Carbohydrates - Polysacharides

Posted by Cikgu Jes | 11:26 AM | 0 comments »

Monosacharides

Polysaccharides

Polysaccharides are polymers.

They are large complex sugars formed by the condensation of glucose monomers..

Examples of polysaccharides are starch, glycogen and cellulose.

Taste and Solubility

Polysaccharides do not taste sweet and do not crystallise.

Starch is soluble in water.

Glycogen and Cellulose are not soluble in water.

Starch

Starch is the major storage of carbohydrate in plants.

The presence of starch in food can be identified by the iodine test.

If starch is present, the iodine solution will change from brown to blue-black.

Figure below shows the structure of a starch molecule. It consist of 2 components –

The unbranched, helical chains of glucose.

The branched chains of blucose.

Glycogen

Glycogen is the main storage of carbo­hydrates in animals. It is also known as animal starch.

It is stored in liver and muscle cells of organism.

Figure below shows the structure of a glycogen molecule.

It is highly branched.

Cellulose

Cellulose is a structural polysaccharide in plant cells.

7 Cellulose is the substance of which plant cell walls are made of. Cellulose provides support for plant cells.




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