Compounds That Compose the Human Body There are five major groups of compounds that compose the human body. They are carbohydrates, lipids, proteins, nucleotides, and water. These are all very important to humans and without them we would not be able to survive. They have many functions that encourage a human cell and a human body to function. Carbohydrates include sugars and starches, contain carbon, hydrogen, and oxygen which appears in a ratio of 1:2:1. Carbohydrates are classified according to size as monosaccharides, disaccharides, and polysaccharides. The primary function of carbohydrates is to serve as sources