Question

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?

Answer 1

Facilitated diffusion

Step-by-step explanation:

According to the given information, glucose is able to diffuse through the phospholipid bilayers. Both simple and facilitated diffusion transport glucose down its concentration gradient, that is, from the region of higher concentration of glucose to that of its lower concentration.

However, simple diffusion does not use the membrane proteins and is a slow process. Facilitated diffusion of glucose occurs through transmembrane proteins (channels and carriers) that serve to facilitate the transport of glucose across the bilayer at a relatively fast rate. Therefore, the transport of glucose in intestinal cells occurs by facilitated diffusion.