Direct ATP yield during Krebs cycle per glucose molecule is

Options

A. 2
B. 8
C. 30
D. 38

Answer

To determine the direct ATP yield during the Krebs cycle (also known as the citric acid cycle or TCA cycle) per glucose molecule, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Glucose Metabolism**:
- When one molecule of glucose undergoes glycolysis, it is converted into two molecules of pyruvate.

2. **Conversion to Acetyl-CoA**:
- Each pyruvate is then converted into one molecule of acetyl-CoA. Therefore, from one glucose molecule, we obtain two acetyl-CoA molecules.

3. **Krebs Cycle Entry**:
- Each acetyl-CoA enters the Krebs cycle.

4. **ATP Yield from Krebs Cycle**:
- For each acetyl-CoA that enters the Krebs cycle, one molecule of ATP (or GTP, which is equivalent to ATP for practical purposes) is produced.

5. **Calculating Total ATP from Two Acetyl-CoA**:
- Since there are two acetyl-CoA molecules from one glucose molecule, the total direct ATP yield from the Krebs cycle would be:
- 1 ATP per acetyl-CoA × 2 acetyl-CoA = 2 ATP.

6. **Final Answer**:
- Therefore, the direct ATP yield during the Krebs cycle per glucose molecule is **2 ATP**.