(i) Temperature, pH and concentration of substrate can influence enzyme activity ?
(ii) ES complex is short lived and dissociates into products (P)
(iii) In exothermic reaction, the energy level of "P" is lower than "S" substrate
(iv) Cofactors play a crucial role in the catalytic activity of the
enzyme.
Which of the above statements are correct ?

Options

A. i, iii and iv
B. ii and iv
C. i, ii and iv
D. i, ii, iii and iv

Answer

To determine which statements about enzyme activity are correct, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (i): Temperature, pH, and concentration of substrate can influence enzyme activity.**
- **Analysis:** This statement is correct. Enzymes have optimal conditions under which they function best. Changes in temperature and pH can denature enzymes or alter their activity, while substrate concentration affects the rate of reaction until saturation is reached.

2. **Statement (ii): ES complex is short-lived and dissociates into products (P).**
- **Analysis:** This statement is also correct. The enzyme-substrate (ES) complex is transient; it forms when the substrate binds to the enzyme and quickly dissociates into products after the reaction occurs.

3. **Statement (iii): In exothermic reaction, the energy level of "P" is lower than "S" substrate.**
- **Analysis:** This statement is correct. In an exothermic reaction, the products (P) have lower energy than the substrates (S) because energy is released during the reaction process.

4. **Statement (iv): Cofactors play a crucial role in the catalytic activity of the enzyme.**
- **Analysis:** This statement is correct as well. Cofactors, which can be metal ions or organic molecules, assist enzymes in catalyzing reactions by helping to stabilize the enzyme-substrate complex or by participating in the reaction.

### Conclusion:
All four statements are correct. Therefore, the answer to the question is that all the statements (i, ii, iii, and iv) are correct.