The relative concentration of each in the plasma membrane is partly regulated by the:

ion channels

Explanation:

The plasma membrane plays a critical role in regulating and maintaining ionic potential inside the cell, relative to ionic concentration present outside the cell. The ion channels are specific, in that they only recognize and allow particular ions to pass through and block the rest. Their opening and closing depends on the ionic potential during that time period.

this transfer is call conjunction

you can have just about every answer you can think of