Pick out the correct statement from following

Options

A. In glycolysis, hydration is followed by dephosphorylation
B. In link reaction, `2CO_(2)` are removed from each pyruvic acid
C. One turn of Krebs cycle requires `3NAD^(+)` and 1 FAD
D. In Krebs cycle, dehydration is immediately followed by oxidation

Answer

To solve the question of picking out the correct statement from the given options, we will analyze each option based on our understanding of glycolysis and the Krebs cycle (also known as the citric acid cycle).

### Step-by-Step Solution:

1. **Analyze Option 1**:
- The statement claims that in glycolysis, hydration is followed by dehydration.
- In glycolysis, hydration does occur, but it is not followed by dehydration. Instead, glycolysis consists of a series of reactions that convert glucose into pyruvate, and hydration is part of the process, but it does not directly lead to dehydration.
- **Conclusion**: This statement is incorrect.

2. **Analyze Option 2**:
- The statement claims that in the link reaction, two carbon dioxide molecules are removed from each pyruvic acid.
- The link reaction involves the conversion of pyruvate into acetyl-CoA, where each pyruvate (2 molecules from one glucose) produces one carbon dioxide. Therefore, from two pyruvate molecules, two carbon dioxide molecules are released, not from one.
- **Conclusion**: This statement is incorrect.

3. **Analyze Option 3**:
- The statement claims that one turn of the Krebs cycle requires three NAD+ and one FAD.
- In the Krebs cycle, for each turn, three NAD+ molecules and one FAD molecule are indeed required. This is a well-established fact in cellular respiration.
- **Conclusion**: This statement is correct.

4. **Analyze Option 4**:
- The statement claims that in the Krebs cycle, dehydration is immediately followed by oxidation.
- In the Krebs cycle, oxidation occurs before dehydration in the sequence of reactions. Therefore, this statement is incorrect.
- **Conclusion**: This statement is incorrect.

### Final Answer:
The correct statement is **Option 3**: One turn of the Krebs cycle requires three NAD+ and one FAD.