Phospholipid Bilayer

Head Phospholipids are the most abundant membrane lipids and contain a polar head group containing the phosphate group. It is hydrophilic and faces out on each surface to interact with water.

Tail The phospholipid tail comprises two fatty acids, which are hydrophobic and do not dissolve in water. The hydrophobic tails are sandwiched between two layers of hydrophilic heads in a bilayer.