Andy Webster, age 13, of Albuquerque, N.M., for his question:

WHAT IS A CARBOHYDRATE?

A carbohydrate is one of the three main classes of food essential to the body. The others are protein and fats.

Carbohydrates provide living things with much of the energy they need to operate muscles and nerves and to build and repair plant and body tissues. Carbohydrates are made during photosynthesis, or the food making process, in green plants.

Sugar is 100 percent carbohydrates while rice is 90 percent.

Other foods high in carbohydrates are the following: prunes, 73.3 percent; cane molasses, 69.3 percent: oatmeal, 67.5 percent; lima beans, 65.9 percent: white bread, 53.1 percent; whole wheat bread, 49.7 percent; banana, 22 percent; and corn, 19.2 percent.