knowledge to an unfamiliar context.