What is the function of a stop codon during translation?

The function of a stop codon during translation is to terminate protein synthesis. In the process of translating mRNA into a protein, codons—each made up of three nucleotides—code for specific amino acids. When a ribosome encounters a stop codon, which can be one of three specific sequences (UAA, UAG, or UGA), it signals the end of the protein-coding sequence.

Upon recognition of this codon, release factors bind to the ribosome, prompting it to release the newly synthesized polypeptide chain. This processes the termination of translation and ensures that the protein is properly formed and released. The presence of stop codons is essential for maintaining the integrity of gene expression, as they define the precise endpoints of translation, preventing the addition of extraneous amino acids to a protein and ensuring that proteins are synthesized in their correct lengths and sequences.