Carbohydrates are used as fuels and building material, organic molecules made of sugars and their polymers that is large molecules consisting of many identical or similar subunits connected together through polymerization. Carbohydrates has three categories that is according to the number of simple sugars: (1) Mono saccharides (2) Oligo saccharides and (3) Polysaccharides. Polysaccharides is formed by enzyme-meditated condensation reactions and is stored in the muscle and liver of vertebrates. These are macromolecules that are polymers of a few hundred or thousand monosaccharides. Starch and glycogen are examples of polysaccharide that is use as energy storage while cellulose and chitin are polysaccharides that is use as structural support. Cellulose is a liner unbranched polymer of glucose most abundant organic molecule on the planet, reinforces plant cell walls and cannot be digested by most animals because they lack the enzyme that can hydrolyze the linkage in BLANK. While Chitin is a structural polysaccharide that is a polymer of an amino sugar, forms the exoskeleton of arthropods (insects, crawfish) and found in the cell walls of some fungi.