This exercise is designed to introduce students to techniques for lipid extraction, detection and analysis.
Lipids are important constituents of all living organisms.
They are essential components of biological membranes because they form the hydrophobic barriers which separate cells from their environment, and subdivide the interiors of cells into various compartments. Glycerolipids have fatty acids attached to the first two carbons of a glycerol molecule and a polar headgroup attached to the third position. They form bilayers because the polar headgroups are hydrophilic, while the fatty acid moieties are hydrophobic. The polar headgroups remain exposed to the aqueous phase because they form hydrogen bonds with water, whereas the fatty acids cannot and are therefore excluded from water. Consequently, the fatty acids associate together in the interior of the membrane.