What mechanism do antibiotics like penicillin use to kill bacteria?

The mechanism by which antibiotics like penicillin kill bacteria primarily involves the disruption of cell wall synthesis. Penicillin targets the enzymes responsible for cross-linking the peptidoglycan layers of the bacterial cell wall. This action is crucial because the integrity of the cell wall is essential for maintaining cell shape and preventing osmotic lysis. When penicillin inhibits these enzymes, the bacterial cell wall becomes weak and eventually ruptures under internal pressure, leading to cell death.

This mechanism is specific to bacteria and is not effective against eukaryotic cells, which do not possess a cell wall made of peptidoglycan. Thus, antibiotics like penicillin can selectively target bacterial cells, making them vital tools in treating bacterial infections. Other antibiotics may operate through different mechanisms, such as inhibiting protein synthesis or nucleic acid synthesis, but penicillin's primary and well-understood action is through the disruption of cell wall synthesis.