Study Notes
Antibiotics are medications that prevent the growth of bacteria or kill them without harming the host's cells. They work by disrupting processes like cell wall construction and protein synthesis. Penicillin affects bacteria by blocking the production of cross-links in their cell walls, causing them to burst due to osmotic pressure. Antibiotic resistance occurs when bacteria mutate and survive despite antibiotic treatment, leading to resistant strains that can spread through vertical and horizontal transmission.
- Antibiotic — a medication that prevents the growth of bacteria or kills them. Example: Penicillin.
- Penicillin — an antibiotic that blocks the production of cross-links in bacterial cell walls. Example: Causes bacteria to burst due to osmotic pressure.
- Antibiotic Resistance — when bacteria mutate and survive despite antibiotic treatment. Example: MRSA is resistant to methicillin.
- Vertical Transmission — passing of resistance genes from parent to offspring in bacteria. Example: Binary fission in bacteria.
- Horizontal Transmission — transfer of resistance genes between bacteria through plasmids. Example: Conjugation between bacteria.
Exam Tips
Key Definitions to Remember
- Antibiotic
- Penicillin
- Antibiotic Resistance
- Vertical Transmission
- Horizontal Transmission
Common Confusions
- Antibiotics are effective against viruses.
- All bacteria are resistant to antibiotics.
Typical Exam Questions
- How does penicillin affect bacteria? Penicillin blocks the production of cross-links in bacterial cell walls, causing them to burst.
- Why are viruses unaffected by antibiotics? Viruses lack cell walls and organelles that antibiotics target.
- What are the consequences of antibiotic resistance? Increased human illness, mortality, and treatment costs.
What Examiners Usually Test
- Understanding of how antibiotics work and their limitations.
- The process and impact of antibiotic resistance.
- Differences between vertical and horizontal transmission of resistance.