Compounds have many functions that encourage a human cell and a human body to function. Compounds are pure substances made up of atoms of two or more elements chemically combined together in fixed ratios determined by mass.hemically, carbohydrates are organic molecules made up of carbon, hydrogen, and oxygen and are produced by green plants in the process of undergoing photosynthesis. A carbohydrate can be broken down into four different chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides.