When bacteria are exposed to penicillin, several events occur that ultimately lead to the inhibition or destruction of the bacteria. Penicillin is an antibiotic that specifically targets bacteria by interfering with their cell wall synthesis. Here's a general overview of what happens during a penicillin attack:
1. Penicillin Binding: Penicillin molecules bind to proteins known as penicillin-binding proteins (PBPs) located on the bacterial cell wall. PBPs play a crucial role in synthesizing and maintaining the integrity of the bacterial cell wall.
2. Cell Wall Weakening: Once bound to PBPs, penicillin disrupts the formation of cross-linkages between peptidoglycan strands in the bacterial cell wall. This weakens the structural integrity of the cell wall, making it more susceptible to damage.
3. Cell Wall Lysis: As the bacterium tries to grow and divide, the compromised cell wall cannot withstand the internal pressure exerted by the cytoplasm. Consequently, the weakened cell wall undergoes lysis (rupture), leading to the release of cellular contents and the death of the bacterium.
It's important to note that penicillin primarily affects bacteria that have cell walls, such as many Gram-positive bacteria. Gram-negative bacteria have an additional outer membrane that provides some protection against penicillin. Furthermore, some bacteria have developed mechanisms, such as producing beta-lactamase enzymes, to counteract the effects of penicillin and other beta-lactam antibiotics.