lipids are amphipathic moleules b.certain plant fatty acids are required (essential) in diets of animals c. Glycerol esterified with three fatty acids is called a sphingolipid d.Waxes are esters of long-chain alcohol and long-chain fatty acid e the short hand notation for fatty acid that is 20 carbons long with one double bond at carbon 5 can be written as 20:1(delta5)