Phospholipids have a hydrophilic head and a hydrophobic tail.When placed in water the molecules align so that the hydrophilic heads are close to water molecules and the hydrophobic tails are as far away as possible from the water molecules.If phospholipids are put into an aqueous environment they form a bilayer with the hydrophobic tails oriented away from the water or form micelles.The plasma membrane is formed from a phospholipid bilayer. The lipids can combine with carbohydrate chains to form glycolipids on the cell surface. Glycolipids are important in cell recognition.