Electrons taking part in electron transport system inside mitochondira come from

Options

A. Pyruvate
B. `NADH(H^(+))`
C. `FADH_(2)`
D. Both B and C

Answer

**Step-by-Step Solution:**

1. **Understanding the Electron Transport System (ETS)**:
- The electron transport system is located in the inner membrane of the mitochondria. It consists of a series of proteins and organic molecules that facilitate the transfer of electrons.

2. **Sources of Electrons**:
- The electrons that participate in the electron transport chain primarily come from two key molecules: NADH and FADH2.

3. **Production of NADH and FADH2**:
- These molecules are generated during various metabolic processes:
- **Glycolysis**: The breakdown of glucose into pyruvate, which produces NADH.
- **Pyruvate Oxidation**: The conversion of pyruvate into acetyl-CoA also produces NADH.
- **Citric Acid Cycle (TCA Cycle)**: This cycle further produces both NADH and FADH2 as it processes acetyl-CoA.

4. **Conclusion**:
- Therefore, the electrons that participate in the electron transport system inside mitochondria come from both NADH and FADH2. Hence, the correct answer is "both B and C".

**Final Answer**: Electrons taking part in the electron transport system inside mitochondria come from both NADH and FADH2 (both B and C).

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