AP BIOLOGY

Detailed explanation-1: -However, facilitated diffusion differs from passive diffusion in that the transported molecules do not dissolve in the phospholipid bilayer. Instead, their passage is mediated by proteins that enable the transported molecules to cross the membrane without directly interacting with its hydrophobic interior.

Detailed explanation-2: -The difference is how the substance gets through the cell membrane. In simple diffusion, the substance passes between the phospholipids; in facilitated diffusion there are a specialized membrane channels.

Detailed explanation-3: -Facilitated diffusion occurs along a concentration gradient from high concentration to low concentration and does not require energy, while active transport from low concentration to high concentration occurs against the concentration gradient and requires energy.

Detailed explanation-4: -Simple passive diffusion occurs when small molecules pass through the lipid bilayer of a cell membrane. Facilitated diffusion depends on carrier proteins imbedded in the membrane to allow specific substances to pass through, that might not be able to diffuse through the cell membrane.