This profile was constructed using a random distribution of the appropriate percentages of the fatty acids in 33 representative triglyceride molecules. Red is used for saturated , green for monounsaturated , and blue for polyunsaturated fatty acids. Although the composition of the individual triglyceride molecules may vary, the relative proportion of fatty acids remains constant. The profiles for canola oil or olive oil would be mostly green and blue with very little red, whereas the profile for coconut oil would be mostly red.
The basic structure of phospolipids is very similar to that of the triglycerides except that C–3 ( sn 3)of the glycerol backbone is esterified to phosphoric acid. The building block of the phospholipids is phosphatidic acid. Substitutions that can be added to phosphatidic acid include ethanolamine (phosphatidylethanolamines, PE), choline (phosphatidylcholines, PC: also called lecithins), serine (phosphatidylserines, PS), glycerol (phosphatidylglycerols, PG), myo -inositol (phosphatidylinositols, PI: these compounds can have a variety in the numbers of inositol alcohols that are phosphorylated generating polyphosphatidylinositols), and phosphatidylglycerol (diphosphatidylglycerols, DPG; more commonly known as cardiolipins). See the Lipid Synthesis page for images of the various phospholipids.