Biochemistry (BP203T)

1. Introduction to Enzymes

Enzymes are biological catalysts that speed up biochemical reactions without being consumed. Most enzymes are proteins, although some RNA molecules also exhibit catalytic activity.

2. Properties of Enzymes

• High specificity for substrates
• Increase reaction rate
• Reusable and efficient
• Active at optimum pH and temperature

3. Mechanism of Enzyme Action

Enzymes form an enzyme–substrate complex at the active site. Two models explain this interaction:

• Lock and Key model
• Induced Fit model

4. Enzyme Kinetics

Enzyme kinetics deals with the study of reaction rates. Michaelis– Menten equation explains the relationship between substrate concentration and reaction velocity.

5. Factors Affecting Enzyme Activity

• Substrate concentration
• Enzyme concentration
• Temperature
• pH
• Inhibitors

6. Enzyme Inhibition

Enzyme inhibitors reduce enzyme activity. They may be:

• Competitive inhibitors
• Non-competitive inhibitors
• Uncompetitive inhibitors

7. Pharmaceutical Importance

Enzymes are widely used as diagnostic agents and therapeutic drugs. Many drugs act by inhibiting specific enzymes involved in disease processes.