Total number of ATP produced when one molecule of G3P, participates in aerobic respiration is

Options

A. 6
B. 10
C. 2
D. 8

Answer

To determine the total number of ATP produced when one molecule of G3P (glyceraldehyde-3-phosphate) participates in aerobic respiration, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Glycolysis**:
- Glycolysis is the first step in aerobic respiration where glucose is converted into pyruvate. It consists of two phases: the preparatory phase and the payoff phase.

2. **Preparatory Phase**:
- In the preparatory phase, glucose is converted into two molecules of G3P. During this phase, 2 ATP molecules are consumed.

3. **Payoff Phase**:
- In the payoff phase, each molecule of G3P is converted into pyruvate. During this conversion, several energy carriers are produced:
- Each G3P produces 2 NADH molecules.
- Additionally, 2 ATP molecules are generated directly from the conversion of G3P to pyruvate.

4. **Calculating ATP from One G3P**:
- Since one molecule of glucose yields two molecules of G3P, we need to consider the ATP yield from just one G3P:
- From one G3P, we get 2 ATP (from the payoff phase).
- Additionally, we also need to account for the NADH produced. Each NADH can be converted to approximately 2.5 ATP in the electron transport chain. Therefore, 2 NADH from one G3P would yield about 5 ATP.

5. **Total ATP Calculation**:
- Total ATP produced from one G3P:
- ATP from G3P conversion: 2 ATP
- ATP from NADH: 5 ATP
- Therefore, total ATP = 2 ATP + 5 ATP = 7 ATP.

### Final Answer:
The total number of ATP produced when one molecule of G3P participates in aerobic respiration is **7 ATP**.