Chemiosmotic hypothesis was proposed by

Options

A. Melvin Calvin
B. Hatch and Slack
C. Perter Mitchell
D. Daniel Arnold

Answer

### Step-by-Step Solution

1. **Understanding the Question**: The question asks who proposed the chemiosmotic hypothesis.

2. **Defining Chemiosmotic Hypothesis**: The chemiosmotic hypothesis explains how ATP is synthesized in the mitochondria and chloroplasts. It states that a proton motive force (created by the movement of protons across a membrane) is responsible for ATP synthesis.

3. **Identifying the Options**: The options given are:
- A. Melvin Calvin
- B. Hatchins-Sleck
- C. Peter Mitchell
- D. Daniel Arnott

4. **Analyzing Each Option**:
- **A. Melvin Calvin**: Known for the Calvin cycle (C3 pathway) in photosynthesis, not for the chemiosmotic hypothesis.
- **B. Hatchins-Sleck**: Associated with the C4 pathway in photosynthesis, not related to the chemiosmotic hypothesis.
- **C. Peter Mitchell**: Credited with proposing the chemiosmotic hypothesis, which explains ATP synthesis.
- **D. Daniel Arnott**: Not known for any major contributions related to the chemiosmotic hypothesis.

5. **Conclusion**: Based on the analysis, the correct answer is **C. Peter Mitchell**, as he is the one who proposed the chemiosmotic hypothesis.

### Final Answer
The chemiosmotic hypothesis was proposed by **C. Peter Mitchell**.