How temperature affects enzymes
Activity rises to an optimum, then falls fast as the enzyme denatures.
The common mistake
Saying enzymes 'die' at high temperatures, or that they work faster forever as it heats up.
Instead: Heat speeds collisions up to the optimum. Past it, the active site changes shape (denatures) and the substrate no longer fits.
Worked example with Guide me
Why does a human enzyme stop working at 60°C?
- Sugar · What's the optimum for most human enzymes?Student · About 37°C.
- Sugar · What happens to the active site at 60°C?Student · It changes shape.
Answer: It denatures — the substrate no longer fits the active site.
Try 3 practice questions
1. What does 'denature' mean?
Show answer
The active site permanently changes shape
2. What else changes enzyme activity besides temperature?
Show answer
pH (also substrate concentration)
3. Are enzymes used up in a reaction?
Show answer
No, they can be reused
Quick answers
- What is the most common mistake with how temperature affects enzymes?
- Saying enzymes 'die' at high temperatures, or that they work faster forever as it heats up.
- How do I get how temperature affects enzymes right?
- Heat speeds collisions up to the optimum. Past it, the active site changes shape (denatures) and the substrate no longer fits.
- Can you show a worked example?
- Why does a human enzyme stop working at 60°C? It denatures — the substrate no longer fits the active site.
Related concepts
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