DS/ Reducing vs non-reducing

α (D) glucopyranosyl 1 2 fructofuranoside

β (D) galactopyranosyl 1 4 glucopyranose

Sucrose Lactose

Amylose amylopectin glycogen

cellulose

DS that are formed by the linkage of sugars derivatives

Definition and properties:Definition and properties:

*They are composed of *They are composed of many sugar residues. many sugar residues.

*All are nonreducing.*All are nonreducing.

PolysaccharidesPolysaccharides

PS/Different classification.

1- Branched vs linear 1- Branched vs linear polysaccharides.polysaccharides.

ExampleExample: amylose, inulin, and : amylose, inulin, and amylopectin, glycogenamylopectin, glycogen

2- Sturctural vs storage 2- Sturctural vs storage polysaccharides.polysaccharides.

ExampleExample: Cellulose, pectin and : Cellulose, pectin and glycogen, inulin. glycogen, inulin.

3- Homo vs hetero polysaccharides.3- Homo vs hetero polysaccharides.

Example:Example: Amylon, cellulose and Amylon, cellulose and glycosaminoglycanes glycosaminoglycanes. .

PS/ linear vs BranchedPS/ linear vs Branched Amylose Amylopectin / Glycogen

BranchedBranchedlinearlinear

Structural vs storage

Other Structural Other Structural PolysaccharidesPolysaccharides

Alginates - Ca-binding polymers in Alginates - Ca-binding polymers in algae algae

Agarose and agaropectin - and agaropectin - galactose polymers

Glycosaminoglycans - repeating Glycosaminoglycans - repeating disaccharides with amino sugars and disaccharides with amino sugars and negative chargesnegative charges

Dextrans

If you change the main linkages between If you change the main linkages between glucose from glucose from alpha(1,4)alpha(1,4) to to alpha(1,6)alpha(1,6),, you you get a new family of polysaccharides - get a new family of polysaccharides - dextrans dextrans

Branches can be (1,2), (1,3), or (1,4) Branches can be (1,2), (1,3), or (1,4) Dextrans formed by bacteria are

components of dental plaque Cross-linked Cross-linked dextrans are used as are used as

""Sephadex" gels in column " gels in column chromatography chromatography

These gels are up to 98% water! These gels are up to 98% water!

PS/Homo vs PS/Homo vs HeteropolysaccharideHeteropolysaccharide

Amylose, inulin, and Amylose, inulin, and amylopectin, glycogen, Cellulose amylopectin, glycogen, Cellulose

Chitin - exoskeletons of Chitin - exoskeletons of crustaceans, insects and crustaceans, insects and spiders, and cell walls of fungi spiders, and cell walls of fungi

Similar to cellulose, but Similar to cellulose, but C-2s are N-acetyl

Cellulose strands are parallel, Cellulose strands are parallel, chitins can be parallel or chitins can be parallel or antiparallel antiparallel

Hetero PS Hetero PS (Glycosaminoglucans)(Glycosaminoglucans)

(GAG+ peptide)

Glycoproteins vs Glycoproteins vs ProteoglycansProteoglycans

Two main classes of ECM molecules:

a) Glycosaminoglycansmostly proteoglycans

polysaccharide chains - glycosaminoglycans, GAGs, covalently bound to proteins

highly hydrated, porous, gels

b) fibrous proteins (embedded in the above gel)

structural (collagen, elastin)

strengthen the ECM

adhesive (fibronectin, laminin)

attach cells to the appropriate part of ECM

Polysaccharides/ PeptidoglycanesPolysaccharides/ Peptidoglycanes

Gram positive bacteria

Gram Negative bacteria

GlycoproteinsGlycoproteins

Glycolipids (Crebroside, Ganglioside)

Glycolipids Vs Glycolipids Vs LipopolysaccharidesLipopolysaccharides

Relative swetness & Relative swetness & Artificial sweetnersArtificial sweetners

Relative sweetness of sugar

Sucrose: 100Sucrose: 100 Glc: 70Glc: 70 Fru:170Fru:170 Mal: 30Mal: 30 Lac: 16Lac: 16

Relative sweetness of Artificial sweetners• Cyclamate: 3, Cyclamate: 3, 000000• Aspartam: 20, Aspartam: 20, 000 000 • Saccarin: 40, Saccarin: 40, 000000• Monilin: 400, Monilin: 400, 000000

Different ways for qualitative and Different ways for qualitative and quantitative identification of quantitative identification of

sugarssugarsCrystal formation(Osazones)Crystal formation(Osazones) Furfral and hydroxy furfural reaction Furfral and hydroxy furfural reaction

with cyclic alcohol.with cyclic alcohol. Iodine Iodine EnzymaticEnzymatic GlucokinaseGlucokinase

HexokinaseHexokinase Oxidative and reductive reactions: Oxidative and reductive reactions:

BenedictBenedict

Benedict: An assay for Benedict: An assay for sugarssugars

Cu+Cu2+