Some regions of the plasma membrane, called lipid rafts, have a higher concentration of cholesterol molecules. As a result, these lipid rafts
A) are more fluid than the surrounding membrane.
B) are more rigid than the surrounding membrane.
C) are able to flip from inside to outside.
D) detach from the plasma membrane and clog arteries.
E) have higher rates of lateral diffusion of lipids and proteins into and out of the lipid rafts.

Question

Quizplus · Accepted Answer

Cholesterol molecules make the lipid rafts more rigid than the surrounding membrane due to their ability to pack tightly together and reduce membrane fluidity.

Answer: E 
 The presence of cholesterol in lipid rafts actually increases the rate of lateral diffusion of lipids and proteins into and out of these regions, leading to greater mobility within the membrane.

Some Regions of the Plasma Membrane, Called Lipid Rafts, Have