During aerobic breakdown (respiration) of a molecule of sucrose, the number of CO2 molecules released inside mitochondria but outside TCA cycle will be :-

Options

A. 2
B. 4
C. 6
D. 8

Answer

To solve the question regarding the number of CO2 molecules released during the aerobic breakdown of sucrose inside mitochondria but outside the TCA cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Breakdown of Sucrose**:
- Sucrose is a disaccharide composed of glucose and fructose. When sucrose undergoes aerobic respiration, it breaks down into one molecule of glucose and one molecule of fructose.

2. **Glycolysis**:
- The first step in the aerobic breakdown of glucose and fructose occurs in the cytoplasm through a process called glycolysis.
- Glycolysis converts one molecule of glucose (and one of fructose) into two molecules of pyruvate.

3. **Link Reaction**:
- Each pyruvate molecule then enters the mitochondria where it undergoes the link reaction (also known as the pyruvate decarboxylation).
- During this reaction, each pyruvate is converted into acetyl-CoA, and in the process, one molecule of CO2 is released for each pyruvate.

4. **Calculating CO2 Release from Pyruvate**:
- Since two molecules of pyruvate are produced from the breakdown of one molecule of sucrose, the link reaction will release:
- 2 pyruvate x 1 CO2 per pyruvate = 2 CO2 molecules.

5. **Total CO2 Released**:
- The question specifically asks for the CO2 released **inside the mitochondria but outside the TCA cycle**.
- Therefore, the total number of CO2 molecules released during the breakdown of one molecule of sucrose is **2 CO2 molecules** from the link reaction.

6. **Conclusion**:
- The final answer is that during the aerobic breakdown of one molecule of sucrose, **2 CO2 molecules** are released inside the mitochondria but outside the TCA cycle.

### Final Answer:
**2 CO2 molecules**