Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose- rich food into their glucose- poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells?
A) simple diffusion
B) facilitated diffusion
C) phagocytosis
D) exocytosis
E) active transport pumps

Question

Quizplus · Accepted Answer

Facilitated diffusion is the process by which molecules that cannot directly diffuse through the cell membrane's phospholipid bilayer are assisted by carrier proteins. Since glucose diffuses slowly through artificial phospholipid bilayers but rapidly enters the cells of the small intestine, it suggests that a specific mechanism, like facilitated diffusion, is helping glucose cross the membrane efficiently without the expenditure of energy.

Glucose Diffuses Slowly Through Artificial Phospholipid Bilayers