Macrolides exert their antibacterial effect by inhibiting which process?

Macrolides exert their antibacterial effect by inhibiting which process?

• A. Protein synthesis
• B. DNA replication
• C. Cell wall synthesis
• D. RNA transcription

Answer: (A)

Macrolides inhibit protein synthesis by binding to the bacterial 50S ribosomal subunit and blocking the translocation step of translation. This prevents the peptidyl-tRNA from moving from the A site to the P site, stopping elongation of the polypeptide chain and thereby halting protein production. Since the target is the ribosome during translation, macrolides do not directly affect DNA replication, RNA transcription, or cell wall synthesis. This is why the antibacterial effect comes from inhibition of protein synthesis, with the possible note that macrolides are often bacteriostatic (and may be bactericidal for certain organisms at higher concentrations).

Macrolides inhibit protein synthesis by binding to the bacterial 50S ribosomal subunit and blocking the translocation step of translation. This prevents the peptidyl-tRNA from moving from the A site to the P site, stopping elongation of the polypeptide chain and thereby halting protein production. Since the target is the ribosome during translation, macrolides do not directly affect DNA replication, RNA transcription, or cell wall synthesis. This is why the antibacterial effect comes from inhibition of protein synthesis, with the possible note that macrolides are often bacteriostatic (and may be bactericidal for certain organisms at higher concentrations).