Cytochrome which hands over electrons to oxygen during terminal oxidation is

Options

A. Cyt b
B. Cyt a
C. Cyt c
D. Cyt a3

Answer

To solve the question regarding which cytochrome hands over electrons to oxygen during terminal oxidation, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Terminal Oxidation**:
- Terminal oxidation is the final step of the electron transport chain (ETC) in cellular respiration. It involves the transfer of electrons to oxygen, which is the final electron acceptor.

2. **Identifying the Role of Cytochromes**:
- Cytochromes are proteins that play a crucial role in the electron transport chain. They contain heme groups that can undergo oxidation and reduction, facilitating electron transfer.

3. **Analyzing the Options**:
- The options provided are:
- Cytochrome b
- Cytochrome a
- Cytochrome c
- Cytochrome a3

4. **Determining the Function of Each Cytochrome**:
- Cytochrome c is known to transfer electrons to cytochrome a3.
- Cytochrome a3 is specifically involved in transferring electrons to oxygen.

5. **Finalizing the Answer**:
- Since cytochrome a3 is the cytochrome that directly hands over electrons to oxygen during terminal oxidation, the correct answer is **cytochrome a3**.

### Conclusion:
The cytochrome which hands over electrons to oxygen during terminal oxidation is **cytochrome a3**.

---