What is the composition of the phospholipid molecules that make up the cell membrane?

The phospholipid molecules that make up the cell membrane have a polar head group and two non-polar hydrocarbon tails. The head group consists of a phosphate group and a glycerol molecule, which are polar and hydrophilic, meaning they interact well with water. The tails consist of long hydrocarbon chains that are non-polar and hydrophobic, meaning they do not interact well with water. This amphiphilic nature of phospholipids allows them to spontaneously arrange in a bilayer formation with the polar head groups facing outward and the non-polar tails facing inward, creating a barrier that separates the cell's internal environment from the external environment.