4.1 What are Enzymes?
- Enzymes: Biological catalysts made of proteins.
- Properties:
- Speed up reactions.
- Not used up in the reaction.
- Specific to one substrate.
4.2 Enzyme Action
- Lock and Key Model: Enzymes have an active site where the substrate fits.
4.3 Factors Affecting Enzyme Activity
- Temperature: Higher temperature increases enzyme activity until optimum temperature (~37°C), after which denaturation occurs.
- pH: Each enzyme has an optimum pH. Extreme pH can denature enzymes.
- Substrate Concentration: Increases enzyme activity until saturation (all active sites are occupied).
- Examples:
- Amylase: Breaks down starch to maltose.
- Protease: Breaks down proteins to amino acids.
- Lipase: Breaks down fats to fatty acids and glycerol.
4.5 Denaturation
- Denaturation: Irreversible change in enzyme shape due to high temperature or extreme pH.