First - carhydrates are composed by Carbon, Hydrogen and Oxygen. Carbohydrates often suffer reactions of reduction, oxdation, amination, esterification, which gives every structur a specific property such as solubility. Now, fats are composed by several fatty acids and form mono, digli and triglicerids. This last ones are formed by Carbon, Hydrogen and Oxygen with a (-COOH) structure at the extremity. Protein, formed by linear aminoacids chains. Irs structure is determined by the aminoacids sequence. Now, steroids are derivated from the sterane, composed by Cabron and Hydrogen forming 4 merged rings, 3 hexagonals and 1 pentagonal.