Template:SUIT KCN

Cyanide (usually added as KCN) is a competitive inhibitor of cytochrome c oxidase (CIV). After inhibition the (ROX state) is normally achieved, where Rox is the residual oxygen consumption due to oxidative side reactions estimated either after inhibition or in the absence of endogenous fuel-substrates. Rox is subtracted from oxygen flux as a baseline for all respiratory states, to obtain mitochondrial respiration. In those cells where the cytochrome c oxidase pathway is not active, inhibition with Cyanide may not cause change in the ROUTINE respiration, defined as the respiration in the physiological coupling state. Cyanide inhibition is reversed by pyruvate and high oxygen levels.