Study Notes
Enzymes are proteins that act as biological catalysts, speeding up chemical reactions without being consumed. They have a specific active site that fits the substrate like a lock and key, forming an enzyme-substrate complex to produce a product. Enzymes are sensitive to temperature and pH, with each having an optimum range where they function best. Extreme conditions can denature enzymes, altering their structure and function.
- Enzymes — proteins that function as biological catalysts. Example: Amylase breaks down starch into maltose.
- Active Site — the specific region of an enzyme where the substrate binds. Example: The active site of catalase binds hydrogen peroxide.
- Substrate — the molecule upon which an enzyme acts. Example: Starch is the substrate for amylase.
- Product — the substance(s) formed from the substrate by the enzyme. Example: Maltose is the product of starch breakdown by amylase.
- Denaturation — the process where enzymes lose their shape and functionality due to extreme conditions. Example: High temperatures can denature enzymes like pepsin.
Exam Tips
Key Definitions to Remember
- Enzymes are proteins that act as biological catalysts.
- The active site is the part of an enzyme where the substrate binds.
- Denaturation is the loss of enzyme structure and function due to extreme conditions.
Common Confusions
- Confusing the substrate with the product.
- Thinking enzymes are consumed in reactions.
Typical Exam Questions
- What is the role of enzymes in biological reactions? Enzymes speed up reactions by lowering activation energy.
- How does temperature affect enzyme activity? Enzymes have an optimum temperature; too high or low can denature them.
- Why is the active site important? It is where the substrate binds and the reaction occurs.
What Examiners Usually Test
- Understanding of enzyme specificity and the lock and key model.
- Effects of temperature and pH on enzyme activity.
- Differences between intracellular and extracellular enzymes.