Phospholipids are a class of lipids and are a major component of all cell membranes. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule's sphingomyelin, which's derived from sphingosine instead of glycerol. They're a type of molecule. They form a lipid bilayer within a cell membrane. Amphipathic character The 'head' of a phospholipid's hydrophilic (attracted to water) whereas the hydrophobic 'tails' repel wat… (More on Phospholipids)