What is the role of FADH2 in cellular respiration?

FADH2 plays a crucial role in cellular respiration by transferring electrons to the electron transport chain.

Flavin adenine dinucleotide (FADH2) is a vital coenzyme involved in the process of cellular respiration, specifically in the Krebs cycle and the electron transport chain. Cellular respiration is the process by which cells break down glucose and other molecules to produce energy in the form of adenosine triphosphate (ATP). This process involves three main stages: glycolysis, the Krebs cycle, and oxidative phosphorylation.

During the Krebs cycle, FADH2 is produced as a result of the oxidation of succinate to fumarate. This reaction is catalysed by the enzyme succinate dehydrogenase. The FAD molecule accepts two hydrogen atoms, forming FADH2. This is a redox reaction, where FAD is reduced to FADH2.

The role of FADH2 does not end in the Krebs cycle. It is also a crucial player in the final stage of cellular respiration, oxidative phosphorylation. During this stage, FADH2 donates the electrons it gained during the Krebs cycle to the electron transport chain in the inner mitochondrial membrane. As the electrons move down the chain, they release energy which is used to pump protons across the membrane, creating a proton gradient. This gradient drives the synthesis of ATP in a process known as chemiosmosis.

In summary, FADH2 is a key coenzyme in cellular respiration. It is produced during the Krebs cycle and plays a crucial role in transferring electrons to the electron transport chain during oxidative phosphorylation, contributing to the production of ATP, the cell's main energy currency. Without FADH2, the process of cellular respiration would not be as efficient, and cells would not be able to produce as much ATP.