Chapter 26: Lipids

Phospholipids

• 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• The difference is that one of the fatty acid chains has been replaced by a phosphoric acid group.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.