Carbohydrates (sugar)

Polysaccharides

Celullose is the most common organic component of the planet. It is a polysaccharide containig hundreds or thousands of glucose units joined together. It is a natural polymer.

Cellulose

It constitutes the cell walls of plants. It also forms (along with other polysaccharides) the structure of plants. Wood has about 45% of cellulose. It is interesting to note that the glucose produced during photosynthesis can form a variety of polymers and consitute the whole structure of a plant (or tree).

 

Starch is a polysaccharide made of glucose units joined together. It is produced by plants for energy storage. It is found in various staple foods like pasta, potato, cassava, corn etc... There are two polymeric structures that form starch: amylose and pectin. Amylose is shown below:

 

Starch (amylose)

Glycogen is the polysaccharide that stores energy in animals (similar to the role of starch in plants), although the main energy storage in animals is in the form of lipids. Its structure is more branched than in the case of starch:

Glycogen