Carrier proteins differ from channel proteins in their role as gatekeepers of the cell in the sense that carrier proteins bind to the substances they transport across the membrane via facilitated diffusion, whereas channel proteins provide a pore for substances to move across the membrane via facilitated diffusion.
Summarily, Carrier proteins BIND TO THE SUBSTANCES while Channel proteins PROVIDE A PORE FOR SUBSTANCES TO MOVE ACROSS.
They do the same thing that all living and breathing things do! They breathe! When they breathe they are doing the same thing you are doing all day everyday. Inhaling oxygen and exhaling carbon dioxide.
