What role does FADH2 play in cellular respiration?

FADH2 serves as an essential energy carrier in cellular respiration, particularly during the electron transport chain phase. After being produced in the Krebs cycle (also known as the citric acid cycle), FADH2 donates electrons to the electron transport chain, where these electrons are passed through a series of protein complexes. This transfer of electrons allows for proton pumps to actively transport protons across the inner mitochondrial membrane, creating a proton gradient. As protons flow back across the membrane through ATP synthase, ATP is synthesized.

Understanding the role of FADH2 underscores the importance of oxidation-reduction reactions in cellular respiration, where the breakdown of nutrients ultimately leads to energy production in the form of ATP. This highlights FADH2's specific function in linking metabolic pathways to the energy-generating processes in the cell.