Termination of protein synthesis
A) requires an uncharged tRNA with an anticodon complementary to the stop codon on the mRNA.
B) occurs close to the 5' end of mRNAs.
C) occurs at a single point on the mRNA whose synthesis is regulated by the Lac repressor.
D) involves a change in the usual activity of peptidyl transferase.
E) generally gives rise directly to functional proteins.

Question

Quizplus · Accepted Answer

Termination of protein synthesis involves a change in the activity of peptidyl transferase, the enzyme responsible for forming peptide bonds between amino acids. This change is triggered by the presence of a stop codon on the mRNA, which does not code for an amino acid but signals the end of translation. The other options are incorrect: there is no such thing as an uncharged tRNA that recognizes stop codons (A), termination does not specifically occur close to the 5' end of mRNAs (B), it is not regulated by the Lac repressor (C), and the proteins often require folding and sometimes post-translational modifications to become functional (E).

Termination of Protein Synthesis