Proteoglycans hyaluronic acid content

The proteoglycans contain heteropolysaccharides known as glycosaminoglycans, an unwieldy term that emphasizes their content of hexosamines and uronic acids. Formerly glycosaminoglycans were known as mucopolysaccharides. The best known members of this group are the chondroitin sulphates and hyaluronic acid. Though they are characterized by the structure of their polysaccharide chains, these are almost invariably associated with protein, hence the term proteoglycan. 

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