The plasma membrane plays a role in transporting solutes . Cell membranes are composed of phospholipid bilayer and proteins.
All lipids are amphipathic , that is, they have hydrophilic and hydrophobic regions.
Most membrane lipids contain a phosphate group, which makes them phopholipids. Because most membrane phospholipids are built on a glycerol backbone, they are called phosphoglycerides. Some of the phosphoglycerides present in the membrane are phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol. Sphingolipids are less abundant that the phopholipids. Sphingolipids are derivative of sphingosine, an amino alcohol that contains a long hydrocarbon chain.