Ciprofloxacin, erythromycin, and acyclovir are used to treat microbial infections. ciprofloxacin inhibits dna gyrase. erythromycin binds in front of the a site on the 50s subunit of a ribosome. acyclovir is a guanine analog.
a. what steps in protein synthesis are inhibited by each drug

Ciproflaxin would inhibit transcription as it bring helicase grinds to a halt as a result mRNA cannot be made. Erythromycin would inhibit translation. The EF-tu-tRNA-aa complex cannot enter a site of a ribosome so mRNA can't be translated. Acyclovir would inhibit transcription as it is being incorporated to an mRNA strand.

Not sure what you mean by this question

If the experiment was perfomed more then once and you get the same results