Succinate dehydrogenase catalyzes the formation of

Options

A. `FADH_(2) to FAD`
B. `FAD to FADH_(2)`
C. `NAD to NADH+H^(+)`
D. `NADH + H^(+) to FADH_(2)`

Answer

**Step-by-Step Solution:**

1. **Identify the Enzyme and Its Function**: The enzyme in question is succinate dehydrogenase. It plays a crucial role in the Krebs cycle (also known as the citric acid cycle), which is part of cellular respiration.

2. **Understand the Reaction**: Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. This reaction is a dehydrogenation process, meaning that it involves the removal of hydrogen atoms.

3. **Identify the Coenzyme Involved**: During this reaction, the coenzyme FAD (flavin adenine dinucleotide) is reduced to FADH2. This means that FAD accepts electrons and protons (hydrogens) during the conversion of succinate to fumarate.

4. **Energy Production**: The formation of FADH2 is significant because it is an energy carrier. Each molecule of FADH2 produced can lead to the generation of approximately 2 ATP molecules during oxidative phosphorylation in the electron transport chain.

5. **Conclusion**: Therefore, the succinate dehydrogenase catalyzes the formation of FADH2 from FAD during the conversion of succinate to fumarate in the Krebs cycle.

**Final Answer**: Succinate dehydrogenase catalyzes the formation of FADH2.

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