Antibiotics: Targeting Bacteria, Not Viruses
Definition
Antibiotics
Antibiotics are chemical substances that kill or inhibit the growth of bacteria by targeting bacterial structures and processes that do not exist in human (eukaryotic) cells.
- Antibiotics are chemicals that kill or inhibit the growth of bacteria by targeting processes that are unique to prokaryotic cells.
- These processes include cell wall synthesis, protein synthesis, DNA replication, and metabolic pathways that do not exist in human (eukaryotic) cells.
- However, antibiotics do not work against viruses because viruses have a completely different structure and method of reproduction compared to bacteria.
How Antibiotics Work
- Bacteria are prokaryotic cells, which means they have unique structures and biochemical pathways that are different from human cells.
- Antibiotics work by targeting these bacterial structures and processes without harming human cells.
Penicillin disrupts bacterial cell wall synthesis, causing the bacteria to burst and die.
Key Targets of Antibiotics
- Cell Wall Synthesis
- Many bacteria have a rigid cell wall made of peptidoglycan.
- Antibiotics like penicillin block the enzymes that build this wall, causing the bacteria to lyse.
- Protein Synthesis
- Bacterial ribosomes (70S) differ from eukaryotic ribosomes (80S).
- Antibiotics like tetracycline and streptomycin bind to bacterial ribosomes, preventing protein production.
- DNA Replication and Transcription
- Antibiotics such as ciprofloxacin inhibit bacterial enzymes like DNA gyrase, which are essential for DNA replication.
