OrganisationDeep Dive

Factors Affecting Enzyme Activity

Part of Enzymes in DigestionGCSE Biology

This deep dive covers Factors Affecting Enzyme Activity 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 8 of 19 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 8 of 19

Practice

20 questions

Recall

25 flashcards

Factors Affecting Enzyme Activity

1. Temperature

  • Low temperature: Enzymes work slowly (less kinetic energy)
  • Optimal temperature: Maximum enzyme activity (usually 37°C for human enzymes)
  • High temperature: Enzymes denature (active site changes shape permanently)
  • Q10 rule: Enzyme activity roughly doubles for every 10°C increase (until denaturation)

2. pH

  • Each enzyme has an optimal pH range
  • Wrong pH: Changes enzyme shape, reduces activity
  • Extreme pH: Permanent denaturation
  • Examples: Pepsin (pH 1.5), Amylase (pH 7), Trypsin (pH 8.5)

3. Enzyme Concentration

  • More enzymes: More active sites available
  • Rate increases until substrate becomes limiting factor
  • Plateau reached when all substrate is being used

4. Substrate Concentration

  • More substrate: More collisions with active sites
  • Rate increases until enzymes become limiting factor
  • Vmax: Maximum rate when all enzymes are saturated

Keep building this topic

Read this section alongside the surrounding pages in Enzymes in Digestion. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Enzymes in Digestion

What are enzymes?

  • A. Carbohydrates that provide energy for cells
  • B. Biological catalysts that speed up chemical reactions
  • C. Proteins that are used up during digestion
  • D. Molecules that store genetic information
1 markfoundation

Explain the effect of increasing temperature on enzyme activity.

3 marksstandard

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.

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