Final answer:
A release factor triggers the release of the now-uncharged tRNA and terminates protein synthesis by recognizing stop codons and prompting several actions, including hydrolysis, polypeptide release, and ribosomal subunit dissociation.
Step-by-step explanation:
The factor that triggers the release of the now-uncharged tRNA during the process of protein synthesis is known as a release factor. Specifically, the release factors include RF1, RF2, and RF3 in prokaryotes. This event takes place at the end of the protein synthesis process, during the termination phase. When a ribosome encounters a stop codon (UAA, UAG, or UGA) on the mRNA strand, this signals that the polypeptide chain is complete. The release factors then bind to the stop codon, leading to several key actions:
- Hydrolysis of the bond between the terminal amino acid and its tRNA.
- Release of the completed polypeptide chain.
- Dissociation of the 70S ribosome into its 30S and 50S subunits.
These actions effectively end the translation process, allowing the new protein to fold into its functional form and the ribosomal subunits to be recycled for further rounds of protein synthesis.