Saturday 30 January 2016

Why the DNA genome is "coded information"

(Tuesday, January 18, 2011, 12:47 PM)


 
Diagram of the "typical" eukaryotic protein-coding gene. Promoters and enhancers determine what portions of the DNA will be transcribed into the precursor mRNA (pre-mRNA). The pre-mRNA is then spliced into messenger RNA (mRNA) which is later translated into protein. (Wikipedia > Gene).

Why is it fully legitimate to say that the DNA genome is, literally "coded information"?

1. The sequences of bases in the DNA genome are Information, even in the "most restricted technical sense" ...

Information, in its most restricted technical sense, is an ordered sequence of symbols. -- Wikipedia > Information

... because the DNA is essentially constituted by a sequence (the two specular strands of the double helix) of symbols (the bases T, C, A, G - in RNA U replaces T) which are positioned along the sequence without any particular physical/chemical constraint.
=> In an entirely analogous manner, in IT, information is constituted by the "bases" of the binary code (0, 1).

2. The bases (T/U, C, A, G) are true and proper symbols because a triplet (codon) of them codes one of 20 aminoacids, plus the "STOP" tern (redundant: UAA, UAG, UGA). The "standard genetic code" is univocal (NOT bi-univocal, due to the redundancy of the genetic code itself), with reference to the "START" tern (which also codes for the amino acid Methionine).
=>In an entirely analogous manner, in IT, the "bases" of the binary code (0, 1) can code the 26 letters of the English Alphabet (and other special characters) according to the ASCIIcharacter-encoding scheme (or other encoding scheme).

3. The sequences of bases (T/U, C, A, G) grouped in triplets (codons) are grouped in "words" and "sentences" of variable length, complexity, "subroutine" structure, switches, etc. (the genes) which have a "functional meaning", because they map the DNA sequence into proteins (or or for an RNA chain that has a function in the organism), besides other structures and "housekeeping" functions.
=>In an entirely analogous manner, in IT,  the "bases" of the binary code (0, 1) can code the 26 letters of the  English Alphabet (and other special characters) according to the ASCII character-encoding scheme (or other encoding scheme) so as to form programs (relative to different "programming languages") that perform meaningful functions.



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