Phospholipids are closely related structurally to the triglycerides (the
fats and oils).
The difference is that one of the fatty acid chains has been replaced by
a phosphoric acid group.
The -OH groups of this phosphoric acid unit can be involved in other ester
linkages to give phosphodiesters.
This intermediate phosphatidic acid is an important biosynthetic
precursor in the biosynthesis of triglycerides and other phosphoglycerides.
The phospholipid shown above is phosphatidyl choline (or
lecithin)
is important because its polar and non-polar components allow it to form
the micelle like bilayers that lead to the formation of cell walls, the
lipid bilayer.
