BI-1406
Effect of temperature and pH on enzymes
Biology · Secondary 4 · Hard · Effect of temperature and pH on enzymes
An enzyme that digests protein shows maximum activity at 40 °C. When the temperature is increased to 70 °C, the rate of reaction drops to almost zero and does not recover when cooled back to 40 °C.
Which statement best explains this observation?
Which statement best explains this observation?
- The enzyme is denatured at 70 °C and its active site changes shape permanently.
- The enzyme is used up at 70 °C and cannot be made again.
- The substrate is denatured at 70 °C but the enzyme remains unchanged.
- The enzyme becomes dormant at 70 °C and reactivates when cooled.
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