Which of the following is incorrect regarding oxidative phosphorylation?

Options

A. Oxidation of 1 molecule of NADH gives 3 molecules of ATP.
B. The role of oxygen is limited to the terminal stage of the process.
C. Oxygen acts as the final hydrogen acceptor .
D. Cytochrome c is located towards the inner side (matrix) of the inner mitochondrial membrane.

Answer

To determine which statement regarding oxidative phosphorylation is incorrect, let's analyze each option step by step.

### Step 1: Analyze the first statement
**Statement:** Oxidation of one molecule of NADH gives three molecules of ATP.

**Analysis:**
- This statement is correct. During oxidative phosphorylation, one molecule of NADH typically results in the production of approximately three ATP molecules through the electron transport chain.

### Step 2: Analyze the second statement
**Statement:** The role of oxygen is limited to the terminal stage of the process.

**Analysis:**
- This statement is also correct. In oxidative phosphorylation, oxygen acts as the final electron acceptor at the end of the electron transport chain, which is indeed the terminal stage of the process.

### Step 3: Analyze the third statement
**Statement:** Oxygen acts as the final hydrogen acceptor.

**Analysis:**
- This statement is correct as well. Oxygen accepts electrons and protons (hydrogens) to form water, thus acting as the final hydrogen acceptor in the electron transport chain.

### Step 4: Analyze the fourth statement
**Statement:** Cytochrome c is located towards the inner side, that is, the matrix of the inner mitochondrial membrane.

**Analysis:**
- This statement is incorrect. Cytochrome c is actually located in the intermembrane space of the mitochondria, not in the matrix. It plays a crucial role in the electron transport chain by transferring electrons between Complex III and Complex IV.

### Conclusion
Based on the analysis, the incorrect statement regarding oxidative phosphorylation is:
**Option D:** Cytochrome c is located towards the inner side, that is, the matrix of the inner mitochondrial membrane.

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