Inhibition of sugar breakdown due to the presence of `O_(2)` under aerobic condition is called

Options

A. Pasteur effect
B. Warburg effect
C. Crabtree effect
D. Kutusky effect

Answer

To solve the question regarding the inhibition of sugar breakdown due to the presence of oxygen under aerobic conditions, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Context**: The question asks about the inhibition of sugar breakdown when oxygen is present. This indicates a scenario where aerobic conditions are at play.

**Hint**: Consider what happens to sugar breakdown in the presence of oxygen.

2. **Identifying the Process**: In aerobic conditions, the breakdown of sugar (like glucose) typically leads to the production of energy through processes such as glycolysis, followed by the Krebs cycle and oxidative phosphorylation.

**Hint**: Think about the normal metabolic pathways that occur in the presence of oxygen.

3. **Recognizing Inhibition**: The question specifies that sugar breakdown is inhibited by the presence of oxygen. This suggests that under certain conditions, the presence of oxygen prevents the usual breakdown of sugars.

**Hint**: Reflect on how oxygen affects fermentation and anaerobic processes.

4. **Connecting to Anaerobic Respiration**: When oxygen is present, organisms often switch from anaerobic respiration (like fermentation) to aerobic respiration. The inhibition of fermentation by oxygen is a key concept.

**Hint**: Consider the relationship between aerobic and anaerobic respiration and how they interact.

5. **Identifying the Effect**: This phenomenon is known as the "Pasteur effect," which describes the inhibition of fermentation (sugar breakdown) by oxygen.

**Hint**: Remember the name associated with the inhibition of fermentation due to oxygen.

6. **Final Answer**: Therefore, the inhibition of sugar breakdown due to the presence of O2 under aerobic conditions is called the **Pasteur effect**.

### Summary:
The correct answer to the question is the **Pasteur effect**, which describes how the presence of oxygen inhibits the fermentation process, thereby affecting sugar breakdown.