Oliver C. Baker, age 14, of Huntsville, Alabama, for his question:

Why are amino acids so important?

These tiny chemical particles are the building blocks of the body’s proteins. As you know, meaty muscles are made mostly of proteins, and so are hair and fingernails. Proteins also build the hormones and assorted enzymes that trigger the body’s multitude of chemical life processes. Proteins are vital ingredients in all the living cells and tissues. And all these different proteins are built unit by unit from a small assortment of amino acids.

A diet low in amino acids results in  protein deficiency, a form of malnutrition that causes all sorts of ghastly diseases and may be fatal. An abundant and continuing supply of amino acids is essential to every aspect of growth and health. Biochemists have identified at least 22 of these key units and possibly others will be discovered. They are infinitesimally small and are made of common chemicals. You would suppose that the human body could build them from its own food ingredients. However, the tiny amino acid units are very complex. Most of the needed supply must be prefabricated by outside sources.

They are acids in which non acid hydrogen is replaced with tiny units called amino groups. An amino group is a package of three atoms, one nitrogen and two hydrogens. Molecules of various organic acids are attached to these basic groups. All amino acids contain four common elements    nitrogen and hydrogen, carbon and oxygen and some types also contain sulphur. Plants can create all their amino acids from raw materials in their environment. We eat them along with salads and vegetables, cheese and milk, eggs and fish and lean meat.

However, though prefabricated, the amino acids in the menu are not yet ready for use as protein building blocks. First the food is digested. The complicated processes of metabolism break up and re assemble it into suitable nutritional ingredients. The tiny amino acids are distributed to seep through and among the cells and living tissues. Here they wait until orders are received to use them for building proteins.

This building operation is masterminded by the DNA in cell nuclei. This miraculous biochemical blueprints and orders con6truction of required proteins. The DNA blueprint is relayed by RNA, the messenger bSochemical. When the busy cells get these orders, they select the right amino acids and assemble them in the correct patterns. Some proteins require only five amino units; others require 20 or more. A very large assortment of proteins is created by stacking just a few types of amino acids in different arrangements. At least 22 of these important amino acids are absolutely necessary to a healthy human body.

The body’s undercover building starts with the menu. At least ten or 12 of our essential amino acids must be prefabricated for us by the plant world. We acquire them by digesting plant food or by digesting plant eating animals. This explains why we also get amino acids from lean meat and dairy products.