In terms of chemical composition, lipids differ from nucleic acids and proteins because they mostly just contain carbon, hydrogen, and oxygen (except for phospholipids which of course contain phosphorous). In addition to those elements, proteins contain nitrogen and sulfur, and nucleic acids contain nitrogen and phosphorous.Carbohydrates share the C, H, and O composition as lipids, but they differ in structure. Lipids are generally exist as triglycerides, which consist of a triple hydroxyl alcohol (glycerol) that has bonded to three long-chain carboxylic acids (fatty acids) in a triple condensation reaction. Carbohydrates on the other hand are made of carbon ring structures that either remain alone or polymerize into long polysaccharide chains.