Amylose starch is less readily digested than amylopectin. However, it takes up less space so is preferred for storage in plants. Amylose, amylopectin, cellulose, and glycogen are polysaccharides. Amylose, amylopectin are storage polysaccharides whereas cellulose and glycogen are structural polysaccharides.
cellulose is a common carbohydrate found in plants which allows the plant to stand upright by forming the basic structure of its cell wall through the process of photosynthesis. It is made up of oxygen, hydrogen and carbon as well as a derivation of glucose.
Glycogen is made primarily by the liver and the muscle, but can also be made by glycogenesis within the brain and stomach.
Glycogen or animal starch is found in animal liver, muscle tissue. Glycogen is found also in yeast, mushrooms, beans, corn on the variety of Zea mays saccharata.The structure resembles of Amylopectin and by hydrolysis, form, as starch, dextrin, and subsequently, maltose up to glucose .
Cellulose is found in the form of very fine fibers, in all plant products. It comprises glucose. It is not attacked by mineral acids or bases. Extracted from Herbal textile plants,it is used for centuries in the manufacture of cotton and linen clothes. It has not an active role in nutrition, but it has a role in promoting nutritional act, in digestion, to stimulate the intestinal tract along with dietary fiber.
Pancreatic amylase is similar to salivary amylase which acts on starch or glycogen. Parallel to the formation of amylase a small part of the enzyme goes in the blood , so determination of blood amylase gives clues to the function of the pancreas.
Starch is the most prevalent carbohydrate. It consists of two substances with different molecular weight. It is extracted from starch grains in the form of very fine granules microscopically distinguished by shape and size-specific to some plants. Rice starch is used for making cosmetic products.
Glycogen also occurs naturally in the neotropical tree Cecropia peltata, specifically in the Muellerian Bodies produced at the bases of the petioles. These are havested by Azteca ants which protect the trees from leaf-cutting Atta ants. See Rickson, Fred R. 1971, Science 173: 344-7. and West, David A. 2003. Fritz Mueller, naturalist in Brazil. Blacksburg: Pocahontas Press.