Question

Which antibiotic inhibits peptide bond formation?
A) Streptomycin
B) Tetracyclin
C) Chloramphenicol
D) Neomycin

Answer 1

Hint: Antibiotic is a medicine(such as penicillin or its derivatives) that inhibits the growth of or destroys microorganisms. A peptide bond is formed between two amino acids. During translation, one amino acid is joined to another amino acid by a peptide bond and this is an important step for translation. And to inhibit translation we can use an antibiotic.

Complete step-by-step answer:

Protein synthesis is a target of a wide variety of naturally occurring antibiotics and toxins. Chloramphenicol binds to 50S ribosomal subunit and blocks peptide bond formation through inhibition of peptidyl transferase, but does not affect the cytosolic protein synthesis in eukaryotes.
Chloramphenicol prevents peptide bond formation by overlapping with the binding site of the A - site (t - RNA) and 23S rRNA on the bacterial ribosome. So, it is used to treat meningitis, plague, cholera, and typhoid. Chloramphenicol blocks the peptidyl transfer step of elongation on the 50S ribosomal unit in both bacteria and mitochondria.
Streptomycin: Streptomycin, a basic trisaccharide, binds with the 30S subunit of bacterial chromosomes and causes the misreading of mRNA at relatively low concentrations.
Tetracycline: Tetracycline binds to the 30S ribosomal subunit and interferes with aminoacyl -tRNA binding.
Neomycin: Neomycin prevents prokaryotic ribosome assembly. It is an antibiotic, used to prevent or treat skin infections, caused by bacteria. It is not effective against viral or fungal infections.

Therefore, the correct answer is Option C.

Note: Macrolides bind to the 50S ribosomal subunits, inhibiting peptidyl transfer, Quinupristin/ dalfopristin, inhibiting peptidyl transfer. Quinupristin binds to a nearby site on the 50S ribosomal subunit and prevents elongation of the polypeptide, as well as causing incomplete chains to be released. Geneticin inhibits the elongation step in both prokaryotic and eukaryotic ribosomes.