Number of oxygen atoms reuqired for oxidation of `2 NADH_(2)` molecules in ETS is

Options

A. 1
B. 2
C. 3
D. 4

Answer

To determine the number of oxygen atoms required for the oxidation of 2 NADH₂ molecules in the Electron Transport System (ETS), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding NADH₂ Oxidation**:
- NADH₂ is a reduced form of NAD⁺, which carries electrons to the Electron Transport Chain (ETC). Each NADH₂ molecule donates electrons to the ETC, which ultimately leads to the reduction of oxygen to water.

2. **Electron Transfer**:
- Each NADH₂ molecule donates 2 electrons to the electron transport chain. Therefore, for 2 NADH₂ molecules, a total of 4 electrons are transferred.

3. **Oxygen's Role**:
- In aerobic respiration, oxygen acts as the final electron acceptor in the electron transport chain. When oxygen accepts electrons, it combines with protons (H⁺ ions) to form water (H₂O).

4. **Calculating Oxygen Requirement**:
- Each molecule of oxygen (O₂) can accept 4 electrons (2 electrons per oxygen atom). Therefore, to completely oxidize 2 NADH₂ molecules (which provide 4 electrons), we need 1 molecule of O₂.

5. **Counting Oxygen Atoms**:
- Since each O₂ molecule contains 2 oxygen atoms, the oxidation of 2 NADH₂ molecules requires 1 O₂ molecule, which corresponds to 2 oxygen atoms.

### Final Answer:
The number of oxygen atoms required for the oxidation of 2 NADH₂ molecules in the ETS is **2 oxygen atoms**.

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