Equal samples of a human enzyme are kept at three temperatures for ten minutes. They are then all tested at 37 ∘C37\ ^\circ\mathrm{C}37 ∘C using identical conditions.
Table
| Earlier temperature in ∘C^\circ\mathrm{C}∘C | Relative activity when tested at 37 ∘C37\ ^\circ\mathrm{C}37 ∘C |
|---|---|
| 10 | 100 |
| 37 | 100 |
| 65 | 8 |
Which conclusion best explains why thermoregulation is important?
Cooling and strong heating both permanently alter most active sites.
Cooling permanently alters most active sites, whereas strong heating does not.
Strong heating only slows collisions, whereas cooling permanently changes active sites.
Strong heating can permanently alter active sites, whereas cooling need not do so.
44 exam-style questions on Edexcel GCSE Biology 7.3 Homeostasis and thermoregulation, covering 7.3.1 Importance of a constant internal environment, 7.3.2 Importance of homeostasis, 7.3.3a Thermoregulation via the skin and hypothalamus, and 7.3.3b Vasoconstriction and vasodilation in thermoregulation. Each one has a worked solution and a mark scheme showing where the marks go.