Module 4: Antibiotics and Their Use

These free OCR A Level Biology Antibiotics and Their Use revision notes have been written for specification point 4.1.1(n).

  1. Communicable Diseases
  2. Plant Defences Against Pathogens
  3. Non-Specific Defences in Animals
  4. White Blood Cells and Secondary Defences
  5. The Primary and Secondary Immune Response
  6. Immunity
  7. Antibodies
  8. Autoimmune Diseases
  9. Vaccination and Epidemics
  10. Developing New Medicines
  11. Antibiotics and Their Use
  12. Biodiversity
  13. Conserving Biodiversity
  14. Measuring Biodiversity
  15. Measuring Genetic Biodiversity
  16. Variation
  17. Causes of Variation
  18. Adaptations
  19. Natural Selection
  20. Evolution and Speciation
  21. Evidence for Natural Selection
  22. Charles Darwin and Alfred Russel Wallace
  23. Classification and Phylogenetics
Antibiotics: Importance and Use

Antibiotics are medicines that either kill bacteria or inhibit their growth. 

Penicillin, the first antibiotic, was discovered by Alexander Fleming in 1928 from the fungus Penicillium notatum.

Antibiotic Resistance

Antibiotic resistance occurs when bacteria evolve mechanisms to survive exposure to antibiotics. This poses a serious risk to public health, as it can make infections:

  • Harder to treat
  • More likely to spread
  • More likely to cause complications or death

MRSA (methicillin-resistant Staphylococcus aureus) is a major example of a resistant “superbug” that has become prevalent in hospitals, making routine surgery more dangerous.

The factors which accelerate the evolution of antibiotic resistance include:

FactorExplanation
Overuse of antibioticsIncreases selection pressure for resistance
Incomplete courses of treatmentLeaves behind resistant bacteria
Use in agricultureAntibiotics given to livestock may spread resistance genes to human pathogens
PreviousFull NotesNext

Powered by  GDPR Cookie Compliance
Privacy Overview

This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.