Which of the following is a copper -containing protein acting as a mobile electron carrier electron in thylakoid membran ?

Options

A. Plastocyanin
B. Plastoquinone
C. Pheophytin
D. Cytochrome `b_(6)`

Answer

To solve the question of which copper-containing protein acts as a mobile electron carrier in the thylakoid membrane, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**: The question is asking about a specific type of protein that contains copper and functions as a mobile electron carrier within the thylakoid membrane of chloroplasts during photosynthesis.

2. **Identify the Options**: The options given are:
- A) Plastocyanin
- B) Plastoquinone
- C) Pheophytin
- D) Cytochrome b6

3. **Recall the Function of Each Option**:
- **Plastocyanin**: A copper-containing protein that transfers electrons from the cytochrome b6f complex to Photosystem I.
- **Plastoquinone**: A mobile electron carrier that transports electrons from Photosystem II to the cytochrome b6f complex, but it does not contain copper.
- **Pheophytin**: A pigment that acts as an electron carrier but does not contain copper.
- **Cytochrome b6**: A component of the cytochrome b6f complex, but it is not a mobile electron carrier and does not contain copper.

4. **Determine the Correct Answer**: Since plastocyanin is the only option that is a copper-containing protein and acts as a mobile electron carrier, the correct answer is:
- **A) Plastocyanin**

5. **Conclusion**: Therefore, the answer to the question is plastocyanin, as it is the copper-containing protein that functions as a mobile electron carrier in the thylakoid membrane.