when fat soluble substances move through the bilipid layer of the plasma membrane, is it through?

Question

when fat soluble substances move through the bilipid layer of the plasma membrane, is it through bulk transport?

Answer 1

No, they can move across because of their polarity. The phospholipid membrane has a hyrophobic inner layer, where the lipds are. This is what keeps the contents of cells from intermingling. Hydrophobic molecules (like lipids and their soluables) can just slide through. Transport is for HYDROPHILIC molecules (water soluable) because they can't get through the lipid layer.

Answer 2

Osmosis (only for water molecules that go by ability of semi permeable membrane ) it is a procedure which the water molecules can go by ability of the plasma membrane ( semi permeable membrane ) from region with severe concentration of solute to region with low concentration of solute. Water molecules are sufficiently small to flow by ability of the phospholipid bilayer.