Final answer:
Animals store excess glucose as glycogen mainly in the liver and muscle cells. Glycogen can be rapidly converted back into glucose when needed, and if glycogen stores are full, additional glucose is converted into fatty acids stored in adipose tissues.
Step-by-step explanation:
When food is plentiful, animals can store glucose in the form of glycogen. Glycogen is a complex carbohydrate and serves as the main storage form of glucose in the human body, particularly in the liver and muscle cells. It acts as a quickly mobilizable energy reserve, essential for maintaining the homeostasis of glucose levels in the blood. When the body requires energy and blood glucose levels are low, glycogen is broken down into glucose in a process called glycogenolysis. After glycogen stores are filled, any additional glucose can be converted into fatty acids and stored in adipose tissue cells for long-term energy supply.