Question

Which antibiotic, produced by Streptomyces spp., has a naphthacene ring system, is broad-spectrum, inhibits protein synthesis by binding to the 30s ribosome subunit, and prevents tRNA from binding to the 'A' site?

A. Tetracycline
B. Chloramphenicol
C. Aminoglycoside
D. Macrolide

Answer 1

The antibiotic with a naphthacene ring system that inhibits protein synthesis by binding to the 30s ribosomal subunit and preventing tRNA from binding is Tetracycline (A).

Step-by-step explanation:

Tetracyclines, including this antibiotic, block the association of tRNAs with the ribosome during translation and are bacteriostatic. This class of drugs is differentiated from others such as aminoglycosides, which also bind to the 30s subunit but cause mistranslations and early termination of protein synthesis, and chloramphenicol, which affects the 50s subunit and inhibits peptide bond formation, thereby affecting the growth of the protein chain.