What is the basic difference between simple
diffusion and facilitated diffusion across a cell membrane?
|In facilitated diffusion, molecules only
move with the aid of a protein in the membrane.
|In simple diffusion, molecules move down
the concentration gradient but in facilitated diffusion molecules
move up the concentration gradient.
|Simple diffusion is passive but
facilitated diffusion is an active process that uses energy.
|Simple diffusion requires molecules to
move through special doorways in the cell membrane.