AP BIOLOGY

Detailed explanation-1: -In facilitated transport, also called facilitated diffusion, material moves across the plasma membrane with the assistance of transmembrane proteins down a concentration gradient (from high to low concentration) without the expenditure of cellular energy.

Detailed explanation-2: -Facilitated diffusion is the passive movement of molecules along the concentration gradient. It is a selective process, i.e., the membrane allows only selective molecules and ions to pass through it. It, however, prevents other molecules from passing through the membrane.

Detailed explanation-3: -In facilitated diffusion, substances move into or out of cells down their concentration gradient through protein channels in the cell membrane.

Detailed explanation-4: -Facilitated Diffusion Requires Membrane Carrier Proteins Facilitated diffusion is also calledcarrier-mediated diffusion because a substance transported in this manner diffuses through the membrane with the help of a specific carrier protein.

Detailed explanation-5: -Facilitated diffusion does not need any energy for the movement of molecules as they move from higher concentration to lower concentration gradient.