Which of the following is a storage carbohydrate in animals?

Which of the following is a storage carbohydrate in animals?

• A. Glycogen
• B. Starch
• C. Cellulose
• D. Chitin

Answer: (A)

Animals store glucose in a form called glycogen, a highly branched polymer that is stored mainly in the liver and muscles. The branching creates many ends for enzymes to act on, so glucose can be added or removed quickly to meet energy needs during activity. Plants, by contrast, store energy as starch. Cellulose is a structural carbohydrate in plant cell walls, not used for energy storage, and its beta-linkages make it rigid and not digestible by most animals. Chitin is also a structural polymer, found in the exoskeletons of arthropods and in fungal cell walls, not a storage carbohydrate. So glycogen is the storage carbohydrate used by animals.

Animals store glucose in a form called glycogen, a highly branched polymer that is stored mainly in the liver and muscles. The branching creates many ends for enzymes to act on, so glucose can be added or removed quickly to meet energy needs during activity. Plants, by contrast, store energy as starch. Cellulose is a structural carbohydrate in plant cell walls, not used for energy storage, and its beta-linkages make it rigid and not digestible by most animals. Chitin is also a structural polymer, found in the exoskeletons of arthropods and in fungal cell walls, not a storage carbohydrate. So glycogen is the storage carbohydrate used by animals.