What Is a Genetic Code?


Quick Answer

A genetic code is a dictionary whose "words" are formed by sequences of three nucleotides called "codons." Each codon defines or codes for a specific amino acid.

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What Is a Genetic Code?
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Full Answer

The genetic code, found in a DNA molecule, is made up of long strands that transmit instructions for general human characteristics, such as arms and legs, and shorter sequences (called "markers") that give instructions for characteristics that distinguish individuals from each other. Except in the case of identical twins, each person's genetic code is unique to that individual.

It has been determined that the genetic code is actually based upon triplets of nucleotides that provide 64 different codes using the 4 nucleotides.

The genetic code was originally translated for the bacteria E. Coli, but its universality has since been established. The genetic code is "read" from a type of RNA called messenger RNA. Each nucleotide triplet, called a codon, can be "read" and translated into an amino acid to be incorporated into a protein being synthesized.

The strand of DNA that contains the genetic code is called the anti-sense strand. It is often referred to as the template strand. The other strand (the sense strand) is not used. The sense strand has the same base sequence as mRNA except that mRNA has a U instead of a T.

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