Changes in membrane potential serve as signals to cells within the body – and can often be a drug target in the treatment of man
y diseases. However, membrane potential is also the target of many toxins that disrupt various cellular processes. Lethal injections, for example, commonly follow a three-step procedure: the first drug is a sedative, the second drug causes muscle paralysis, and the third drug, the one that actually kills, is potassium chloride. What happens to membrane potential when potassium is injected at this very high concentration?
The membrane being semi-permeable means that, not all the things come in and out of the cell, only if it's really needed. The cell works in a gradient way, and that means that, to balance things, the cell will put in it a substance in a very high concentration outside of it, just to balance things. And this would happen to potassium, the cell would put it inside to balance this gradient, and once all sides have the same amount of potassium, it will stop, and the gradient is finally equal.
