Glycogen is the energy storage in animals, starch is the energy storage in plants, and cellulose makes up the cell wall in plants (chitin makes up cell wall in fungi and exoskeleton of arthropods).
Function of polysaccharides by: Umer Parvez
The main function of starch, glycogen, and cellulose is that on hydrolysis they yield "Glucose" that is the source of the energy.
Function of cellulose, glycogen and starch by: Anonymous
Cellulose is a polysaccharide composed of crepeating units of cellobiose (Glc beta 1,4 Glc). As it has beta linkages , the glucose molecule twist at 180 degree angle w.r.t previous glucose molecule, giving cellulose a twisted ribbon structure which provides strength to the cell wall of plants to withstand atmospheric pressures.
Glycogen is the stored reservoir of energy in animals. It is highly branched and is stored in the liver of animals adn is used whenever there is a metabolic need.
Starch is the storage polysaccharides in plant. It is their reservoir of food. They store starch as starch granules.