Iron-prophyrin protein complex occurs in

Options

A. Cytochrome
B. Chlorophyll
C. Phytochrome
D. Both A and B

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks where the iron-prophyrin protein complex occurs. The options provided are cytochrome, chlorophyll, phytochrome, and both A and B.

2. **Identifying Key Concepts:**
- The iron-prophyrin complex is a crucial component in various biological processes, particularly in respiration and photosynthesis.
- Cytochromes are known to contain iron in a porphyrin ring structure and are involved in the electron transport system (ETS).

3. **Analyzing Each Option:**
- **Cytochrome:** This is a protein that contains an iron-prophyrin complex and functions as an electron carrier in the electron transport chain during cellular respiration.
- **Chlorophyll:** This is the green pigment in plants that absorbs light for photosynthesis but does not primarily function as an electron carrier in respiration.
- **Phytochrome:** This is a photoreceptor involved in plant responses to light but does not contain an iron-prophyrin complex.
- **Both A and B:** This option suggests that both cytochrome and chlorophyll contain the iron-prophyrin complex, which is incorrect since chlorophyll does not.

4. **Conclusion:**
After analyzing the options, it is clear that the iron-prophyrin protein complex occurs in **cytochrome**. Therefore, the correct answer is the first option.

**Final Answer:**
The iron-prophyrin protein complex occurs in **cytochrome**.

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