A cellular physiologic passive process through a semipermeable membrane where substances move down a concentration gradient from areas of high solute concentration to areas of low solute concentration, by dissolving in the lipid portion of the cellular membrane.
Influenced by the solubility of molecules in lipids, temperature and the concentration gradient.
Lipid soluble substances have greater diffusion through the lipid layer portions of the cell membrane than the protein portions.
Hydrophilic regions of the cell membrane allow passage of small molecules such as inorganic ions.
Hydrophilic portions of the cell membrane’s protein molecules create a polar region, which act like pores, and allow the passage of molecules affected by electrical charges along the surface of the region.
Movement through these pores is affected by the surface charge, size of the region and the specific nature of the protein involved.