Which of the following combinations is correct?

Options

A. Metal ions loosely attached with Apoenzyme - Activators.
B. Non - protein organic part attached tightly to the Apoenzyme - Prosthetic group .
C. Non - protein organic part attached loosely to the Apoenzyme - Coenzyme .
D. all of these

Answer

To solve the question regarding the correct combinations of terms related to enzymes, we will analyze each statement provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding Apoenzyme and Cofactors**:
- An apoenzyme is the protein part of an enzyme that requires a cofactor to be active.
- Cofactors can be metal ions or organic molecules.

2. **Analyzing the First Statement**:
- The first statement claims that a metal ion loosely connected to the apoenzyme is termed as an activator.
- This statement is **correct**. Metal ions can act as activators when they bind loosely to the apoenzyme.

3. **Analyzing the Second Statement**:
- The second statement states that a non-protein organic part attached to the apoenzyme is termed as a prosthetic group.
- This statement is **incorrect**. A non-protein organic part that is tightly bound to the apoenzyme is called a prosthetic group, not loosely attached.

4. **Analyzing the Third Statement**:
- The third statement claims that a non-protein organic part attached loosely to the apoenzyme is known as a coenzyme.
- This statement is **correct**. Coenzymes are indeed non-protein organic molecules that bind loosely to the apoenzyme.

5. **Conclusion**:
- Based on the analysis:
- First statement: Correct (Activator)
- Second statement: Incorrect (should be prosthetic group for tightly bound)
- Third statement: Correct (Coenzyme)
- Therefore, the correct answer to the question is **Option D: All of these** is not correct because the second statement is incorrect.

### Final Answer:
The correct combination is that the first and third statements are correct, while the second statement is incorrect.

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