Which of the following antibiotics does NOT target bacterial ribosomes?

• A. Penicillin
• B. Streptomycin
• C. Tetracycline
• D. Erythromycin

Answer: (A)

Verified step by step guidance

1. Understand that antibiotics can target different bacterial structures or processes, such as the cell wall, ribosomes, DNA replication, or metabolic pathways.
2. Recall that bacterial ribosomes are the site of protein synthesis, and some antibiotics inhibit this process by binding to either the 30S or 50S subunits of the ribosome.
3. Identify the mechanism of action for each antibiotic listed: Streptomycin, Tetracycline, and Erythromycin all inhibit bacterial protein synthesis by targeting ribosomes.
4. Recognize that Penicillin works differently by inhibiting the synthesis of the bacterial cell wall, specifically by targeting the enzymes involved in peptidoglycan cross-linking.
5. Conclude that since Penicillin does not target bacterial ribosomes but instead targets the cell wall, it is the antibiotic that does NOT target bacterial ribosomes.