Water Passes Quickly Through Cell Membranes Because

Question

Water passes quickly through cell membranes because
A)the bilayer is hydrophilic.
B)it moves through hydrophobic channels.
C)water movement is tied to ATP hydrolysis.
D)it is a small, polar, charged molecule.
E)it moves through aquaporins in the membrane.

Accepted Answer

Water passes quickly through cell membranes because it moves through aquaporins in the membrane, which are specific protein channels that allow the facilitated diffusion of water molecules. The aquaporin pores are too narrow for larger polar molecules to pass through, which is why water can move quickly and selectively through these channels.