Name the reaction of the citric acid cycle that reduces FAD.

Verified step by step guidance

Identify the citric acid cycle (also known as the Krebs cycle or TCA cycle) as a series of enzymatic reactions that generate energy through the oxidation of acetyl-CoA.

Understand that FAD (flavin adenine dinucleotide) is a coenzyme that gets reduced to FADH₂ during specific reactions in the cycle. Reduction involves the gain of electrons or hydrogen atoms.

Recall that the reaction in the citric acid cycle where FAD is reduced to FADH₂ is catalyzed by the enzyme succinate dehydrogenase.

Recognize that this reaction involves the oxidation of succinate to fumarate, during which FAD acts as the electron acceptor and is reduced to FADH₂.

Conclude that the reaction is named the 'succinate to fumarate' reaction, catalyzed by succinate dehydrogenase, and it is the only step in the citric acid cycle where FAD is reduced instead of NAD⁺.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Citric Acid Cycle

The citric acid cycle, also known as the Krebs cycle, is a series of enzymatic reactions that occur in the mitochondria, playing a crucial role in cellular respiration. It processes acetyl-CoA derived from carbohydrates, fats, and proteins to produce energy carriers like NADH and FADH2, which are essential for ATP production in the electron transport chain.

FAD Reduction

FAD (flavin adenine dinucleotide) is a coenzyme that acts as an electron carrier in various metabolic reactions. In the context of the citric acid cycle, FAD is reduced to FADH2 during the conversion of succinate to fumarate, catalyzed by the enzyme succinate dehydrogenase. This reduction is vital for the transfer of electrons to the electron transport chain, contributing to ATP synthesis.

Succinate Dehydrogenase

Succinate dehydrogenase is an enzyme that catalyzes the oxidation of succinate to fumarate in the citric acid cycle. It is unique as it is embedded in the inner mitochondrial membrane and directly links the citric acid cycle to the electron transport chain. The reaction it catalyzes is the only one in the cycle that produces FADH2, highlighting its importance in energy metabolism.