Carbohydrates are a class of compounds that, along with fats, constitute a major energy source for the body. Carbohydrates, as well as fats, can be stored in the body. Sugar, cellulose and starch are examples of carbohydrates that we come into contact with every day.

Bread contains starch. Starch is a long polymer made from linked glucose molecules.

Cellulose is also a polymer of glucose. It can not be digested by Humans. It forms the structural material for plants and is present in the cell wall of all plant cells.

Potatoes are not only rich in cellulose but also in starch.