Genakóðinn

Genakóðinn is the Icelandic term for the genetic code, the set of rules by which the information encoded in genetic material is translated into proteins. The code assigns each codon—a sequence of three nucleotides in DNA or RNA—a specific amino acid or a termination signal. There are 64 codons: 61 encode amino acids, while three are stop signals. The code is nearly universal across organisms, reflecting common ancestry, though there are known variations in mitochondria and some single-celled organisms and in certain organelles where alternative codons or amino acids such as selenocysteine and pyrrolysine are incorporated under specific contexts.

Transcription copies DNA into messenger RNA, and translation uses ribosomes to read the mRNA in codons, with transfer RNA delivering the corresponding amino acids. The start codon AUG signals the beginning of translation and also encodes methionine; stop codons signal termination of protein synthesis. The code's redundancy—multiple codons for the same amino acid—provides robustness against point mutations, though changes can alter protein function (missense, nonsense, silent mutations).

Historically, the genetic code was deciphered in the 1960s by Marshall Nirenberg, J. Heinrich Matthaei, and others, leading to the standard codon map widely used in biology and medicine. In research and biotechnology, understanding Genakóðinn enables gene design, protein engineering, and genome interpretation. Ethical considerations and regulatory frameworks accompany its application.