Ion Channels in Cell Membranes

Question

Ion channels  in cell membranes
A)are nonspecific.
B)are not affected by differences in electrical potential across the membrane.
C)may open in response to binding a ligand.
D)only allow ions to move from the extracellular fluid into the cell.
E)only allow ions to move from the intracellular fluid out of the cell.

Accepted Answer

Ion channels may open in response to binding a ligand, such as a neurotransmitter or hormone, which causes a conformational change and allows ions to pass through. Ion channels can also be specific for certain ions and can be affected by the electrical potential across the membrane, which can result in changes in ion flux. Ion channels can allow ions to move in both directions across the membrane, depending on the concentration gradient and electrical potential. Therefore, options A, B, D, and E are incorrect.