Illustrated Glossary of Organic Chemistry

Peptidoglycan: A biopolymer consisting of amino acids and carbohydrates, forming the cell wall of most bacteria. Damaged or incomplete peptidoglycan can result in bacterial death. Penicillin antibiotics kill bacteria by interfering with peptidoglycan biosynthesis.

This transamidation reaction is a key step in peptidoglycan biosynthesis. Penicillin inhibits transpeptidase, the enzyme that catalyzes this process, resulting in a weakened or incomplete cell wall and bacterial death.