Question

1. cyanide ion (CN-) inhibits the electron transport chain. Cyanide (though deadly) does not lead to production of excessive heat, unlike uncouplers. Explain why.

Answer 1

In a nutshell, cyanide prevents cells from using oxygen to make energy molecules and act as a poision.

The cyanide ion, CN-, binds to the iron atom in cytochrome C oxidase in the mitochondria of cells. It acts as an irreversible enzyme inhibitor, preventing cytochrome C oxidase from doing its job, which is to transport electrons to oxygen in the electron transport chain of aerobic cellular respiration. Without the ability to use oxygen, mitochondria can't produce the energy carrier adenosine triphosphate (ATP) i.e No ATP, no heat and no energy. Tissues that require this form of energy, such as heart muscle cells and nerve cells, quickly expend all their energy and start to die.