Oxidation of one molecule of glucose in results in the production of

Options

A. 36ATP molecules
B. 38 ATP molecules
C. 3 ATP molecules
D. 15 ATP molecules

Answer

To determine the total ATP produced from the oxidation of one molecule of glucose, we can break down the process into several steps:

### Step-by-Step Solution:

1. **Glycolysis**:
- The first step in the oxidation of glucose is glycolysis, which occurs in the cytoplasm.
- During glycolysis, one molecule of glucose is converted into two molecules of pyruvate.
- This process produces a net gain of **2 ATP** and **2 NADH** (which can be converted to ATP later).

2. **Conversion of Pyruvate to Acetyl-CoA**:
- Each pyruvate molecule is then converted into acetyl-CoA in the mitochondria.
- This conversion also produces **1 NADH** per pyruvate. Since there are two pyruvate molecules, this results in **2 NADH** total.
- The conversion does not produce any additional ATP directly.

3. **Citric Acid Cycle (Krebs Cycle)**:
- Each acetyl-CoA enters the citric acid cycle, which occurs in the mitochondrial matrix.
- For each acetyl-CoA, the cycle produces **3 NADH**, **1 FADH2**, and **1 ATP** (or GTP).
- Since there are two acetyl-CoA molecules from one glucose, the total yield from the citric acid cycle is:
- **6 NADH** (3 per acetyl-CoA)
- **2 FADH2** (1 per acetyl-CoA)
- **2 ATP** (1 per acetyl-CoA)

4. **Total ATP Calculation**:
- Now, we need to convert the NADH and FADH2 produced into ATP:
- Each NADH can yield approximately **2.5 ATP** when it enters the electron transport chain.
- Each FADH2 can yield approximately **1.5 ATP**.
- From glycolysis:
- 2 NADH → 2 x 2.5 = **5 ATP**
- From the conversion of pyruvate to acetyl-CoA:
- 2 NADH → 2 x 2.5 = **5 ATP**
- From the citric acid cycle:
- 6 NADH → 6 x 2.5 = **15 ATP**
- 2 FADH2 → 2 x 1.5 = **3 ATP**
- 2 ATP from the cycle itself.

5. **Total ATP Produced**:
- Adding all the ATP produced:
- Glycolysis: 2 ATP + 5 ATP (from NADH) = **7 ATP**
- Pyruvate to Acetyl-CoA: 5 ATP (from NADH) = **5 ATP**
- Citric Acid Cycle: 2 ATP + 15 ATP (from NADH) + 3 ATP (from FADH2) = **20 ATP**
- Total = 7 + 5 + 20 = **32 ATP**

6. **Final Result**:
- The total ATP yield from the complete oxidation of one molecule of glucose is **approximately 38 ATP** (considering some variations and efficiencies in the process).