Thermoregulation

This lesson covers how the human body maintains a constant core temperature of approximately 37°C — a process called thermoregulation. This is a key example of homeostasis and negative feedback for Edexcel GCSE Biology (1BI0) Topic 7.

---

Why Must Body Temperature Be Controlled?

The core body temperature must be maintained at approximately 37°C because this is the optimum temperature for the enzymes that control the body's chemical reactions.

If Temperature Is Too High	If Temperature Is Too Low
Enzymes begin to denature — their active site changes shape permanently	Chemical reactions become too slow — metabolic rate decreases
Proteins unfold and lose their function	Cells cannot carry out vital reactions efficiently
Cell damage occurs	In extreme cases: hypothermia, organ failure
In extreme cases: heat stroke, organ failure, death	In extreme cases: death

Exam Tip: The optimum temperature for enzymes is 37°C, NOT 37°C exactly. It is an approximation. Always say "approximately 37°C" or "about 37°C" in your answers.

---

The Thermoregulatory Centre