The electron flow in cytochrome C oxidase can be blocked by

Inhibitors of Electron transport chain (Respiratory chain) Complex I :- Barbiturates (amobarbital), piercidin A, rotenone, chlorpromazine, guanithidine. Complex II Carboxin, TTFA, malonate. Complex HI Dimercaprol, BAL, actinomycin A, Naphthyloquinone. Complex IV (cytochrome c oxidase) :- Carbon monoxide (CO), cyanide (CN),H2S, azide (N3-)