This topic summary covers Knowledge Organiser 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 18 of 19 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 18 of 19
Practice
20 questions
Recall
25 flashcards
Knowledge Organiser
Key Terms
- Enzyme — biological catalyst; protein; not used up
- Active site — specific shape; complementary to substrate
- Substrate — molecule that fits the active site
- Denaturation — permanent shape change of active site
- Optimum — conditions giving fastest reaction rate
- Emulsification — bile breaks large fat droplets into smaller ones
Must-Know Facts
- Amylase: starch to maltose; found in mouth (saliva) and pancreas; optimum pH 7
- Pepsin: proteins to amino acids; found in stomach; optimum pH 1.5
- Trypsin: proteins to amino acids; found in small intestine; optimum pH 8.5
- Lipase: lipids to fatty acids and glycerol; pancreas and small intestine; optimum pH 8
- Bile: produced by liver, stored in gall bladder, released into duodenum; NOT an enzyme
- Bile functions: emulsifies fats (increases surface area for lipase) AND neutralises stomach acid
- High temperature above optimum = denaturation (irreversible)
- Low temperature = fewer collisions, slower rate (reversible)
- Rate of reaction = amount of product formed ÷ time taken