This deep dive covers Enzyme Models: Lock and Key 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 3 of 19 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Enzyme Models: Lock and Key
Lock and Key Model:
- Enzyme active site has a fixed, specific shape
- Substrate fits exactly into the active site — like a key in a lock
- Only one substrate (or very similar substrates) can bind — this is enzyme specificity
- Explains why each enzyme only catalyses one type of reaction
Practice questions for Enzymes in Digestion
What are enzymes?
Explain the effect of increasing temperature on enzyme activity.
Quick recall flashcards
What is an enzyme?
A biological catalyst that speeds up chemical reactions by lowering activation energy. Enzymes are proteins with specific 3D shapes.
What does lipase do?
Breaks down lipids (fats) into fatty acids and glycerol. Produced by pancreas, works in small intestine.