BIO 024: Lesson 1 - Carbohydrates: Polysaccharides

Glycans

Other name for polysaccharides

Not sweet

The taste of polysaccharides

Homoglycan

Made up of only one type of monosaccharide

Heteroglycan

Made up of two or more monosaccharides

Repeating units
Length
Type of linkage
Degree of branching

Parameters to distinguish polysaccharides

Storage Polysaccharides

Used as energy sources in cells

Starch

Energy storage of plants

Glycogen

Energy storage of animals

Amylose & Amylopectin

Components of starch

Amylose

Straight chain glucose polymer

Amylose

Accounts for 15-20% of the starch

Amylose

300-500 monomer units of glucose

Amylopectin

Branched glucose polymer

Amylopectin

Accounts for 80-85% of the starch

Amylopectin

Contains 100,000 glucose units

Amylopectin

The more soluble of the two components of starch

Glycogen

3x more branched than amylopectin

Glycogen

1,000,000 glucose units

Structural Polysaccharide

Serves as a structural element in plant cell walls and animal exoskeletons

Cellulose

Structural component of plant walls

Cellulose

Most abundant naturally occurring polysaccharide

Cellulose

Non-digestible to humans

Cellulose

5000 glucose units

Chitin

2nd most abundant naturally occurring polysaccharide

Chitin

Gives rigidity to exoskeletons

Chitin

Found in cell walls of fungi

N-acetyl-D-glucosamine

The only difference between cellulose and chitin

Acidic Polysaccharide

Polysaccharide with repeating disaccharides

Hyaluronic acid

Contains alternating N-acetyl-b-D Glucosamine & D Glucuronate

Heparin

Small highly sulfated polysaccharide with only 15-90 disaccharide residues

D Glucuronate

Carboxylate ion formed when D Glucuronic acid loses its acidic hydrogen atom

Hyaluronic acid

Serves as the lubricant for joints

Hyaluronic acid

Associated with the jelly-like consistency of the vitreous humor of the eye

Heparin

Comes from intestinal or lung tissue of slaughtered livestock

Heparin

Blood anticoagulant

Glycosaminoglycans

Negatively charged polysaccharides

Glycosaminoglycans

Contains repeating disaccharides with one amino sugar as one of the monomers

Proteoglycans

When glycosaminoglycans attach to a protein molecule

Heparan Sulfate

Sulfated polysaccharide found as a component of cell-surface proteoglycans

Heparan Sulfate

Composed of repeating units of N-acetylglucosamine and uronic acids

Chondroitin Sulfate

Composed of repeating units of Glucuronic acid and Galactose N-acetyl-4-sulfonate

Chondroitin Sulfate

Structural polysaccharide of connective tissue

Dermatan Sulfate

Composed of repeating units of Glucuronic acid and N-acetylgalactosamine

Dermatan Sulfate

Structural polysaccharide of skin

Keratan Sulfate

Composed of repeating units of galactose and sulfated N-acetylgucosamine

Keratan Sulfate

Found primarily in the cornea of the eye

Agar

Prepared from agarose

Agar

Alternating copolymer of galactose and 3,6 - anhydrous - galactose

Inulin

Polysaccharide of fructose

Dextrin

Intermediates in the hydrolysis of starch