DNA is the material that lets your cells “know” which proteins are needed and how to synthesize them. You maybe aware of DNA (deoxyribonucleic acid) as the genetic material that controls inherited traits. DNA is the blueprint that contains the information to duplicate all the cells, tissues, and organs of any human being.
The complex structure of this substance was discovered in 1962 by James D. Watson, Francis H. Crick, and Maurice H. F. Wilkins, who received the Nobel Prize for their work. A review of the way DNA works helps to explain the difference in quality among proteins.
DNA is found in every reproducing cell. Although it does not actually take part in protein synthesis, DNA does establish the “code” that enables the amino acids in a particular cell to combine in the correct order and shape – from one generation of cells to the next. Although it is a very complicated process, the linking of amino acids to create a new protein in a cell occurs quickly – and it depends on a full supply of all the “coded” amino acids specified by DNA. These amino acids must be present in the specified quantities, all at the same time.
The human body needs a total of about 22 amino acids to form all its proteins. Your cells can make many of these amino acids, but 8 of them (9 for children) can only be obtained through the food you eat, and are delivered to your cells through the bloodstream.
The amino acids that cannot be created in the body, and thus must be present in the diet, are the so-called essential amino acids: leucine, isoleucine, threonine, valine, methionine, lysine, tryptophan, phenylalanine, and (for children) histidine. Although most nutrition scientists agree on the basic designations of essential and nonessential amino acids, the dividing line between the groups is not always precise.