Skip to content

Loading…

Home
Subjects
Past papers
Key terms
Pricing

My courses

Select your courses

Loading…

Subjects

History
Geography
Biology
Chemistry
Physics
Mathematics
Classics

Resources

Browse courses
Past papers
Key terms & definitions
Pricing

About

Sign up
Log in
Privacy Policy
Terms of Service

© 2026 GradeGen

Not affiliated with any exam board.

Lock and key model — AQA GCSE Biology Definition | GradeGen

Home
Biology
Key terms
Lock and key model

GCSE Biology · key term

Lock and key model

Definition

A model in which a substrate fits an enzyme’s complementary active site like a key fitting a lock.

Used by AQA

How each exam board covers it

AQA GCSE Biology · 8461

Specification 4.2.2.1 · Paper 1

The lock and key model is a simplified way to represent enzyme action. The substrate has a shape complementary to the enzyme’s active site, rather as a key has a shape complementary to its lock.
Revise: The Mechanism and Factors of Enzyme Action

AQA Biology past papers

Related key terms

Active site
Denaturation
Enzyme
Enzyme–substrate complex
Metabolism

Revise Biology with GradeGen

Create a free account to read GCSE Biology revision notes for your exam board and track your progress.

Sign Up to Start Revising Log In

Rate of reaction