Carbohydrates, more commonly known as sugars, are made up of carbon, oxygen, and hydrogen atoms. the smallest unit of a carbohydrate is a monosaccharide. two monosaccharides make up a disaccharide, and many monosaccharides make up a polysaccharide. disaccharides and polysaccharides can be hydrolyzed back into the individual monosaccharide units.