So one end of the molecule is afraid of the water, and one end loves being in the water. Millions of these molecules line up together to form a cell membrane. Throughout the membrane are proteins stuck inside the membrane. These proteins cross the bilayer and make the holes that let ions and molecules in and out of the cell. Facilitated means helped.
Diffusion means moving from one area to another.
So facilitated diffusion is a procedure where an ion is helped across the membrane. Andrew Rader Studios, All rights reserved.