Which is not found inside the mitochondrion?

Options

A. Citric acid
B. PEP or PEPA
C. Malic acid
D. Ketoglutaric acid

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which substance is not found inside the mitochondrion. We need to analyze the options provided.

2. **Identifying the Options**: The options given are:
- Option 1: Citric acid
- Option 2: Pap (Pyruvate)
- Option 3: Malic acid
- Option 4: Ketoglutaric acid

3. **Analyzing Each Option**:
- **Citric Acid**: This is an intermediate of the TCA (Krebs) cycle, which occurs in the mitochondria. Therefore, citric acid is found in the mitochondrion.
- **Pap (Pyruvate)**: Pyruvate is produced during glycolysis, which occurs in the cytosol. Since glycolysis does not take place in the mitochondria, pyruvate is not found inside the mitochondrion.
- **Malic Acid**: This is also an intermediate of the TCA cycle, which is located in the mitochondria. Thus, malic acid is present in the mitochondrion.
- **Ketoglutaric Acid**: Like citric acid and malic acid, ketoglutaric acid is another intermediate of the TCA cycle and is also found in the mitochondrion.

4. **Conclusion**: Based on the analysis, the substance that is not found inside the mitochondrion is **Pap (Pyruvate)**.

**Final Answer**: Pap (Pyruvate) is not found inside the mitochondrion.

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