Final answer:
Chitin is a structural polysaccharide found in the exoskeleton of insects and the cell walls of fungi, formed by the polymerization of N-acetyl-β-d-glucosamine, a modified sugar with nitrogen.
Step-by-step explanation:
Structural Polysaccharides in Insects and Other Organisms
Another structural polysaccharide used in insects and the cell walls of fungi is chitin. Chitin is a tough, complex carbohydrate (polysaccharide) that composes the exoskeleton of insects, arthropods, and the cell walls of fungi. Structurally similar to cellulose, chitin offers rigidity and protection.
It is formed by the polymerization of N-acetyl-β-d-glucosamine, which is a modified sugar with a nitrogen-containing group attached, making it distinct from cellulose that comprises plant cell walls.
Chitin is also characterized by its formation in a matrix with other polysaccharide polymers like hemicellulose, pectin, and agaropectin, providing additional structure to the organism's cell wall.