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:
Example substances that use facilitated diffusion in order to cross cell membranes:
sugars, amino acids, ions