What is a codon?

A codon is defined as a sequence of three nucleotides that together specify a particular amino acid during the process of protein synthesis. This tri-nucleotide sequence is found in the messenger RNA (mRNA) and is crucial for the translation phase of gene expression. Each codon corresponds to one of the 20 standard amino acids, or it may signal the termination of protein synthesis.

The specificity of codons ensures that the correct amino acids are added in the proper sequence to form proteins, which are essential for numerous cellular functions and overall organismal health. Understanding codons is fundamental to molecular biology and genetics, as they play a key role in the translation of genetic information from DNA to functional proteins.