Which polysaccharide is primarily used for energy storage in plants?

Starch is the primary polysaccharide used for energy storage in plants. It consists of long chains of glucose units and serves as a crucial energy reserve that plants can break down when they require glucose for metabolic processes. When plants synthesize glucose through photosynthesis, they can store this energy in the form of starch. During periods of low energy availability, starch can be hydrolyzed back into glucose, providing a reliable energy source for growth, development, and maintenance.

In contrast, glycogen is mainly found in animals and serves a similar energy storage function but is not utilized by plants. Chitin is a structural polysaccharide found in the cell walls of fungi and the exoskeletons of arthropods, rather than an energy storage compound. Cellulose, while another important polysaccharide for plants, mainly serves as a structural component in cell walls to provide rigidity and support rather than energy storage. Thus, starch stands out as the specific polysaccharide that fulfills the role of energy storage in plants.