The Primary Function of Polysaccharides Attached to the Glycoproteins and Glycolipids

The primary function of polysaccharides attached to the glycoproteins and glycolipids of animal cell membranes is

A) to facilitate diffusion of molecules down their concentration gradients.
B) to actively transport molecules against their concentration gradients.
C) to maintain the integrity of a fluid mosaic membrane.
D) to maintain membrane fluidity at low temperatures.
E) to mediate cell-to-cell recognition.