This document summarizes polysaccharides and glycans. It discusses homopolysaccharides including fructosan, galactosan, and glucosans such as starch and glycogen. Starch is made of amylose and amylopectin and forms helical structures with iodine. Cellulose is composed of beta-glucose units linked by beta-1,4 bonds, forming long straight chains strengthened by hydrogen bonds. Glycosaminoglycans discussed include hyaluronic acid, chondroitin sulfate, keratin sulfate, dermatan sulfate, and heparan sulfate. Proteoglycans are composed of core proteins with covalently linked glycosaminoglycan side chains. They