Answer:
Phospholipid bilayer
Step-by-step explanation:
The plasma membrane is made up of a phospholipid bilayer which has polar head and hydrophobic tails that face each other keeping water out. There are proteins embedded in the membrane to selectively facilitate the movement of particles across the membrane.
Or
The plasma membrane consists of both lipids and proteins. The fundamental structure of the membrane is the phospholipid bilayer, which forms a stable barrier between two aqueous compartments.