Which factor MOST significantly determines the direction in which an ion moves through an ion channel in a membrane?

Question

Quizplus · Accepted Answer

The most significant factor determining the direction in which an ion moves through an ion channel in a membrane is the electrochemical gradient across the membrane. This gradient consists of both a chemical gradient (difference in concentration of the ion on either side of the membrane) and an electrical gradient (difference in charge across the membrane). The ion will move down its electrochemical gradient, from an area of higher concentration/electrical potential to an area of lower concentration/electrical potential. The size and shape of the channel and the ion selectivity of the channel can influence the rate and specificity of ion movement, but they do not override the electrochemical gradient as the primary determinant of direction.

Which Factor MOST Significantly Determines the Direction in Which an Ion