Hydrogen atoms released at succinate level in Krebs cycle are accepted by

Options

A. FAD
B. NAD
C. ADP
D. FMN

Answer

**Step-by-Step Solution:**

1. **Understanding the Krebs Cycle**: The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions used by all aerobic organisms to generate energy. It involves the conversion of acetyl-CoA into carbon dioxide and energy-carrying molecules.

2. **Identifying the Succinate Level**: In the Krebs cycle, succinate is one of the intermediates. At this stage, succinate undergoes dehydrogenation, which means it loses hydrogen atoms.

3. **Hydrogen Release**: When succinate is converted to fumarate, it releases hydrogen atoms. This process is catalyzed by the enzyme succinate dehydrogenase.

4. **Acceptors of Hydrogen Atoms**: The hydrogen atoms released during the conversion of succinate to fumarate are accepted by a coenzyme. In this case, the coenzyme that accepts these hydrogen atoms is FAD (flavin adenine dinucleotide).

5. **Formation of FADH2**: When FAD accepts the hydrogen atoms, it gets reduced to FADH2. This molecule is an important electron carrier in the electron transport chain, which is essential for ATP production.

6. **Conclusion**: Therefore, the correct answer to the question "Hydrogen atoms released at succinate level in Krebs cycle are accepted by" is FAD.

**Final Answer**: FAD

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