Role of enzymes in biochemical reactions

1. Introduction to Enzymes

1. Enzymes are biological catalysts that speed up chemical reactions in living organisms.
2. They are mostly proteins, except for some RNA molecules known as ribozymes.
3. Enzymes work by lowering the activation energy of a reaction.
4. They remain unchanged after the reaction and can be used multiple times.

2. Properties of Enzymes

1. Highly Specific: Each enzyme acts on a specific substrate.
2. Active Site: The region where the substrate binds and the reaction occurs.
3. Efficient Catalysts: Can increase reaction rates by millions of times.
4. Temperature and pH Sensitive: Function optimally at specific conditions.
5. Can Be Regulated: Enzyme activity can be enhanced or inhibited.

3. Mechanism of Enzyme Action

1. Follows the Lock and Key Model or Induced Fit Model.
2. The substrate binds to the enzyme's active site.
3. A temporary enzyme-substrate complex is formed.
4. The reaction occurs, and the product is released.
5. The enzyme returns to its original state and is ready for another reaction.

4. Types of Enzymes

1. Oxidoreductases: Catalyze oxidation-reduction reactions (e.g., dehydrogenases).
2. Transferases: Transfer functional groups between molecules (e.g., kinases).
3. Hydrolases: Break bonds using water (e.g., amylase, protease).
4. Lyases: Add or remove groups without water (e.g., decarboxylases).
5. Isomerases: Convert molecules into their isomers (e.g., phosphoglucoisomerase).
6. Ligases: Join two molecules together (e.g., DNA ligase).

5. Factors Affecting Enzyme Activity

1. Temperature: Enzymes have an optimum temperature; too high or too low temperatures reduce activity.
2. pH: Each enzyme has an optimal pH range.
3. Substrate Concentration: Increasing substrate increases reaction rate up to a certain limit.
4. Inhibitors: Can decrease enzyme activity (competitive or non-competitive inhibition).
5. Cofactors and Coenzymes: Some enzymes require metal ions or vitamins to function.

6. Importance of Enzymes in Biological Processes

1. Digestion: Enzymes like amylase, protease, and lipase help break down food.
2. Metabolism: Enzymes regulate metabolic pathways like glycolysis and the Krebs cycle.
3. DNA Replication: DNA polymerase is essential for copying genetic material.
4. Respiration: ATP synthase produces energy in cells.
5. Detoxification: Catalase helps break down hydrogen peroxide.

7. Industrial and Medical Applications

1. Pharmaceutical Industry: Used in drug synthesis and production of antibiotics.
2. Food Industry: Enzymes like pectinase and lactase are used in food processing.
3. Textile Industry: Enzymes like cellulase are used in fabric processing.
4. Biotechnology: Enzymes play a key role in genetic engineering.
5. Medical Diagnostics: Enzymes like glucose oxidase help in blood sugar testing.

8. Conclusion

1. Enzymes are crucial for life, driving essential biochemical reactions.
2. They are used in medicine, industry, and research for various applications.
3. Understanding enzyme mechanisms helps in disease treatment, food production, and biotechnology.