piece o£ cheesecloth and squeeze it in a cup of water,
In the cheesecloth bag you will find a tough, grayish
substance. In the bottom of the cup, after a few minutes,
you will find a white powder.
You have seen the white powder before if you have
made cornstarch pudding or have starched clothes. The
white powder is starch. Ask your mother for a tablespoon-
ful of cornstarch. Pick up a pinch of it in your fingers.
How does it feel? Mix a little of it with cold water. Put
it on the stove to boil. What happens? Write in your
health notebook the facts you found out about starch.
Starch is a carbohydrate. Can you guess from the name
carbohydrate two of the elements of which starch is
made? Carbon and hydrogen. That is correct. But carfep-
hydrates are made of three elements—carbon,..hydrogen,
juad oxygen. C stands for carbon, H for hydrogen, and
O for oxygen. There are usually two parts of hydrogen
and one part of oxygen, as in water. Carbohydrates, such
as starch, are formed in the green parts of plants from the
carbon dioxide of the air under the influence of the sun.
Some of the foods richest in carbohydrates are cereals,
bread, macaroni, potatoes, bananas, dried beans, sugar,
and sirups. Some of the carbohydrates, such as potatoes,
cereals, and beans, are the cheapest sources of calories.
Because carbohydrates are cheap and plentiful in most
places, they often form the bulk of the people's diet.
Carbohydrates are high in calories. That is why they
are often called fuel foods.
PROTEINS
Do you remember the other substance you found in
flour—the tough, grayish substance in the cheesecloth