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How do three-nucleotide codons determine amino acids in proteins?

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A herd of African elephants stands at the edge of the Chobe River in Botswana, drinking water with a backdrop of dry hills and scattered green trees. — life A herd of African elephants (*Loxodonta africana*) drinking from the Chobe River, Botswana.

In biology, the genetic code functions through sequences of three adjacent nucleotides, known as codons, which dictate the assembly of proteins.

During the process of translation, the sequence of messenger RNA (mRNA) is read by ribosomes in these three-nucleotide units. Each codon corresponds to a specific amino acid or serves as a signal to terminate protein synthesis.123

The actual translation of these "words" into a protein chain is mediated by transfer RNA (tRNA) molecules. Each tRNA carries a specific amino acid to the ribosome, where it aligns with the corresponding codon on the mRNA. As the ribosome moves along the mRNA, it links these amino acids together in the order specified by the codon sequence, forming a polypeptide chain.42

Of the 64 possible codon combinations, 61 specify the 20 standard amino acids, while three act as stop signals to end the process. Because most amino acids are represented by more than one codon, the genetic code is described as degenerate.13