In the inner mitochondrial membrane , proton channel is constituted by

Options

A. `F_(0)`
B. `F_(1)`
C. `NADH (H^(+))`
D. Cytochrome oxidase.

Answer

To answer the question "In the inner mitochondrial membrane, proton channel is constituted by...", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Mitochondria Structure**:
- Mitochondria are double-membraned organelles found in eukaryotic cells. They have an outer membrane and a highly folded inner membrane.

2. **Identifying Key Features**:
- The inner mitochondrial membrane contains structures known as cristae, which increase the surface area for biochemical reactions.

3. **Proton Channels in Mitochondria**:
- Within the inner mitochondrial membrane, there are specific complexes that facilitate the transport of protons (H+ ions). These channels are crucial for the process of oxidative phosphorylation.

4. **F0F1 ATP Synthase**:
- The proton channel is constituted by the F0 portion of the ATP synthase complex, often referred to as F0F1 ATP synthase. The F0 component forms a channel through which protons flow back into the mitochondrial matrix from the intermembrane space.

5. **Role of Proton Gradient**:
- The movement of protons through these channels is driven by a proton gradient established by the electron transport chain. This flow of protons is essential for the synthesis of ATP from ADP and inorganic phosphate.

6. **Conclusion**:
- Therefore, the answer to the question is that the proton channel in the inner mitochondrial membrane is constituted by the F0 portion of the ATP synthase complex.

### Final Answer:
In the inner mitochondrial membrane, the proton channel is constituted by the F0 portion of the ATP synthase complex.

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