How many of the following statements are correct regarding properties of enzyme ?
(i) It lowers down the activation energy of the reaction .
(ii) An active site of the enzyme is the pocket into which the substate fits .
(iii) The catalytic structure of most of the enzyme is globular and primary .
(iv) Carbonic anhydrase enzyme is considered as the fastest enzyme.

Options

A. 2
B. 3
C. 4
D. 1

Answer

To determine how many statements regarding the properties of enzymes are correct, we will analyze each statement one by one.

1. **Statement (i): It lowers down the activation energy of the reaction.**
- **Analysis:** This statement is correct. Enzymes act as catalysts and lower the activation energy required for a reaction to occur, thereby increasing the rate of the reaction.

2. **Statement (ii): An active site of the enzyme is the pocket into which the substrate fits.**
- **Analysis:** This statement is also correct. The active site of an enzyme is indeed a specific region that binds to the substrate, forming an enzyme-substrate complex.

3. **Statement (iii): The catalytic structure of most of the enzyme is globular and primary.**
- **Analysis:** This statement is incorrect. While enzymes are typically globular proteins, their catalytic activity is primarily due to their tertiary and quaternary structures, not just the primary structure. The primary structure refers to the sequence of amino acids, which does not directly confer catalytic activity.

4. **Statement (iv): Carbonic anhydrase enzyme is considered as the fastest enzyme.**
- **Analysis:** This statement is correct. Carbonic anhydrase is known to be one of the fastest enzymes, facilitating the conversion of carbon dioxide and water into carbonic acid at a very high rate.

**Summary of Correct Statements:**
- Correct statements: (i), (ii), and (iv).
- Incorrect statement: (iii).

**Total number of correct statements:** 3.

### Final Answer:
**3 statements are correct.**