Final answer:
Animals store quick energy in the form of glycogen, a complex carbohydrate and polysaccharide of glucose, primarily in the liver and muscles for immediate glucose supply when needed.
Step-by-step explanation:
Animals store a complex carbohydrate for quick energy in the form of glycogen. Glycogen is a polysaccharide composed of glucose monomers, and it serves as an important energy reserve in animals, including humans. It is particularly stored in the liver and muscle tissues. Glycogen is the stored form of glucose that's made up of many connected glucose molecules. Glucose (sugar) is your body's main source of energy. It comes from carbohydrates (a macronutrient) in certain foods and fluids you consume. When energy is needed, glycogen can be rapidly broken down into glucose to supply the body with fuel. This ability to quickly mobilize energy helps to maintain blood glucose levels and provide sustained energy during activities such as exercise.