Carbohydrate Chemistry Part 2 Other Carbohydrates Dr Kevin

Carbohydrate Chemistry Part 2: Other Carbohydrates Dr. Kevin Ahern

Nomenclature Fischer Form Haworth Form

Disaccharides • Sucrose (glucose + fructose) • Lactose (glucose + galactose) • Maltose (glucose + glucose)

Disaccharides • Comprised of two sugars 6 α 1, β 2 Diglycosidic Links 6 5 Glucose 1 4 1 3 2 5 4 1 5 2 2 3 6 4 3 6 Fructose 2 5 4 Glucose 1 Fructose Sucrose 3 Sucrose α-D-glucopyranosyl-(1→ 2)-β-D-fructofuranoside

Disaccharides • Lactose and Maltose Glucose 6 Galactose 6 5 4 6 2 1 5 2 6 5 5 1 4 3 4 Glucose 1 4 2 1 2 3 3 3 β-1, 4 Glycosidic Bond Lactose β-D-galactopyranosyl-(1→ 4)-D-glucose α-1, 4 Glycosidic Bond Maltose α-D-glucopyranosyl-(1→ 4)-D-glucose

Reducing Versus Non-Reducing Sugars

Oligosaccharides • Found in glycoproteins • Play roles in cellular identity

Polysaccharides • • • Cellulose Glycogen Amylose Amylopectin Chitin

Polysaccharides • Sugar Polymers With Glycosidic Bonds β-1, 4 Glycosidic Links Glucose Cellulose

Polysaccharides • Sugar Polymers With Glycosidic Bonds α-1 -4 Glycosidic Links 4 1 Glucose Amylose - component of starch

Polysaccharides Amylose - component of starch

Polysaccharides α-1, 6 Glycοsidic Link Branches α-1, 4 Glycosidic Links Glucose 1 1 Glucose 6 6 4 1 Glucose Amylopectin - component of starch

α 1, 6 links Polysaccharides • Sugar Polymers With Glycosidic Bonds α 1, 4 links Glucose Glycogen Glucose

Modified Polysaccharides Chitin in the wing of a sap beetle

Modified Polysaccharides Pectin - gelling agent Galacturonic acid polymer α-1, 4 bonds

Polysaccharides Binding Lectins - proteins that bind carbohydrates specifically Part of innate immune system Mannose binding lectin targets microbes Phytohemagglutinins in plants Used by bacteria/viruses for cellular attachment Tamiflu inhibits neuraminidase necessary for exit of flu virus

Glycolipids • Glycoglycerolipids and Glycosphingolipids

Glycolipids • Glycoglycerolipids Sugar Diacylglycerol

Glycolipids • Glycosphingolipids Single Sugar Sphingolipid Backbone Cerebrosides

Glycolipids • Glycosphingolipids Complex Carbohydrate Sphingolipid Backbone Gangliosides

Glycosylation Glycosaminoglycans - polyanionic polymers of modified sugars Proteoglycans - peptides/proteins linked to polyanionic polymers of modified sugars Glycoproteins - proteins linked to oligosaccharides N-linked - joined to asparagine in protein - E. R. and Golgi apparatus O-Linked - joined to serine/threonine in protein - Golgi apparatus

Glycosylation - glycoproteins

Glycosylation - Blood typing

Glycosaminoglycans • Unbranched polyanionic saccharide polymers Chondroitin Sulfate Heparin

Structural Lullaby (To the tune of "Brahms' Lullaby") Copyright © Kevin Ahern Metabolic Melody In your sleep You can keep Learning more about sugars Fischer schemes Haworth rings D & L and everything Hydroxides Can’t collide Fav’ring chair over boat form Spatial guides Coincide With the way structures form