The diffusive force for a charged substance depends on its concentration gradient and the electrical potential across the membrane. Which statement about the net movement of the charged substance across the membrane of a cell is CORRECT?
A) The substance can only move from where it is in higher concentration to where it is in lower concentration.
B) Net movement of the substance will continue along the charge gradient when electrochemical equilibrium is reached.
C) The substance will move against its electrical gradient if the opposing concentration gradient is small enough.
D) The substance can move from where it is in higher concentration to where it is in lower concentration if the charge gradient exceeds the opposing concentration gradient.
E) The substance can move along the electrochemical gradient only when the charge difference is very large.

Question

Quizplus · Accepted Answer

The net movement of a charged substance across a membrane is influenced by both its concentration gradient and the electrical potential (charge gradient). If the charge gradient is strong enough, it can drive the movement of the substance against its concentration gradient.

The Diffusive Force for a Charged Substance Depends on Its