ـLong, unbranched polysaccharide chains (70-200 sugar residues ) composed of repeating disaccharide sugar units। The repeating disaccharides are linked by 1,4 linkages in βconfiguration.

Highly negatively charged due to sulfate and carboxyl groups.Which attract Na+ions and water.

One of two sugar residues in repeating disaccharide is always an amino sugar and may contain uronic acid
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N-acetylglucosamine
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N-acetylgalactosamine

ـmain groups of GAGs, distinguished by sugar residues, type of linkage between residues and number and location of sulfate groups
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Hyaluronicacid
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Chondroitin4 sulfate and chondroitin6 sulfate
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Dermatansulfate
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Heparansulfate and heparin
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Keratansulfate I, II