The enzyme nitrogenase is highly sensitive to the molecular oxygen as it requires anaerobic condition. In nodule anaerobic condition is provided by

Options

A. Nod factor
B. bacteroids
C. Leghaemoglobin
D. Auxin

Answer

To solve the question regarding how anaerobic conditions are provided in the nodule for the enzyme nitrogenase, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Nitrogenase and its Sensitivity**:
- Nitrogenase is an enzyme that plays a crucial role in nitrogen fixation, converting atmospheric nitrogen (N₂) into ammonia (NH₃).
- This enzyme is highly sensitive to molecular oxygen (O₂) and requires anaerobic (oxygen-free) conditions to function effectively.

2. **Role of Root Nodules**:
- Nitrogen-fixing bacteria, such as Rhizobium, form symbiotic relationships with the roots of certain plants, leading to the formation of root nodules.
- These nodules provide a specialized environment where nitrogen fixation can occur.

3. **Components of the Nodule**:
- The nodule consists of various components, including the nitrogenase enzyme and leghemoglobin.
- Leghemoglobin is a protein that binds oxygen, similar to hemoglobin in blood.

4. **Function of Leghemoglobin**:
- Leghemoglobin serves as an oxygen scavenger. It binds to oxygen molecules, reducing the concentration of free oxygen in the nodule.
- By binding to oxygen, leghemoglobin prevents it from reaching the nitrogenase enzyme, thereby maintaining the anaerobic conditions necessary for nitrogen fixation.

5. **Conclusion**:
- Since leghemoglobin effectively binds oxygen and protects nitrogenase from oxidative damage, it is the component that provides anaerobic conditions in the nodule.
- Therefore, the correct answer to the question is **leghemoglobin**.

### Final Answer:
In the nodule, anaerobic conditions are provided by **leghemoglobin**.