Membrane lipids are a group of compounds (structurally similar to fats and oils) which form the double-layered surface of all cells. Most abundant lipid in plasma membrane is ______.

Phospholipids are most abundant lipids in plasma membrane. They are amphipathic molecules having a hydrophilic head group and hydrophobic fatty acid tails. Two types of phospholipids occur in bilayer: glycerophospholipids, in which the hydrophobic regions are composed of two fatty acids joined to glycerol and sphingophospholipids, in which a single fatty acid is joined to sphingosine.