DS/ Reducing vs non-reducing

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DS/ Reducing vs non-reducing
Sucrose
Lactose
a (D) glucopyranosyl 1 2 fructofuranoside
ß (D) galactopyranosyl 1 4 glucopyranose
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cellulose
Amylose amylopectin glycogen
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DS that are formed by the linkage of sugars
derivatives
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Polysaccharide
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Polysaccharides

• Definition and properties
• They are composed of many sugar residues.
  
• All are nonreducing.

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PS/Different classification.

• 1- Branched vs linear polysaccharides.
• Example amylose, inulin, and amylopectin,
  glycogen
• 2- Sturctural vs storage polysaccharides.
• Example Cellulose, pectin and
  glycogen, inulin.
• 3- Homo vs hetero polysaccharides.
• Example Amylon, cellulose and
  glycosaminoglycanes.

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PS/ linear vs Branched
Amylose
Amylopectin / Glycogen
Branched
linear
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Structural vs storage
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Other Structural Polysaccharides

• Alginates - Ca-binding polymers in algae
• Agarose and agaropectin - galactose polymers
• Glycosaminoglycans - repeating disaccharides with
  amino sugars and negative charges

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Dextrans

• If you change the main linkages between glucose
  from alpha(1,4) to alpha(1,6), you get a new
  family of polysaccharides - dextrans
• Branches can be (1,2), (1,3), or (1,4)
• Dextrans formed by bacteria are components of
  dental plaque
• Cross-linked dextrans are used as "Sephadex" gels
  in column chromatography
• These gels are up to 98 water!

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PS/Homo vs Heteropolysaccharide

• Amylose, inulin, and amylopectin, glycogen,
  Cellulose
• Chitin - exoskeletons of crustaceans, insects and
  spiders, and cell walls of fungi
• Similar to cellulose, but C-2s are N-acetyl
• Cellulose strands are parallel, chitins can be
  parallel or antiparallel

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Hetero PS (Glycosaminoglucans)
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Glycoproteins vs Proteoglycans
(GAG peptide)
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Two main classes of ECM molecules a)
Glycosaminoglycans mostly proteoglycans
polysaccharide chains - glycosaminoglycans,
GAGs, covalently bound to proteins highly
hydrated, porous, gels b) fibrous proteins
(embedded in the above gel)
adhesive (fibronectin, laminin) attach cells to
the appropriate part of ECM
structural (collagen, elastin) strengthen the ECM
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Polysaccharides/ Peptidoglycanes
Gram Negative bacteria
Gram positive bacteria
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Glycoproteins
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Glycolipids Vs Lipopolysaccharides
Glycolipids (Crebroside, Ganglioside)

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Relative swetness Artificial sweetners

• Relative sweetness of sugar
• Sucrose 100
• Glc 70
• Fru170
• Mal 30
• Lac 16

• Relative sweetness of Artificial sweetners
• Cyclamate 3, 000
• Aspartam 20, 000
• Saccarin 40, 000
• Monilin 400, 000

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Different ways for qualitative and quantitative
identification of sugars

• Crystal formation(Osazones)
• Furfral and hydroxy furfural reaction with cyclic
  alcohol.
• Iodine
• Enzymatic
• Glucokinase
• Hexokinase
• Oxidative and reductive reactions Benedict

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Benedict An assay for sugars
Cu
Cu2