Facilitated diffusion is a method cells use in order to move molecules that cannot readily diffuse across the cell membrane.
Proteins embedded in the cell membrane help molecules diffuse down a concentration gradient from a high concentration to a low concentration.
Protein channels provide a tunnel for molecules to move through the cell membrane.
Facilitated Diffusion is considered passive transport because it requires no energy to occur.
Example substances that use facilitated diffusion in order to cross cell membranes:
sugars, amino acids, ions