Topic 5 of 21 · 1 of 1 modules ready

Enzymes

The protein catalysts that make life’s reactions fast enough, and what stops them working.

Modules

Module 1 · syllabus 5.1 · 3 parts
Enzymes
What temperature does an enzyme work best at?
Mix amylase with starch in a water bath and put a drop of the mixture onto iodine every 30 seconds until the starch has gone. Time it at six temperatures and three pH values, work out relative rates, and look inside the mixture at the active sites.
1. Catalysts in living things Catalysts and enzymes: the active site, the enzyme–substrate complex and why each enzyme has one job
2. Temperature and enzymes Timing amylase at different temperatures: optimum temperature, collisions and denaturation
3. pH and enzymes Amylase at different pH values: buffers, optimum pH and the shape of the active site
Experiment Amylase and starch on iodine · time the end point at six temperatures and three pH values
Open module Experiment Teacher pack

Module 1 · syllabus 5.1 · 3 parts

Enzymes

What temperature does an enzyme work best at?

Mix amylase with starch in a water bath and put a drop of the mixture onto iodine every 30 seconds until the starch has gone. Time it at six temperatures and three pH values, work out relative rates, and look inside the mixture at the active sites.

Catalysts in living things Catalysts and enzymes: the active site, the enzyme–substrate complex and why each enzyme has one job
Temperature and enzymes Timing amylase at different temperatures: optimum temperature, collisions and denaturation
pH and enzymes Amylase at different pH values: buffers, optimum pH and the shape of the active site

Experiment Amylase and starch on iodine · time the end point at six temperatures and three pH values

Open module Experiment Teacher pack

Syllabus statements for this topic · for teachers · 9 statements

Core for every pupil · Supplement also for Extended entry. Paraphrased from the Cambridge IGCSE Biology 0610 syllabus (2026–2028); check the official syllabus for exact wording.

5.1 Enzymes

Covered in Enzymes

5.1.1Catalyst: speeds a reaction, itself unchangedC
5.1.2Enzymes as protein biological catalystsC
5.1.3Why life needs enzyme-speeded reactionsC
5.1.4Active site complementary to its substrateC
5.1.5Investigate temperature and pH effects on enzymesC
5.1.6Enzyme–substrate complex and productsS
5.1.7Enzyme specificity from active-site shapeS
5.1.8Temperature effect: collisions, shape, denaturationS
5.1.9pH effect: shape, fit and denaturationS