Pasteur effect is due to

Options

A. Change from aerobic to anaerobic
B. Providing oxygen to anaerobically respiring structures
C. Rapid utilisation of ATP
D. Nonsynthesis of ATP

Answer

**Step-by-Step Solution:**

1. **Understanding the Pasteur Effect**: The Pasteur effect refers to the phenomenon where the presence of oxygen inhibits the fermentation process in organisms that typically rely on anaerobic respiration, such as yeast.

2. **Identifying the Process**: Fermentation is an anaerobic process, meaning it occurs in the absence of oxygen. When oxygen is introduced into a system that is undergoing fermentation, it can lead to a decrease or complete stoppage of the fermentation process.

3. **Analyzing the Options**:
- **Option 1**: "Change from aerobic to anaerobic" - This is incorrect because the Pasteur effect is about the change from anaerobic to aerobic conditions.
- **Option 2**: "Providing oxygen to anaerobically respiring structures" - This option is correct. When oxygen is provided to structures that typically respire anaerobically, it leads to the Pasteur effect.
- **Option 3**: "Rapid utilization of ATP" - This is incorrect because the Pasteur effect does not involve rapid ATP utilization; rather, it involves inhibition of fermentation.

4. **Conclusion**: The correct answer is that the Pasteur effect is due to the providing of oxygen to anaerobically respiring structures, which inhibits the fermentation process.

**Final Answer**: The Pasteur effect is due to providing oxygen to anaerobically respiring structures.

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