Which of the following is a storage carbohydrate in plants?

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

Answer: (A)

Plants store energy as starch. Starch is a glucose-based polysaccharide that is packed away in plastids like amyloplasts in seeds, roots, and tubers. Its structure, with mostly linear chains in amylose and branched chains in amylopectin, makes it compact and insoluble, which is ideal for a long-term energy reserve. When energy is needed, enzymes break starch down to glucose to fuel metabolic processes. In contrast, cellulose forms the rigid structure of plant cell walls, chitin is a structural polymer in fungi and arthropods, and glycogen serves as the short-term storage carbohydrate in animals. So, starch is the plant storage carbohydrate.