Cotton and Potatoes. A cotton fiber consists almost exclusively of cellulose, whereas a potato tuber contains mainly starch. Cotton is a tough, fibrous, and virtually insoluble in water. The starch present in a potato tuber, on the other hand, is neither tough not fibrous and can be dispersed in hot water to form a turbid solution. Yet both the cotton fiber and the potato tube consist primarily of polymers of D-glucose in (1—>4) linkage.

a) How can two polymers consisting of the same repeating subunit have such different structures?

b) What is the advantage of the respective properties in each case?