Question

How do carbon monoxide and cyanide cause death?

Answer 1

Carbon monoxide `(CO)` and cyanide `(CN^-)` both react with oxygen in our red blood cells. This means that the oxygen is not transported to all parts of the body, and therefore we cannot breathe and respire.

Answer 2

Both prevent the cells from being able to use oxygen, but they don't react with oxygen.

Explanation:

Carbon monoxide binds with the iron in hemoglobin preferentially to oxygen. This prevents oxygen from binding to hemoglobin and being carried to cells for aerobic cellular respiration. Without oxygen, aerobic cellular respiration stops, preventing aerobic cellular respiration from producing ATP. Without ATP, the cells will die.

The cyanide anion, `"CN"^(-)` combines with the iron atom in the enzyme cytochrome C oxidase in the mitochondria of cells. This prevents the enzyme from transporting electrons to oxygen in the electron transport chain of aerobic cellular respiration, which effectively stops aerobic cellular respiration, so no ATP will be produced, and the cells will die.