Penicillin kills bacteria by inhibiting the biosynthesis of the cell wall. How does penicillin cause the inhibition?
A) The transpeptidase of the bacteria binds to methicillin.
B) The carbonyl carbon of the $\beta$-lactam ring of penicillin binds to transpeptidase.
C) The $\beta$-lactam ring in penicillin is hydrolyzed.
D) The glycine in transpeptidase binds to penicillin.

Question

Quizplus · Accepted Answer

Penicillin contains a beta-lactam ring that is similar to the D-Ala-D-Ala substrate of transpeptidase, an enzyme involved in the biosynthesis of bacterial cell wall. The carbonyl carbon of the beta-lactam ring reacts with a serine residue in the active site of transpeptidase, irreversibly inhibiting its activity and preventing the crosslinking of peptidoglycan chains necessary for cell wall synthesis.

Penicillin Kills Bacteria by Inhibiting the Biosynthesis of the Cell β\betaβ

Penicillin Kills Bacteria by Inhibiting the Biosynthesis of the Cell $\beta$