Concept 4 Review

Comparing Facilitated Diffusion and Active Transport

Transport of solutes across cell membranes by protein carriers can occur in one of two ways:

To visually compare facilitated diffusion and active transport, click the "Play" buttons.

The transport process a cell uses depends on its specific needs. For example, red blood cells rely on facilitated diffusion to move glucose across membranes, whereas intestinal epithelial cells use active transport to take in glucose from the gut. Facilitated diffusion is effective for red blood cells because the concentration of glucose in the blood is stable and higher than the cellular concentration. On the other hand, active transport is needed in the gut because there are large fluctuations of glucose concentration as a result of eating.