Thermoregulation and osmoregulationSpec 7.10B
Thermoregulation: the effect on enzyme activity
Thermoregulation is the control of body temperature. Core body temperature is kept at about 37°C, which is the optimum temperature for most enzymes in the body.
- If the temperature rises too far, enzymes are denatured. The shape of the active site changes, so the substrate no longer fits and the reaction stops.
- If the temperature falls too far, enzymes work more slowly, so reactions in cells are too slow.
Osmoregulation: the effect on animal cells
Osmoregulation is the control of the water content of the blood. Animal cells have no cell wall, so water moving by osmosis changes them.
| Blood water content | Effect on animal cells |
|---|---|
| Too high (blood too dilute) | Water enters the cells by osmosis. The cells swell and may burst |
| Too low (blood too concentrated) | Water leaves the cells by osmosis. The cells shrink |