Conversation so far:
where does facilitated diffusion occur in the cell membrane
Facilitated diffusion occurs in the cell body.
what is the definition of diffusion?
Diffusion is the net movement of anything from a region of higher concentration to a region of lower concentration.
How is a cell membrane composed?
Plant cell membranes are rigid walls, and animal cell membranes are lipid bilayers.

Question: what are the bilayers in the membrane
Self-contained rewrite: What are lipid bilayers in cell membranes?