Polysaccharides

• What are the characteristics of polysaccharides?

  Natural carbohydrates found as polymers , polysaccharides can be (homopolysaccharides , heteropolysaccharides , linear , branched) , do not have a defined molecular weight
• What are the characteristics of glycogen?

  branched homopolysaccharide of glucose , alpha1-4 linkage , branched at a1-6 linkers every 8-12 residues , 1 reducing end , many non reducing ends , storage polysaccharide
• What are the characteristics of starch?

  Composed of two homopolysaccharides of glucose: amylose and amylopectin. Amylose unbranched a1-4 m amylopectin branched a1-6 , main storage polysaccharide of plants
• What is the metabolism of glycogen and starch?

  glycogen and starch form granules in cells , granules contain enzymes , enzymatic processing occurs simultaneously in many non reducing ends
• What are the characteristics of cellulose?

  Unbranched homopolysaccharide of glucose , b1-4 , hydrogen bonds between adjacent monomers and chains , tough , insoluble
• What is the metabolism of cellulose?

  Fibrous structure and water insolubility make cellulose a difficult substrate, as most animals lack enzymes to act on b104 linkages
• What are the characteristics of chitin?

  made up of Nacetylglucosamine , b1-4 , hard , insoluble , flexible
• What are the characteristics of dextran?

  made up of glucose , a1-6 , branch points at a1-3
• What are the characteristics of agar , agarose?

  Heterpolysaccharide containing modified galactose units , used in lab as growth surface
• What are the characteristics of glycosaminoglycans?

  Part of proteoglycans , linear polymers of repeating disaccharide units , negatively charged , forms meshwork , extended hydrated molecule
• What are the characteristics of hyaluronic acid?

  GlcA(B1-3)GlcNAc , b1-4
• What are the characteristics of chondroitin sulfates?

  GlcA(B1-3)GalNAc4S , b1-4
• What are the characteristics of keratan sulfates?

  Gal(B1-4)GlcNAc6S , b1-3
• What are the characteristics of heparan sulfate and heparin?

  repeated idoA2S(a1-4)GlcNS3S6S , a1-4
• What are the characteristics of peptidoglycan?

  Structural functions , confers strength and rigidity to cell wall , lysozyme hydrolyses b1-4 glycosidic bond and allow osmotic entry of water
• What is a glycoprotein?

  A protein with oligosaccharide attached via its anomeric carbon
• What is a lipopolysaccharide?


  Large complex molecule composed of polysaccharides linked to lipid molecules
• What is a glycolipid?

  Lipid with covalently bound oligosaccharide
• What is a proteoglycan?

  Sulfated glucosaminoglycans attached to a large rod shaped protein
• How do cells interact with extracellular membrane?


  Receptors for extracellular proteoglycans(Integrins)