Calmodulin is

Options

A. Carotene binding protein
B. Cadmiun binding protein
C. Calcium binding protein
D. Chlorohyll binding protein.

Answer

**Step-by-Step Solution:**

1. **Understanding Calmodulin**: Calmodulin is a protein that plays a crucial role in various cellular processes. It is known for its ability to bind calcium ions.

2. **Identifying the Function**: Calmodulin functions as a calcium-binding messenger protein. It is activated when calcium ions bind to it, which allows it to interact with other proteins.

3. **Recognizing its Role**: Upon activation by calcium, calmodulin can regulate various cellular activities, including muscle contraction. It does this by phosphorylating other proteins, such as myosin, which is essential for muscle function.

4. **Locating the Expression**: Calmodulin is expressed in all eukaryotic cells, indicating its fundamental role in cellular signaling and regulation.

5. **Choosing the Correct Option**: Given the options provided:
- Carotene binding protein
- Cadmium binding protein
- Calcium binding protein
- Chlorophyll binding protein

The correct answer is **calcium binding protein**, as calmodulin is specifically known for its ability to bind calcium ions.

**Final Answer**: Calmodulin is a calcium binding protein.

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