d. It is an active process in which molecules move from a region of lower concentration to one of higher concentration.
e. It requires integral proteins in the cell membrane
19. 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.