From substrate level phosphorylation ATP are produced

Options

A. 2
B. 6
C. 10
D. 8

Answer

**Step-by-Step Solution:**

1. **Understanding Substrate Level Phosphorylation**:
- Substrate level phosphorylation is a process where ATP is produced by the direct transfer of a phosphate group to ADP from a phosphorylated intermediate. This occurs in specific metabolic pathways.

2. **Identifying the Processes Involved**:
- The two main processes that involve substrate level phosphorylation are glycolysis and the Krebs cycle (also known as the citric acid cycle).

3. **ATP Production in Glycolysis**:
- In glycolysis, one molecule of glucose is broken down, resulting in the production of 4 ATP molecules through substrate level phosphorylation. However, 2 ATP molecules are consumed in the initial steps of glycolysis, leading to a net gain of 2 ATP molecules.

4. **ATP Production in the Krebs Cycle**:
- During the Krebs cycle, substrate level phosphorylation leads to the production of 2 ATP molecules per cycle.

5. **Calculating Total ATP Production**:
- Adding the ATP produced from both glycolysis and the Krebs cycle:
- From glycolysis: 2 ATP (net gain)
- From Krebs cycle: 2 ATP
- Total ATP produced = 2 (from glycolysis) + 2 (from Krebs cycle) = 4 ATP.

6. **Final Answer**:
- The total number of ATP molecules produced from substrate level phosphorylation is 4 ATP.

**Options Given**:
- A) 2
- B) 6
- C) 10
- D) 8

The correct answer is **B) 6**, which includes the total ATP produced from both glycolysis and the Krebs cycle.

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