These are the group of high molecular weight (large and heavy for molecules), linear (straight), hetero(different) polysaccharides having repeating disaccharide units that contain N-acetylhexosamine and an additional hexose or hexuronic acid. This class of substances includes chondroitin sulfates, keratan sulfates, hyaluronic acid, heparin sulfate, heparin and deratan sulfates. All of the former molecules except heparin (an anticoagulant) are incorporated in proteoglycans.