Diffusion refers to the passive movement of particles (molecules or ions) from an area of higher concentration to an area of lower concentration. It occurs due to random molecular motion and does not require energy input from the cell.
Facilitated diffusion is a type of passive transport where specific transmembrane proteins assist in transporting larger or charged molecules across the cell membrane along their concentration gradient.
Equilibrium: Equilibrium refers to a state where there is no net movement of particles because concentrations are equal on both sides of a barrier. In diffusion, equilibrium occurs when there is no overall change in concentration over time.
These integral membrane proteins form channels across the cell membrane allowing for selective passage of specific ions or molecules based on size, shape, or charge.