Which of the following statements is incorrect about leghaemoglobin?

Options

A. in acts as `O_(2)` scavenger
B. it imparts pink or red colour to the nodules
C. it combines with `O_(2)` and protects nitrogenase.
D. It is a Mo-Fe

Explanation

To determine which statement about leghemoglobin is incorrect, we will analyze each statement based on our understanding of leghemoglobin and its functions.

### Step-by-Step Solution:

1. **Understanding Leghemoglobin**:
- Leghemoglobin (Lb) is a red-pink pigment found in the root nodules of legumes, produced by root hair cells in response to rhizobium bacteria.

2. **Function of Leghemoglobin**:
- Its primary role is to regulate oxygen supply in the root nodules. It creates an anaerobic environment necessary for the enzyme nitrogenase to function effectively.

3. **Analyzing the Statements**:
- **Statement 1**: "It acts as an oxygen scavenger."
- **Analysis**: This statement is correct. Leghemoglobin binds to oxygen, thereby reducing its concentration and creating an anaerobic environment.

- **Statement 2**: "It imparts pink or red color to the nodules."
- **Analysis**: This statement is also correct. The red-pink color of leghemoglobin gives the nodules their characteristic hue.

- **Statement 3**: "It combines with oxygen and protects nitrogenase."
- **Analysis**: This statement is correct as well. By binding to oxygen, leghemoglobin protects the nitrogenase enzyme from being inactivated by oxygen.

- **Statement 4**: "It is a molybdenum iron protein."
- **Analysis**: This statement is incorrect. Molybdenum iron proteins refer to nitrogenase, not leghemoglobin. Leghemoglobin is a heme protein, not a molybdenum iron protein.

4. **Conclusion**:
- The incorrect statement about leghemoglobin is: "It is a molybdenum iron protein."

### Final Answer:
The incorrect statement about leghemoglobin is: **"It is a molybdenum iron protein."**

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