When one glucose molecule is completely oxidised, it changes

Options

A. 36 ADP molecules into 36 ATP molecules
B. 38 ADP molecules into 38 ATP molecules
C. 30 ADP molecules into 30 ATP molecules
D. 32 ADP molecules into 32 ATP molecules

Explanation

**Step-by-Step Solution:**

1. **Understanding Glucose Oxidation**: When one glucose molecule is completely oxidized, it undergoes a series of biochemical processes. The first step is glycolysis, which occurs in the cytoplasm of the cell.

2. **Glycolysis Process**: In glycolysis, one glucose molecule (which consists of six carbon atoms) is converted into two molecules of pyruvic acid (or pyruvate), each containing three carbon atoms. During this process, a net gain of 2 ATP molecules is produced.

3. **Aerobic Respiration**: If oxygen is present, the pyruvic acid enters the Krebs cycle (also known as the citric acid cycle or TCA cycle). Each pyruvate molecule is further oxidized in this cycle.

4. **Krebs Cycle Yield**: For each pyruvate molecule, the Krebs cycle produces:
- 4 NADH (which can be converted to ATP)
- 1 FADH2
- 1 GTP (which is equivalent to 1 ATP)

5. **Calculating ATP from Pyruvate**: Since one glucose molecule yields two pyruvate molecules, we can calculate the total ATP produced:
- From 2 pyruvate molecules:
- 2 x 4 NADH = 8 NADH → 8 x 2.5 ATP = 20 ATP (assuming each NADH yields approximately 2.5 ATP)
- 2 x 1 FADH2 = 2 FADH2 → 2 x 1.5 ATP = 3 ATP (assuming each FADH2 yields approximately 1.5 ATP)
- 2 x 1 GTP = 2 ATP

6. **Total ATP Calculation**: Adding these together:
- From glycolysis: 2 ATP
- From Krebs cycle: 20 ATP (from NADH) + 3 ATP (from FADH2) + 2 ATP (from GTP) = 25 ATP
- Total ATP from one glucose molecule = 2 ATP (glycolysis) + 25 ATP (Krebs cycle) = 27 ATP.

7. **Final Yield**: However, considering the total yield from the complete oxidation of glucose in aerobic respiration is generally cited as 36-38 ATP depending on the efficiency of the electron transport chain and the shuttle mechanisms used to transport NADH into the mitochondria.

8. **Conclusion**: Therefore, the complete oxidation of one glucose molecule typically yields around 36 to 38 ATP molecules.

**Final Answer**: The complete oxidation of one glucose molecule changes to approximately 36 to 38 ATP molecules.

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