The tails of phospholipid molecules turn inward because they are hydrophobic, meaning they repel water. Phospholipids are composed of a hydrophilic (water-loving) head and two hydrophobic (water-repelling) tails. In an aqueous environment like the cell membrane, phospholipids arrange themselves in a bilayer with their hydrophobic tails facing inward. This arrangement allows the tails to avoid contact with the surrounding water molecules and maintain stability. Additionally, the hydrophilic heads interact with the surrounding water molecules, providing stability to the lipid bilayer structure.
