In cellular respiration, oxygen is used as the final receptor of
Nitrogen
Iron
Carbon
Hydrogen

Options

A. Nitrogen
B. Iron
C. Carbon
D. Hydrogen

Answer

To solve the question "In cellular respiration, oxygen is used as the final receptor of," we need to analyze the process of cellular respiration and understand the role of oxygen in it.

### Step-by-Step Solution:

1. **Understanding Cellular Respiration**:
- Cellular respiration is a biochemical process that occurs in cells to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. It involves several stages, including glycolysis, the Krebs cycle (or citric acid cycle), and the electron transport chain (ETC).

**Hint**: Remember that cellular respiration primarily occurs in the mitochondria of cells.

2. **Role of the Electron Transport Chain (ETC)**:
- The final step of cellular respiration is the electron transport chain (ETC). During this process, electrons are transferred through a series of proteins and other molecules embedded in the inner mitochondrial membrane.

**Hint**: Focus on the sequence of electron transfer in the ETC and how it leads to ATP production.

3. **Final Electron Acceptor**:
- In the ETC, the electrons produced from NADH and FADH2 (from earlier stages of respiration) are passed along the chain. The final electron acceptor in this chain is oxygen. This means that oxygen receives the electrons at the end of the chain.

**Hint**: Think about what happens to the electrons at the end of the ETC and what they combine with.

4. **Formation of Water**:
- When oxygen accepts the electrons, it also combines with hydrogen ions (protons) to form water (H2O). This reaction is crucial as it helps maintain the flow of electrons through the ETC.

**Hint**: Consider the relationship between oxygen and hydrogen in this context.

5. **Conclusion**:
- Since oxygen is the final electron acceptor in the process of cellular respiration, and it combines with hydrogen ions, we conclude that in cellular respiration, oxygen is used as the final receptor of **hydrogen**.

**Final Answer**: Option D: Hydrogen.