genetic code: The basic principle of translation

The linear sequence of bases that constitutes the protein-coding information is “read” by the cell in blocks of three nucleotide residues, or codons, each of which specifies a different amino acid.

The set of rules that specifies which nucleic acid codons correspond to which amino acids is known as the genetic code.

Complementary copies of the genes to be expressed are transcribed from DNA in the form of messenger RNA (mRNA) molecules.

A mRNA molecule is bound to a ribosome, and tRNA molecules bring amino acids to the ribosome one at a time.

Each tRNA identifies the appropriate codon on the mRNA and adds this amino acid to the growing protein chain.

The ribosome travels along the mRNA so that the genetic message can be read and translated into a protein.