Polysaccharides

Polysaccharides

Consists of many monosaccharides linked together

Starch, glycogen and cellulose are polysaccharides all composed of glucose molecules but differing by their type of bonding

Starch - potato, wheat, rice

Glycogen - muscle cells, liver

Cellulose - plant cell walls, paper

Plants

Starch is a good storage for energy

--> glucose molecules can be removed from the amylose and amylopectin chains and transported away or used in the cell

The polysaccharide is also less soluble than glucose which means that water is not drawn into the cells by osmosis causing swelling of cells

Starch is a polysaccharide composed of two types of starch:

• Amylose (unbranched chains linked a 1 --> 4 glycosidic bonds between glucose molecules) which forms a curved helix

•  Amylopectin (branched chains with a 1 --> 6 glycosidic bonds) forming a straight chain

Animal and Fungi

Glycogen serves as energy storage for glucose in animals cells

Molecules of glucose can easily by hydrolysed and used

Glucose is made in muscle and liver cells of animals

Mostly insoluble in water, preventing water to enter cells by osmosis and swelling to occur

Glycogen is a branched polysaccharide of glucose units similar to amylopectin

• There are more a 1 --> 6 glycosidic bonds

• More complex die to the higher number of branches