CBSE Class 9 Answered

Starch and glycogen are digestible forms of complex carbohydrates made of strands of glucose units linked by alpha bonds.

Starch represents the main type of digestible complex carbohydrate. Humans use an enzyme to break down the bonds linking glucose units, thereby releasing the sugar to be absorbed into the bloodstream.

Glycogen is the polysaccharide used to store energy in animals, including humans. Like starch, glycogen is made up of chains of glucose linked by alpha bonds; but glycogen chains are more highly branched than starch. It is this highly branched structure that allows the bonds to be more quickly broken down by enzymes in the body. The primary storage sites for glycogen in the human body are the liver and the muscles.