Oxidation of one molecule of glucose yields 38 mols of ATP in the proportion of

Options

A. All 38 ATP in mitochondria
B. 8 ATP outside the mitochondria and 30 inside mitochondria.
C. 2 ATP in glycolysis and 36 ATP in Kreb's cycle
D. 2 ATP outside the mitochondria and 36 inside mitochondria.

Answer

To solve the question regarding the oxidation of one molecule of glucose yielding 38 moles of ATP, we will break down the process into several steps:

### Step-by-Step Solution:

1. **Glycolysis**:
- The first step in glucose oxidation occurs in the cytoplasm through glycolysis.
- One molecule of glucose is converted into two molecules of pyruvic acid.
- During glycolysis, a total of 4 ATP are produced, but 2 ATP are consumed in the process.
- Therefore, the net gain from glycolysis is **2 ATP**.

2. **Production of NADH**:
- In addition to ATP, glycolysis also produces 2 NADH molecules.
- Each NADH can yield approximately 3 ATP when it enters the electron transport chain (ETC).
- Thus, from 2 NADH, we can obtain **6 ATP** (2 NADH x 3 ATP/NADH).

3. **Krebs Cycle (Citric Acid Cycle)**:
- The two molecules of pyruvic acid produced from glycolysis enter the mitochondria and undergo the Krebs cycle.
- For each pyruvic acid molecule, the Krebs cycle produces:
- 3 NADH (which will yield 9 ATP)
- 1 FADH2 (which will yield 2 ATP)
- 1 GTP (which is equivalent to 1 ATP)
- Therefore, for one glucose molecule (which produces 2 pyruvic acid), the total yield from the Krebs cycle is:
- 2 pyruvic acid x (3 NADH + 1 FADH2 + 1 GTP) = 2 x (3 NADH + 1 FADH2 + 1 ATP)
- This results in:
- 6 NADH (yielding 18 ATP)
- 2 FADH2 (yielding 4 ATP)
- 2 GTP (yielding 2 ATP)
- Total ATP from Krebs cycle = 18 ATP (from NADH) + 4 ATP (from FADH2) + 2 ATP (from GTP) = **24 ATP**.

4. **Total ATP Calculation**:
- Now, we sum up all the ATP produced:
- From glycolysis: 2 ATP (net) + 6 ATP (from NADH) = 8 ATP
- From Krebs cycle: 24 ATP
- Total ATP = 8 ATP (from glycolysis) + 24 ATP (from Krebs cycle) = **32 ATP**.

5. **Final ATP Yield**:
- The total ATP yield from one molecule of glucose oxidation is **38 ATP**.
- However, the distribution is:
- 2 ATP from glycolysis (in cytoplasm)
- 36 ATP from the Krebs cycle and oxidative phosphorylation (in mitochondria).

### Conclusion:
The correct proportion of ATP produced from the oxidation of one molecule of glucose is:
- **2 ATP in glycolysis and 36 ATP in the Krebs cycle and oxidative phosphorylation**.