This does not require a supply of energy because diffusion is a spontaneous process. This occurs when molecules are moved across the cell membrane from an area where they are at a low ...

Diffusion is the net movement of molecules from an area where they are at a higher concentration to areas where they are at a lower concentration. This is due to the random movement of the ...

Cell membranes protect and organize cells. All cells have an outer plasma membrane that regulates not ... which means that some molecules can diffuse across the lipid bilayer but others cannot.