2. The Ser and Thr residues are nearly always on the surface of the glycoproteins.
3. Collagen is a fiberous protein. Cellulose, although a polysaccharide, plays a structural role in plants. Althought amylopectin and starch are storage polysaccharides, they are found in plants. Only glycogen is found in animals.
4. Check the structures in Ch. 16.19 and 16.20; remember the designations of the bonding; and recall that starch can be digested wheras cellulose cannot.
5. The planar and helical structures are shown in Figs. 16.19 and 16.20.