the diffusion of any substance across a membrane also depends on its solubility in lipids the major constituent of the membrane. comment

as we all know that the cell membrane is composed of lipids that are arranged in a bilayer and within the membrane, with the polar head towards the inner part and non polar towards outer side. since the non polar head lies towards outer side, it ristricts the polar molecules to pass through it..

hence we can say that the diffusion of any substance across a menbrane also depends on its solubility in lipids that are the major constituent of the membrane.

hope u got this.

ChEErs!!! :)