Describe the effect of cyanide ion CN on oxidative phosphory

Describe the effect of cyanide ion, CN^-, on oxidative phosphorylation and the citric acid cycle. Why is cyanide deadly?

Solution

Cyanide ions inhibit the electron transport chain by binding strongly to the Fe–Cu center in cytochrome c oxidase, preventing the reduction of oxygen. Cytochrome c oxidase is also called Complex IV. Oxygen is the terminal electron acceptor. Oxygen with its 2 extra electrons binds with hydrogen to form water. If oxygen is not present in the mitochondria, elecetrons cannot be removed from the system and the electron transport chain comes to an halt. As a result new ATP cannot be synthesised and the cell would die due to lack of energy.