Catalytic activity is ………... when ………... is removed from the enzyme which testifies that they play cruial role in the catalytic activity of the enzyme .

Options

A. Lost, Co-factor
B. Intensified , Co-factor
C. Lost , Inhibitor
D. both (a) and (c)

Answer

To solve the question regarding the catalytic activity of enzymes, we will analyze the options provided and understand the role of cofactors in enzymatic reactions.

### Step-by-Step Solution:

1. **Understanding the Question**: The question states that "catalytic activity is ………... when ………... is removed from the enzyme." We need to fill in the blanks with appropriate terms that relate to the role of certain components in enzyme activity.

2. **Identifying Key Components**: The question hints at a crucial component that, when removed, affects the catalytic activity of the enzyme. This suggests that we are looking for a component that is essential for the enzyme's function.

3. **Considering the Options**:
- **Option A**: "lost and co-factor" - This suggests that the catalytic activity is lost when the co-factor is removed. This is a strong candidate because cofactors are known to be essential for the activity of many enzymes.
- **Option B**: "intensified cofactor" - This option does not make logical sense in the context of the question.
- **Option C**: "lost and inhibitor" - An inhibitor generally decreases enzyme activity, but it is not the same as a co-factor, which is necessary for activity.
- **Option D**: "both A and C" - Since Option C is incorrect, this option cannot be correct.

4. **Conclusion**: Based on the analysis, the correct answer is **"Catalytic activity is lost when co-factor is removed from the enzyme."** This indicates that cofactors play a crucial role in the catalytic activity of enzymes.

### Final Answer:
Catalytic activity is **lost** when **co-factor** is removed from the enzyme which testifies that they play a crucial role in the catalytic activity of the enzyme.