. "\"A protein complex located in the mitochondrial inner membrane that forms part of the mitochondrial respiratory chain. Contains the four polypeptide subunits of succinate dehydrogenase, flavin-adenine dinucleotide and iron-sulfur. Catalyzes the oxidation of succinate by ubiquinone. Connects the TCA cycle with the respiratory chain.\" [GOC:mtg_sensu, ISBN:0198547684]" . . "mitochondrial respiratory chain complex II" . "mitochondrial fumarate reductase complex" . . . .