The document discusses carbohydrates and polysaccharides. It defines polysaccharides as carbohydrate molecules made of long chains of monosaccharides. Polysaccharides are found in animals, plants, and microorganisms. The document outlines two main types of polysaccharides - storage polysaccharides like starch and glycogen, and structural polysaccharides like cellulose and chitin. It provides examples of each type and describes their structures and functions.