Catalytic group of active site weakens substrate bonds by

Options

A. Channel energy
B. Electrophilic changes
C. Nucleophilic changes
D. Both B and C.

Answer

### Step-by-Step Solution:

1. **Understanding the Enzyme-Substrate Complex**:
- Enzymes are biological catalysts that speed up chemical reactions. They bind to substrates (the molecules upon which enzymes act) to form an enzyme-substrate complex.

2. **Role of the Active Site**:
- The active site of an enzyme is the specific region where the substrate binds. This site contains catalytic groups that facilitate the conversion of substrates into products.

3. **Function of Catalytic Groups**:
- Catalytic groups in the active site can be classified as either electrophiles or nucleophiles.
- **Electrophiles** are electron-deficient and attract electrons.
- **Nucleophiles** are electron-rich and can donate electrons.

4. **Mechanism of Bond Weakening**:
- When the substrate binds to the enzyme, the catalytic groups exert forces on the substrate.
- Electrophilic catalytic groups attract electrons from the substrate, while nucleophilic groups may donate electrons to the substrate.
- This interaction creates strain on the substrate bonds, making them weaker.

5. **Formation of Products**:
- As the bonds weaken due to the strain from the catalytic groups, the substrate is more likely to undergo a chemical reaction, leading to the formation of products.
- The weakened bonds facilitate the conversion of the substrate into the product, completing the catalytic process.

6. **Conclusion**:
- The catalytic group of the active site weakens substrate bonds by either attracting electrons (electrophilic action) or donating electrons (nucleophilic action), resulting in the formation of the product.