This resource is a GCSE Biology enzymes revision booklet designed to help students secure the key marks in the enzymes topic. It includes

• Core knowledge and definitions (enzyme, substrate, active site, products, optimum, denature) and the lock-and-key model of specificity.

• Clear explanations of factors affecting enzyme activity: temperature, pH, substrate concentration, and enzyme concentration.

• A full Required Practical on the effect of pH on amylase using the iodine test, with equipment, method, variables, safety, reliability, results table template, and graph expectations.

• Brief guidance on other common enzyme practicals (catalase with hydrogen peroxide, lipase with milk/indicator).

• A 4-day 10-minute revision plan

• Multiple-choice exam practice questions with answers.

• A final checklist to check progress.