Starch, Glycogen, and Cellulose

Amylose

-Polymer of alpha glucose molecules joined by 1,4 glycosidic bond

-Forms a helix held in place by hydrogen bonds, maintains compactness

-Unbranched polysaccharide

Amylopectin

-Ploymer of alpha glucose joined by 1,4 glycosidic bond

-Branched amylopectins contains 1,6 glycosidic

Starch

-Amylose forms a tight helix which makes it compact

-Insoluble in water, does not cause water to enter by osmosis

-Large in size so does not diffuse out of cells

-Forms alpha glucose when hydrolysed, which is easily transported and readily used in respiration

-Branched forms has many ends and can be acted on by enzymes simutaneously, meaning that glucose molecules are released very rapidly

Glycogen

-Polymer of alpha glucose joined by 1,4 glycosidic bond

-Glucose molecules at the branched points are joined by 1,6 glycosidic bonds

-More branched than amylopectin, very compacted

-Lots of free ends so enzymes can convert glycogen back to glucose very rapidly to be used in respiration.

-Insoluble in water, does not draw water into cells by osmosis

-Large in size so cannot diffuse out of a cell

Cellulose

-Formed by beta glucose

-Straight, unbranched chains that runs parallel to one another which allows hydrogen to form cross-linkages between adjacent chains to give its structural stability

-Cellulose molecules are grouped together to form microfibrils

-Strengthen cell walls and provides turgidity