This is a collection of web source of The Genetic Code.
Definition of Genetic Code: The genetic code is a reference system that allows a cell to make proteins by reading its nucleotides , into amino acids . For example, the DNA word, AAT, maps to the amino acid “leucine.” The genetic code is universal: the same triplet of nucleotides corresponds to the same amino acid in all living beings.
There are several groups of nucleotide triplets that can “code” for the same amino acid. This redundancy in the genetic code is extremely valuable: If, spontaneously or resulting from external causes (radiation, chemical agents, etc.), an AAT sequence becomes AAC (transcribed as UUA and UUG in m RNA ), the organism will experience no consequences because these two codons correspond to the same amino acid (leucine). But, other DNA mutations can lead to errors in the protein that cause it to function abnormally and give rise to consequences as serious as cancer . Genetic engineering takes advantage of the universality of the genetic code to produce human proteins within bacteria ; you do this by injecting the bacteria with the DNA sequence that codes for the protein.
Discovery of the genetic code — Marshall Nirenberg
http://www.calstatela.edu/faculty/nthomas/nirenber.htm
FRONTIERS IN BIOSCIENCE: GENETIC CODE
http://www.bioscience.org/atlases/genecode/genecode.htm