Arrange the steps of catalytic action of an enzyme in order and select the correct option
I. The enzyme releases the products of the reaction and the enzyme is free to bind to another substrate
II. The active site of enzyme is in close proximity of the substrate and breaks the chemical bonds of the substrate
III. The binding of substrate induces the enzyme to alter its shape fitting more tightly around substrate.
VI. The substrate binds to the active site of the enzyme

Options

A. IV,III,II,I
B. III,III,I,IV
C. IV,II,I,II
D. II,I,IV,III

Answer

To arrange the steps of the catalytic action of an enzyme in the correct order, we need to analyze each statement provided:

1. **Step VI**: The substrate binds to the active site of the enzyme.
- This is the first step in the catalytic action. The enzyme has a specific region called the active site where the substrate molecule binds.

2. **Step III**: The binding of substrate induces the enzyme to alter its shape fitting more tightly around the substrate.
- Once the substrate is bound to the active site, the enzyme undergoes a conformational change, which allows it to fit more snugly around the substrate. This is often referred to as the "induced fit" model.

3. **Step II**: The active site of the enzyme is in close proximity to the substrate and breaks the chemical bonds of the substrate.
- After the enzyme has altered its shape, it can effectively catalyze the reaction by breaking the chemical bonds of the substrate, leading to the formation of products.

4. **Step I**: The enzyme releases the products of the reaction and the enzyme is free to bind to another substrate.
- Finally, after the reaction has occurred and products have been formed, the enzyme releases these products and is now free to bind to another substrate molecule.

Putting these steps in order, we have:
- VI → III → II → I

Thus, the correct order of the steps of catalytic action of an enzyme is:
1. VI: The substrate binds to the active site of the enzyme.
2. III: The binding of substrate induces the enzyme to alter its shape fitting more tightly around the substrate.
3. II: The active site of the enzyme is in close proximity to the substrate and breaks the chemical bonds of the substrate.
4. I: The enzyme releases the products of the reaction and the enzyme is free to bind to another substrate.

**Final Answer**: The correct order is VI, III, II, I.

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