How many ATP molecules are relaeased when 1 molecule of glucose is oxidized in our liver cells ?

Options

A. 36
B. 38
C. 2
D. 8

Answer

To determine how many ATP molecules are released when one molecule of glucose is oxidized in liver cells, we can break down the process into several key steps:

### Step-by-Step Solution:

1. **Glycolysis**:
- The first step in glucose oxidation is glycolysis, which occurs in the cytoplasm of the cell. During glycolysis, one molecule of glucose (6 carbons) is broken down into two molecules of pyruvate (3 carbons each).
- In this process, a net gain of **2 ATP molecules** is produced.

2. **Krebs Cycle (Citric Acid Cycle)**:
- After glycolysis, if oxygen is present, the pyruvate enters the mitochondria and is converted into acetyl-CoA, which then enters the Krebs cycle.
- In the Krebs cycle, for each molecule of glucose (which produces two molecules of acetyl-CoA), a total of **2 ATP molecules** are produced.

3. **Electron Transport Chain (ETC)**:
- The next step is the electron transport chain, which occurs in the inner mitochondrial membrane. Here, the electrons from NADH and FADH2 (produced in glycolysis and the Krebs cycle) are transferred through a series of protein complexes.
- This process generates a significant amount of ATP. For each molecule of glucose, a total of **34 ATP molecules** are produced during the electron transport chain.

4. **Total ATP Calculation**:
- Now, we can add up all the ATP produced from each stage:
- Glycolysis: 2 ATP
- Krebs Cycle: 2 ATP
- Electron Transport Chain: 34 ATP
- Total ATP = 2 + 2 + 34 = **38 ATP molecules**.

### Final Answer:
When one molecule of glucose is oxidized in liver cells, a total of **38 ATP molecules** are produced.

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