Transport of Molecules

Facilitated diffusion is the process of spontaneous passive transport of molecules or ions across a biological membrane via specific transmembrane integral proteins.

Diffusion is the net movement of anything from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in concentration. The concept of diffusion is widely used in many fields, including physics, chemistry, biology, sociology, economics, and finance.

Osmosis is the spontaneous net movement or diffusion of solvent molecules through a selectively permeable membrane from a region of high water potential to a region of low water potential, in the direction that tends to equalize the solute concentrations on the two sides.

Active is the movement of molecules or ions against a concentration gradient (from an area of lower to higher concentration). While passive transport is the movement of molecules or ions from an area of higher to lower concentration.