Oxidative phosphorylation is production of

Options

A. ATP in photosynthesis
B. NADH in photosynthesis
C. ATP in respiration
D. NADH in respiration

Answer

### Step-by-Step Solution:

1. **Understanding Oxidative Phosphorylation**:
- Oxidative phosphorylation is a biochemical process that occurs in the mitochondria of cells. It is primarily responsible for the production of ATP (adenosine triphosphate), which is the energy currency of the cell.

2. **Role of Oxygen**:
- The term "oxidative" indicates that oxygen is utilized in this process. In oxidative phosphorylation, oxygen acts as the final electron acceptor in the electron transport chain (ETC).

3. **Formation of ATP**:
- The process involves the transfer of electrons through a series of protein complexes in the inner mitochondrial membrane, leading to the pumping of protons (H+ ions) into the intermembrane space. This creates a proton gradient.

4. **ATP Synthesis**:
- The protons then flow back into the mitochondrial matrix through ATP synthase, a protein complex that synthesizes ATP from ADP and inorganic phosphate (Pi). This process is known as chemiosmosis.

5. **Identifying the Correct Answer**:
- The question asks what oxidative phosphorylation produces. Among the options provided:
- Option 1: Formation of ATP in photosynthesis (this is called photophosphorylation).
- Option 2: NADH in photosynthesis (related to the Z scheme).
- Option 3: ATP in respiration (this is correct as it refers to oxidative phosphorylation).
- Option 4: Formation of NADH in respiration (this is incorrect as it refers to a different process).
- Therefore, the correct answer is **Option 3: ATP in respiration**.