Structure. Glycerolipids are one of the eight categories of lipids and contain tens of thousands of lipid species. All of these feature a similar molecular structure: they consist of a glycerol backbone, a simple compound with three hydroxy groups. One of the hydroxy groups is ester- or ether-linked to a fatty acid or fatty alcohol. The remaining two can feature further substituents such as sugars or additional fatty acids.
Function. Glycerolipids are common to all living organisms where they are important structural and functional components of all cells. But great differences apply regarding the types of glycerolipids to be found in an organism. Glycerol esters are the most prominent type of glycerolipids. They serve as energy storage in plants, animals, and fungi, or as messengers in cellular signaling.
Glycoglycerolipids are important membrane components of plants and bacteria. They are essential to photosynthesis in the chloroplasts of plants and in photosynthetic bacteria. Glycerol ethers are essential membrane components in archaea and present in some marine animals. Little is known about further, more exotic glycerolipids.