Which event occurs during translation termination?

• A. The polypeptide is released from the ribosome after recognition of a stop codon by release factors.
• B. The ribosome frameshifts to extend coding.
• C. The mRNA is reverse transcribed into DNA.
• D. The tRNA is recharged with amino acids.

Answer: (A)

Translation termination happens when the ribosome encounters a stop codon and release factors recognize it. These release factors bind in place of a charged tRNA at the ribosome’s A site and trigger the hydrolysis of the bond linking the polypeptide to the tRNA in the P site. That chemical reaction releases the newly synthesized polypeptide, ending protein synthesis. After release, the ribosome disassembles and the components are recycled for another round of translation.

Other scenarios don’t fit termination. Frameshifting would alter the coding sequence during elongation, not end it. Reversing mRNA into DNA is not part of translation at all. Charging a tRNA with its amino acid happens before or during elongation, not at termination, when the tRNA release and polypeptide release steps occur.