What occurs during the termination phase of translation?

During the termination phase of translation, the crucial event that takes place is that the ribosome reaches a stop codon on the mRNA. These stop codons, which are UAA, UAG, and UGA, do not code for any amino acid. Instead, they signal to the ribosome that the protein synthesis process is complete.

When the ribosome encounters a stop codon, a release factor enters the A site of the ribosome. This release factor promotes the hydrolysis of the bond between the polypeptide chain and the tRNA in the P site, leading to the release of the newly synthesized polypeptide from the ribosome. Subsequently, the ribosome disassembles, freeing the mRNA and the tRNA, thus concluding the translation process.

In contrast, other options pertain to different processes. The formation of a new polypeptide chain is part of the elongation phase, where amino acids are added to the growing chain. The exporting of mature mRNA to the nucleus refers to a post-transcriptional modification and occurs before translation, while splicing of introns from RNA is also a pre-translation process dealing with RNA maturation. Therefore, the termination phase specifically involves the ribosome recognizing the stop