Question

how to identity which is a homopolysaccharide?

Answer 1

Homopolysaccharides (homoglycans) consist of a single type of monomer. Cellulose and starch are the best-known examples. However, they have very different properties. Cellulose (See CEREALS | Contribution to the Diet) consists of β-(1 → 4)-linked glucose units arranged in a ribbon-type conformation in a zigzag pattern. Parallel chains fit closely to each other and associate with multiple hydrogen bonds to give rise to long fibers, which are totally insoluble in water and relatively inert. Although subject to some swelling in water, cellulose is completely unaffected by boiling in water. Natural cellulose (cellulose I) has considerable crystallinity (60–80%), as revealed by X-ray diffraction. Starch consists of two components, viz. amylose (essentially linear) and amylopectin (branched).