Based on these experimental results, which conclusion about the mechanism of action of these compounds is most strongly supported? Answer: Compound A inhibits peptidyl transferase, Compound B inhibits ribosome translocation, and Compound C inhibits translation initiation.
Compound A nearly eliminates protein synthesis but doesn't affect mRNA binding, indicating inhibition of peptidyl transferase (the catalytic step of translation). Compound B causes peptidyl-tRNA accumulation, which occurs when ribosomes cannot translocate after peptide bond formation, indicating translocation inhibition. Compound C prevents ribosome-mRNA binding, suggesting interference with translation initiation. The other options incorrectly match the observed effects with the wrong mechanisms.
