part_of part of part of cellular_component membrane respiratory chain complex I Note that this term represents a location and not a function; the activity possessed by this complex is mentioned in the definition for the purpose of describing and distinguishing the complex. The function possessed by this complex is represented by the molecular function term 'NADH dehydrogenase (ubiquinone) activity ; GO:0008137'. NADH-Q oxidoreductase complex GO:0045279 electron transport complex I GO:0045271 NADH dehydrogenase (ubiquinone) complex cellular_component Respiratory chain complex I is an enzyme of the respiratory chain. It consists of several polypeptide chains and is L-shaped, with a horizontal arm lying in the membrane and a vertical arm that projects into the matrix. The electrons of NADH enter the chain at this complex. NADH dehydrogenase complex (ubiquinone)