Why Cyanide Kills You...

Cyanides (-C≡N) are often found in fruit stones, seeds and bitter almonds in small amounts, but also can be produced by some bacteria and fungi. It is commonly known that most cyanides are highly toxic, but why?


Hydrogen cyanide is an inhibitor of the enzyme cytochrome c oxidase in the fourth complex of the respiratory chain, found in the inner membrane of mitochondria. The binding of a cyanide ion (CN−) and cytochrome c oxidase, stops this enzyme from being able to bind electrons to molecular oxygen, to then bind with protons to make water. Normally the enzyme would translocate H+ ions across the inner membrane in this process, creating a H+ gradient to drive ATP synthase, but this can not be completed because of the presence of the (CN−) on cytochrome c oxidase. As I have described before; ATP synthase catalyses the combination of ADP with inorganic phosphate (like a molecular ferris wheel), creating ATP for molecular energy. Thus now, all aerobic cellular tasks, such as those required in the central nervous system and heart, can not be completed.


When hydrogen cyanide is inhaled, in under 10 minutes, your body will no longer be able to produce the vital energy for life. This will result in death.


Thanks for reading.