Final answer:
Glycogen is the storage form of glucose in animals, including humans. It is stored primarily in the liver and muscles and serves as an energy reserve. When food is plentiful, animals can store excess glucose as glycogen and mobilize it when energy is needed.
Step-by-step explanation:
Glycogen is the storage form of glucose in animals, including humans. It is a complex carbohydrate made up of glucose monomers and is stored primarily in the liver and muscles. When food is plentiful, animals can convert excess glucose into glycogen for storage. Then, when energy is needed, glycogen is broken down into glucose to be used by cells.