Monomers
Carbohydrate monomers are called "monosaccharides." Also known by by the name "simple sugars," these molecules have the distinctive quality of tasting sweet to humans and most other mammals. The main monosaccharides are glucose, fructose, and galactose.
Polymers
In the combination of the monosaccharides listed above, carbohydrate macromolecules called "polysaccharides" are made. The simplest of these, the disaccharides, are simply a combination of two different simple sugars. The most common of these is sucrose, which is a combination of glucose and fructose. Another common disaccharide is lactose, which is a combination of glucose and galactose. Adding more monosaccharides yields more and more complex molecules. Large glucose chains can form cellulose, starch, and glycogen.