Tetracyclines inhibit protein synthesis by:: (A) Inhibition of initiation and misreading of mRNA, (B) Binding to 30 S subunt and inhibiting the binding of aminoacyl-RNA to A site, (C) Inhibiting peptidyl transferase activity, (D) Inhibiting translocation
Answer is B. The tetracyclines are primarily bacteriostatic; inhibit protein synthesis by binding to 305 ribosomes in susceptible organism. Subsequent to such binding, attachment of aminoacyl-t-RNA to the mRNA-ribosomc complex is interferred with. ESSENTIALS OF MEDICAL PHARMACOLOGY page no. 734