In respiration, the final acceptor of protons is

Options

A. `NAD
B. oxygen
C. FAD
D. UQ

Answer

**Step-by-Step Solution:**

1. **Understanding Respiration**: Begin by recognizing that respiration is a metabolic process where cells convert nutrients into energy. The main stages of respiration include glycolysis, the Krebs cycle, and the electron transport chain (ETC).

2. **Identifying the Electron Transport Chain (ETC)**: The ETC is the final stage of cellular respiration, where electrons are transferred through a series of protein complexes located in the inner mitochondrial membrane.

3. **Role of Electron Carriers**: During the Krebs cycle, electron carriers such as NADH and FADH2 are produced. These carriers transport electrons to the ETC.

4. **Proton Movement**: As electrons move through the ETC, protons (H+) are pumped across the mitochondrial membrane, creating a proton gradient.

5. **Final Electron Acceptor**: The final acceptor of electrons in the ETC is oxygen. Oxygen combines with electrons and protons to form water. This reaction is crucial for the continuation of the electron transport chain.

6. **Importance of Oxygen**: Without oxygen, the electron transport chain cannot function, leading to a halt in ATP production. This highlights the essential role of oxygen in aerobic respiration.

7. **Conclusion**: Therefore, the final acceptor of protons in respiration is oxygen.

**Final Answer**: The final acceptor of protons in respiration is **Oxygen**.

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