 Flavin adenine dinucleotide

Flavin adenine dinucleotide is a redox coenzyme with a flavin ring system linked to an adenine-containing nucleotide unit. Reduction of the flavin gives FADH2.

In succinate dehydrogenase, an enzyme-bound flavin accepts reducing equivalents during conversion of succinate to fumarate. The flavin is reoxidized through the respiratory electron-transfer machinery, connecting a carbon-metabolism reaction with the mitochondrial respiratory chain.