Question

Why are most animals that can readily digest starch unable to digest cellulose? describe the structural details of storage and structural carbohydrates.

Answer 1

Answer-

According to the given question-

• Starch is a carbohydrate, made up of several units of glucose joined by α 1,4 glycosidic linkage. Starch is produced by photosynthetic green plants that serve as storage of energy. Starch has two polymers, one is a linear polymer called amylase, while the other is a branched polymer called Amylopectin. Humans as well as animals have enzyme amylases that sequentially break down starch into glucose.
• Cellulose- is a type of fibrous carbohydrate found in cell walls of plants. Cellulose is also a linear polymer made up of several units of glucose held together by β-1, 4-glycosidic bond.
• Most animals and humans cannot digest due to lack of enzymes cellulase which has the capability to hydrolyze β-glycosidic linkages present in cellulose and break into glucose monomer.
• Carbohydrates are divided into two types such as structural carbohydrates and Storage or non-structural carbohydrates.
  • Structural carbohydrates work as fiber components and found in the cell walls of plants, some other organisms such as cellulose, hemicelluloses, pectin, and fructan, and they also digested but at a slow rate and responsible for providing sustained energy for a longer period of time.
  • Storage or non-structural carbohydrates are easily digested by enzymes found in animals and at a rapid rate and provide quick energy such as sugars and starch.
• Excess amount of dietary carbohydrates which are responsible for providing glucose for requirement of energy are converted into glycogen which is also a storage form of carbohydrate, can also changed into fat for storage in fat cells.