Leghemoglobin is

Options

A. An oxygen carrier in human blood
B. A protein used as food supplement
C. An oxygen scavenger in root nudules
D. A plant protein with high lysine content

Answer

**Step-by-Step Text Solution:**

1. **Understanding Leghemoglobin:**
- Leghemoglobin is a specialized protein found in the root nodules of leguminous plants. It is similar to hemoglobin found in human blood but serves a different function.

2. **Analyzing the Options:**
- Option A: "An oxygen carrier in human blood" - This describes hemoglobin, not leghemoglobin, so this option is incorrect.
- Option B: "A protein used as food supplement" - This does not accurately describe leghemoglobin, making this option also incorrect.
- Option C: "An oxygen scavenger in root nodules" - This option is correct. Leghemoglobin binds to oxygen in the root nodules, creating a low-oxygen environment that is conducive for nitrogen-fixing bacteria to function.
- Option D: "A plant protein with high lysine content" - While some plant proteins are high in lysine, this does not pertain to leghemoglobin, making this option incorrect.

3. **Function of Leghemoglobin:**
- Leghemoglobin plays a critical role in the nitrogen fixation process. It binds to oxygen, thus reducing its concentration in the root nodules. This is essential because the nitrogen-fixing enzyme, present in symbiotic bacteria (like Rhizobium), is inhibited by high levels of oxygen.

4. **Conclusion:**
- The correct answer is that leghemoglobin is "an oxygen scavenger in root nodules" (Option C). It facilitates the nitrogen-fixing process by maintaining an anaerobic environment.