Glycogen is classified as what type of substance?

Glycogen is classified as animal starch because it serves as a form of energy storage in animals, similar to how starch functions in plants. It is a polysaccharide made up of glucose molecules linked together and is primarily stored in the liver and muscle tissues in animals. When energy is needed, glycogen is broken down into glucose that can be utilized for metabolic processes.

While starch is the carbohydrate storage form in plants, glycogen is specifically the equivalent storage form in animals, making the identification of glycogen as animal starch appropriate. In contrast, proteins and fats are fundamentally different types of macromolecules, involved in different biological functions and not classified as starches.