Polysaccharides

Vocabulary flashcards based on lecture notes about polysaccharides.

Monosaccharide

A carbohydrate consisting of a single sugar unit.

Disaccharide

A carbohydrate consisting of two covalently joined monosaccharide units.

Polysaccharide (Glycan)

A linear or branched polymer of monosaccharide units linked by glycosidic bonds.

Carbohydrate

A sugar (monosaccharide) or one of its dimers (disaccharide) or polymers (polysaccharide).

Homopolysaccharide

A polysaccharide made up of one type of monosaccharide unit.

Heteropolysaccharide

A polysaccharide containing more than one type of sugar.

Starch

A mixture of two homopolysaccharides of D-glucose; main storage polysaccharide in plants. Heavily hydrated due to the number of exposed -OH groups, hydrolyzed by a-amylases. Contains amylose and amylopectin.

Amylose

An unbranched polymer of (a1 -> 4) linked glucose residues.

Amylopectin

A branched polymer of (a1 -> 4) linked glucose residues with (a1 -> 6) branch points every 24-30 residues.

Glycogen

A branched homopolysaccharide of glucose that functions as the main storage polysaccharide in animals. Glucose monomers form (a1 -> 4) linked chains with (a1 -> 6) linkers every 8–12 residues.

Dextrans

Bacterial and yeast polysaccharides made of poly-D-glucose forming (a1 -> 6) linked chains with (a1 -> 3) and some with (a1 -> 2) and (a1 -> 4) linkers.

Cellulose

An unbranched homopolysaccharide of glucose where D-glucose monomers form (b1 -> 4) linked chains.

Cellulases

Enzymes secreted by fungi, bacteria, and protozoa that hydrolyze (b1 -> 4) linkages in cellulose.

Chitin

A linear homopolysaccharide of N-acetylglucosamine (NAG) where N-acetylglucosamine monomers form (b1 -> 4)-linked chains.

Agar

A complex mixture of heteropolysaccharides containing modified galactose units that serves as a component of cell wall in some seaweeds.

Agarose

One component of agar with few charged groups.

Glycosaminoglycans

Linear polymers with repeating disaccharide units unique to animals and bacteria, containing sulfate groups.

Glycosaminoglycans

Extracellular heteropolysaccharides, usually with a high-density of negative charge, which provide support and aid diffusion