Cyanide, a deadly compound found in bitter almonds and apple seeds, consists of simply two atoms (Carbon and Nitrogen) bonded together as a unit. Cyanide is typically found in ionic compounds where it is bonded to one other positive ion (a cation); hydrogen cyanide and potassium cyanide are notorious examples.
The toxicity of cyanide depends on how easily the bond between the cyanide unit and the cation can be broken. For instance, in hydrogen cyanide, the bond between the H+ and the cyanide unit are easily broken so hydrogen cyanide is extremely toxic.
When cyanide enters the bloodstream, it attaches to the iron in haemoglobin – displacing oxygen. Once bonded to haemoglobin, cyanide can travel rapidly around the body and reach the mitochondria of the cells. Within the mitochondria, cyanide can bind irreversibly to cytochrome c oxidase (an important respiration enzyme) – preventing energy from being released into the cell and, eventually, killing the cell.
Curiosity Killed The Cation 