Which of the following is correct in an enzyme-controlled reaction ?

Options

A. `E + S hArr E + P`
B. `E+S hArr ES hArr EP hArr E +P`
C. `E+S hArr ES hArr E`
D. `E+S hArr P hArr E+P`

Answer

To solve the question "Which of the following is correct in an enzyme-controlled reaction?" we need to understand the basic mechanism of how enzymes function in biochemical reactions. Here’s a step-by-step breakdown:

### Step-by-Step Solution:

1. **Understanding Enzymes**: Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are typically proteins and have a specific region called the active site where substrates bind.

**Hint**: Remember that enzymes are not consumed in the reaction; they can be reused.

2. **Formation of Enzyme-Substrate Complex**: When a substrate (S) binds to the enzyme (E) at the active site, they form an enzyme-substrate complex (ES). This is the first step in the reaction.

**Hint**: Think of the enzyme as a lock and the substrate as a key that fits into it.

3. **Conversion to Product**: The enzyme then catalyzes the conversion of the substrate into a product (P). This leads to the formation of an enzyme-product complex (EP).

**Hint**: The enzyme facilitates the transformation of the substrate into a product without altering itself.

4. **Release of Product**: Finally, the product (P) is released from the enzyme, and the enzyme returns to its original state, ready to catalyze another reaction. This can be summarized as E + S → ES → EP → E + P.

**Hint**: The enzyme is unchanged after the reaction, which allows it to participate in multiple reactions.

5. **Identifying the Correct Statement**: Based on the understanding of these steps, we can analyze the options given in the question to determine which one accurately describes the process of enzyme action.

### Conclusion:
The correct representation of an enzyme-controlled reaction is E + S ↔ ES ↔ E + P, where E is the enzyme, S is the substrate, and P is the product.