Note: The induced fit model is covered at A-level Biology, not required for GCSE.
Induced Fit Model (Modern, A-level):
- Enzyme active site is flexible and changes shape slightly when substrate binds
- Substrate binding induces a conformational change in the active site
- Better explains enzyme specificity and regulation at molecular level
- Accounts for allosteric control and competitive inhibition
The induced fit model is now accepted as more accurate, but for GCSE you only need the lock-and-key model.
This higher tier covers Beyond GCSE: Induced Fit Model 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 4 of 19 in this topic. This section is most useful once the core foundation idea is secure, because it adds the detail that pushes answers higher.
Practice questions for Enzymes in Digestion
What are enzymes?
Explain the effect of increasing temperature on enzyme activity.
Quick recall flashcards
What does lipase do?
Breaks down lipids (fats) into fatty acids and glycerol. Produced by pancreas, works in small intestine.
What is an enzyme?
A biological catalyst that speeds up chemical reactions by lowering activation energy. Enzymes are proteins with specific 3D shapes.