Compared with other cell components (organelles, cell membrane or nucleus), the mitochondria would be the only fraction that would :

Options

A. form an electrochemical gradient across a membrane
B. use significant amounts of oxygen
C. use a chemiosmotic complex to produce ATP
D. release protons `(H^(+) ) `

Explanation

### Step-by-Step Solution

1. **Understanding Mitochondria**:
- Mitochondria are membrane-bound organelles known as the "powerhouse of the cell" because they are primarily responsible for producing ATP (adenosine triphosphate) through cellular respiration.

2. **Cellular Respiration Process**:
- The process begins with glycolysis, where glucose is broken down into pyruvate.
- Pyruvate is then converted into acetyl coenzyme A, which enters the Krebs cycle (also known as the citric acid cycle) within the mitochondria.

3. **Krebs Cycle**:
- During the Krebs cycle, energy carriers NADH and FADH2 are produced. These carriers are essential for the next stage of cellular respiration.

4. **Electron Transport Chain (ETS)**:
- NADH and FADH2 donate electrons to the electron transport chain, leading to the production of ATP through oxidative phosphorylation.
- Oxygen is used as the final electron acceptor in this process, forming water.

5. **Formation of Electrochemical Gradient**:
- The movement of electrons through the ETS creates a proton (H+) gradient across the mitochondrial membrane, which is crucial for ATP production.

6. **Evaluating the Options**:
- **Option 1**: Form an electrochemical gradient across the membrane - **Incorrect** (Mitochondria do not primarily form this gradient through active transport).
- **Option 2**: Use significant amounts of oxygen - **Correct** (Oxygen is essential for the electron transport chain).
- **Option 3**: Use a chemoosmotic complex to produce ATP - **Correct** (The process of ATP production is linked to the chemiosmotic gradient).
- **Option 4**: Release protons - **Incorrect** (Protons are released but are quickly utilized in the formation of water).

7. **Conclusion**:
- The correct options are that mitochondria use significant amounts of oxygen and utilize a chemoosmotic complex to produce ATP.