Cu is present in

Options

A. Plasmalemma
B. Plastoquinone
C. Plastocyanin
D. Ferredoxin

Answer

**Step-by-Step Solution:**

1. **Identify the Element**: The question asks about the presence of Cu, which is the chemical symbol for copper.

2. **Understand the Context**: The question relates to the components involved in photosynthesis, specifically during the light reactions.

3. **Recall the Electron Transport Chain**: In the light reactions of photosynthesis, there is an electron transport chain that involves the movement of electrons through various carriers.

4. **Identify the Mobile Electron Carriers**: There are two primary mobile electron carriers involved in this process: plastoquinone and plastocyanin.

5. **Focus on Plastocyanin**: The name "plastocyanin" contains "cyanin," which is derived from the Greek word for blue and is associated with copper (Cu).

6. **Explain the Role of Plastocyanin**: Plastocyanin is a copper-containing protein that plays a crucial role in transporting electrons from the cytochrome b6f complex to photosystem I during the light reactions.

7. **Conclude the Presence of Copper**: Since plastocyanin is specifically identified as a copper-containing protein involved in the electron transport chain of photosynthesis, we can conclude that Cu is present in plastocyanin.

8. **Final Answer**: Therefore, Cu is present in plastocyanin.

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