Amoxicillin belongs to which antibiotic class?

• A. Cephalosporins
• B. Penicillins
• C. Macrolides
• D. Tetracyclines

Answer: (B)

Amoxicillin is part of the penicillin family, a type of beta-lactam antibiotic. It works by inhibiting bacterial cell wall synthesis through the penicillin-binding proteins, which prevents cross-linking of the peptidoglycan layer and leads to bacterial death. It belongs to penicillins rather than cephalosporins, macrolides, or tetracyclines, which have different structures and mechanisms: cephalosporins are another beta-lactam class with a similar mechanism but a separate family, macrolides inhibit protein synthesis at the 50S ribosome, and tetracyclines inhibit the 30S ribosome. Amoxicillin is specifically an aminopenicillin with good oral bioavailability, distinguishing it within the penicillin group.