Effect of Temperature and pH on Enzyme Activity

Enzymes are biological catalysts that speed up chemical reactions in living organisms.
Each enzyme has an optimum temperature at which it works best.
If the temperature is too low, the rate of enzyme activity is slow because the molecules move slowly and do not collide often.
As the temperature increases, so does the rate of the reactions - up to a certain point, known as the optimum temperature. This is typically around 37°C in humans.
Beyond the optimum temperature, the enzyme molecules start to lose their shape (denature) and the active site changes, causing the rate of reaction to decrease. At high enough temperatures, the enzyme will stop working entirely.
Similarly, enzymes also have an optimum pH at which they function most efficiently.
The pH scale ranges from 0 to 14. A pH of 7 is neutral, below 7 is acidic and above 7 is alkaline or basic. Each enzyme works best at a specific pH level.
If the pH is too high (too alkaline) or too low (too acidic), it can affect the shape of the enzyme and its active site, reducing its activity. Extreme pH values can denature the enzyme, rendering it inactive.
It is important to remember that different enzymes work best at different pH levels. For example, protease enzymes in the stomach function best in acidic conditions (pH 2), while those in the small intestine operate in more alkaline conditions (pH 7-8).
In summary, both temperature and pH can affect the rate at which enzymes work. If either factor strays too far from an enzyme’s optimum conditions, the enzyme can denature and lose its ability to catalyse reactions. It is essential, therefore, that cells maintain stable internal conditions (homeostasis) to ensure efficient enzyme activity.