Which type of polysaccharide contributes to the structure of plant cell walls?

Cellulose is the polysaccharide that significantly contributes to the structure of plant cell walls. It is a complex carbohydrate made up of long chains of glucose molecules linked together by β(1→4) glycosidic bonds. This structural arrangement creates a rigid and strong framework that provides plants with physical support and resistance to external stresses.

Cellulose is critical for maintaining the integrity of plant cells, as it helps to keep them turgid and prevents them from wilting. The strength and toughness of cellulose allow plants to grow upright and reach toward the sunlight, which is essential for their survival and photosynthesis.

Other polysaccharides mentioned do not play the same structural role. Starch, for example, serves primarily as an energy storage form for plants, while glycogen is the energy storage polysaccharide found in animals. Sucrose is a disaccharide used for energy transport within plants, not for structural purposes. Thus, cellulose is uniquely suited for the development and maintenance of plant cell walls.