Phospholipid bilayer

The cell membrane is the part of the cell made up of phospholipid bilayer.

Explanation:

The cell membrane is made up of two layers of phospholipids and hence these layers are known as the phospholipid bilayer. The tail of the phospholipids is made up of fatty acids and it is hidden on the inside of the structure. The heads made up of phosphate and glycerol face outwards. This structure makes the cell membrane ideal for the transport of molecules as they have both hydrophobic and hydrophilic regions.