Give examples of metabolic poisons that act as enzyme inhibitors.

Potassium Cyanide is an irreversible inhibitor of Cytochrome C Oxidase (involved in the electron transport chain in respiration). Following inhibition of this enzyme, ATP synthesis is stopped. Cells are then dependent on anaerobic respiration leading to an increase in Lactic acid production.

Malonate is a competitive inhibitor of Succinate Dehydrogenase. It has a shape complementary to the active site of succinate dehydrogenase and hence competes with Succinate (original substrate) for binding.