Changes in membrane potential serve as signals to cells within the body – and can often be a drug target in the treatment of many 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 is actually semi-permeable.

Explanation:

    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.

interphase

the period of cell growth when the cell synthesizes new molecules and organelles. the cell is not dividing and it constitutes the majority of the time spent in the cell cycle

prophase

changes occur in the nucleus and cytoplasm. the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still in tact

prometaphase

the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids

metaphase

all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle

anaphase

begins when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell

telophase

the daughter nuclei form at the two poles of a cell

cytokinesis

the division of a cytoplasm to form two separate daughter cells. usually occurs during telophase during mitosis. this and mitosis make up to mitotic (m) phase of the cell cycle