respiratory chain complex II (succinate dehydrogenase) https://github.com/geneontology/go-ontology/issues/27253 https://github.com/geneontology/go-ontology/issues/28017 electron transport complex II A part of the respiratory chain, containing 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. GO:0045273 cellular_component membrane protein complex respiratory chain complex oxidoreductase complex