Ions Diffuse Across Membranes Through Specific Ion Channels

Question

Ions diffuse across membranes through specific ion channels
A)down their chemical gradients.
B)down their concentration gradients.
C)down the electrical gradients.
D)down their electrochemical gradients.
E)down the osmotic potential gradients.

Accepted Answer

Ion channels allow ions to move down their electrochemical gradient, which is the combined chemical and electrical gradient. The chemical gradient is due to the difference in ion concentration on either side of the membrane, while the electrical gradient is due to the difference in charge across the membrane. Therefore, ions will move from a region of higher electrochemical potential to a region of lower electrochemical potential (i.e. down their electrochemical gradient) through specific ion channels.