Succinate is oxidised to fumarate in Krebs cycle by

Options

A. Removal of hydrogen
B. Loss of electrons
C. Addition of oxygen
D. Removal of oxygen

Answer

**Step-by-Step Solution:**

1. **Identify the Reaction in the Krebs Cycle**: The question asks about the oxidation of succinate to fumarate in the Krebs cycle. This reaction is a part of the metabolic pathway that occurs in the mitochondrial matrix.

2. **Understand the Process of Oxidation**: The conversion of succinate to fumarate involves the removal of hydrogen atoms from succinate. This process is known as dehydrogenation.

3. **Identify the Enzyme Involved**: The enzyme responsible for this reaction is called succinate dehydrogenase. This enzyme catalyzes the dehydrogenation of succinate, facilitating its conversion to fumarate.

4. **Recognize the Coenzyme Used**: During this reaction, the coenzyme flavin adenine dinucleotide (FAD) is reduced to FADH2. This is an important step because FADH2 will later enter the electron transport chain (ETC) to produce ATP.

5. **Conclusion**: Therefore, the correct answer to the question is that succinate is oxidized to fumarate by the enzyme succinate dehydrogenase.

**Final Answer**: Succinate is oxidized to fumarate in the Krebs cycle by succinate dehydrogenase.

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