Which one of the following pairs is not correctly matched?

Options

A. Copper `" " `Plastocyanin
B. Sulphur ` " " ` Serine
C. Molybdenum Nitrate reductase
D. Zinc ` " " `Alcohol dehydrogenase

Answer

To solve the question "Which one of the following pairs is not correctly matched?", we will analyze each of the given pairs one by one.

### Step 1: Analyze the first pair - Copper and Plastocyanin
- **Explanation**: Plastocyanin is a metalloprotein that contains copper. It plays a role in the electron transport chain in plants.
- **Conclusion**: This pair is correctly matched.

### Step 2: Analyze the second pair - Sulfur and Serine
- **Explanation**: Serine is an amino acid that does not contain sulfur. Instead, sulfur is present in other amino acids like cysteine and methionine.
- **Conclusion**: This pair is not correctly matched.

### Step 3: Analyze the third pair - Molybdenum and Nitrate Reductase
- **Explanation**: Molybdenum is an essential component of the enzyme nitrate reductase, which is involved in the nitrogen cycle.
- **Conclusion**: This pair is correctly matched.

### Step 4: Analyze the fourth pair - Zinc and Alcohol Dehydrogenase
- **Explanation**: Zinc acts as a cofactor for the enzyme alcohol dehydrogenase, which is involved in the metabolism of alcohol.
- **Conclusion**: This pair is correctly matched.

### Final Conclusion
- The only pair that is not correctly matched is **Sulfur and Serine**.

### Answer
The correct answer to the question is **Sulfur and Serine**.

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