Kathryn Zimmerman, ago 11, of Marshal; .for her question:

How do leaves make food?

This is a very popular question, perhaps because the process is so hard to believe. Green leaves make plant food from air, water and sunlight. This basic plant food is changed into wood, bark, petals, perfume, seeds or anything else the plant needs. We live on vegetables, meat and deity food. The vegetables are made from the food manufactured by the green leaves. The meat and dairy food comes from animals who fond on plant life.

So, life as we know it depends on the magic food made by green leaves. And the ingredients in the recipe are simply air, water and sunlight. The work is done by the very substance that makes the leaves green. It is a fluid teeming with tiny green bodies. The fluid is called chlorophyll. The little groan bodies are called chloroplasts. There are millions of these chloroplasts in a single leaf.

Thane are the tiny factories which work the magic recipe. They tend to cluster to the surface of leaves where sunlight is available. Here too are pores through which air passes into and out of the loaves. Water for the recipe is hauled way up from the roots of a plant. It passes up to the twigs and leaves, through a network of delicate veins.

The little chloroplasts begin work whenever the basic ingredients of air, water and sunlight are at hand, Sunlight provides the energy to make the recipe work. The chloroplasts use this energy to break down molecules of carbon dioxide from the air and particles of water from the soil.

The basic recipe calls for six molecules of carbon dioxide and six particles of water. They are broken down into six atoms of carbon, 18 atoms of oxygen and 12 atoms of hydrogen. Those atoms are then rearranged to make a different molecule. This molecule requires six atoms of carbon, six atoms of oxygen and 12 atoms of hydrogen. It is a molecule of glucose, the simply sugar which is the basis of all plant food.

If you total up the number of atoms in the basic ingredients you will find that 12 atoms of oxygen are not used in the glucose molecule. These atoms are a waste by‑product. The plant allows them to escape through the pores in the leaves.

A single chloroplast can make many molecules of glucose during a second. We know the ingredients and the results of the magic recipe but we do not know how it is done. The name for the magic process is photosynthesis ‑ meaning putting together with light. It is, after all, the sunshine recipe and only green leaves know its secret.

Without photosynthesis we would have no plant food and no meat from animals who eat plants. What's more, we would soon run out of oxygen, For the oxygen a plant gives off as waste during photosynthesis is the oxygen we breathe from the air.