Genetic Code: Translation Rules and Variants

Definition and purpose of the genetic code

The genetic code is the set of rules used by living cells to translate genetic information stored in DNA or RNA sequences (as nucleotide triplets called codons) into proteins. During translation, the ribosome reads mRNA three nucleotides at a time, while transfer RNA (tRNA) molecules deliver specific amino acids in the order specified by those codons. In most cases, each codon corresponds to a single amino acid, and the code can be represented in a 64-entry table (with some exceptions such as variant codes found in mitochondria). The purpose of the genetic code is to ensure that the sequence of nucleotides in a gene is converted into a specific protein sequence, thereby enabling protein biosynthesis. Because the genetic code is highly similar across organisms and is largely “canonical” (standard), it provides a universal framework for how genetic information becomes functional biological molecules. Stop codons also play a key role by signaling termination of translation when no matching tRNA is available, preventing the ribosome from producing an incorrect or overly long protein.

0/2 modes complete

Codons as mRNA triplets

0/2 modes complete