Question

Glucose from digested food enters intestinal epithelial cells by active transport. Why would intestinal cells use active transport when most body cells use facilitated diffusion?

a) Intestinal cells lack glucose receptors
b) Intestinal cells require energy for absorption
c) Intestinal cells are impermeable to glucose
d) Intestinal cells do not utilize glucose

Answer 1

Intestinal cells use active transport to absorb glucose against its concentration gradient, which requires energy. This mechanism allows for efficient glucose absorption and maintains a low concentration of Na+ ions inside the cell.

Step-by-step explanation:

Intestinal cells use active transport to absorb glucose because it allows them to move glucose against its concentration gradient. Active transport requires energy, which is provided by the expulsion of Na+ ions out of the cell through a Na+, K+, ATPase pump. This process ensures that glucose is absorbed efficiently and maintains a low concentration of Na+ ions inside the cell, compared to the lumen.