Antibiotics work by targeting specific characteristics of bacterial cells to kill them or inhibit their growth, without harming human cells. this is how they can achieve their function:
- Inhibition of Cell Wall Synthesis: Some antibiotics, like penicillin, prevent bacteria from forming their cell walls, which are essential for their survival. Without a proper cell wall, bacteria cannot maintain their shape and integrity, leading to cell lysis (bursting).
- Disruption of Protein Synthesis: Antibiotics such as tetracyclines and aminoglycosides bind to bacterial ribosomes, which are different from human ribosomes. This prevents bacteria from producing essential proteins needed for their growth and reproduction.
- Interference with DNA Replication: Quinolones and fluoroquinolones disrupt bacterial DNA replication and repair mechanisms by targeting enzymes like DNA gyrase and topoisomerase, important for bacterial cell division.
- Inhibition of Metabolic Pathways: Sulfonamides inhibit the production of folic acid, a vitamin necessary for DNA and RNA synthesis in bacteria. Humans do not synthesize folic acid and must obtain it through diet, so these antibiotics selectively target bacterial metabolism.
By attacking these critical processes, antibiotics effectively eliminate bacterial infections. However, they are ineffective against viruses. Overuse can lead to antibiotic resistance, where bacteria evolve (parallel evolution) to withstand these drugs.