What is the hydrophobic layer?

The hydrophobic layer refers to a region in biological membranes, typically formed by the lipid bilayer, where nonpolar, hydrophobic (water-repelling) tails of lipids face inward, shielding themselves from water. This structure is crucial for maintaining the integrity and functionality of the membrane, allowing it to serve as a barrier that separates the internal environment of the cell from the external surroundings. The hydrophobic layer also plays a key role in the selective permeability of membranes, enabling the regulation of substances entering and exiting the cell.