Polysaccharides

polysaccharides

made up of many monosaccharides

convenient storage molecules

• insoluble

• being, large, not likely to move out of cells

• fold easily into compact shapes

• easily hydrolyzed

• chemically inert

• no osmotic effect

pectin

middle lamella

hemicelluloses

cell walls of plants

peptidoglycan

cell walls of bacteria

chitin

occurs in fungal cell walls

lignin

found in wall of xylem

glycoproteins/glycolipids

found on cell membranes and allows recognition of cells

cellulose

• polymer b-glucose

• b 1,4 glycosidic - difficult to hydrolyze

• linear chains due to hydrogen bonds between OH (why they’re pronouced)

• cellulose chains in groups to form microfibrils and then macrofibrils so have high tensile strength

• allows plants to become turgid

Starch

• polymer of alpha glucose

• food store in plants

• forms from two polysaccharides amylose and amylopectin.

Amylose

• alpha- glucose

• many unbranched linear chains

• alpha 1-4, glycosidic linkages causing the chain to oil

Amylopectin

• polymer of alpha glucose

• branched molecules.

• alpha 1,4 glycosidic linkages and alpha 1,6

Test for starch

iodine

turns blue black

Glycogen

polymer of alpha- glucose

stored by animals in liver and muscle and fungi

alpha 1,4 and alpha 1,6

frequent side branches increase SA to break it down into glucose

2 structural similarities and differences between glycogen and starch

• similar; both have alpha glucose monomers, both 1-4 and 1-6

• differences; starch has amylose and amylopectin glycogen doesnt, glycogen is more branched