Enzymes

Syllabus tag: KCSE | Biology | Form 1 | Topic 4 Cell Physiology

Lesson objectives

By the end of this topic, you should be able to:

• Define an enzyme and state its properties.
• Explain the lock and key mechanism of enzyme action.
• Describe the effects of temperature, pH and concentration on enzyme activity.
• State the applications of enzymes.

Summary

Enzymes are protein catalysts made by living cells. They speed up reactions without being used up, and each acts on one substrate only — a property called specificity, explained by the lock and key model. They are denatured by high temperature and extreme pH, and denaturation is permanent.