Infection and Response U3

• What are the 4 types of Pathogens ?

  • Bacteria - Produce toxins that damage cells

  • Viruses - Incredibly small, will explode which releases more viruses and damages cells

  • Fungi - Made from Hyphae which produce spores and can penetrate human and plant skin

  • Protists - Eukaryotic cells, some of them are parasites
• Examples of Viral, Fungal and Protist diseases


  • Viral - Measles, HIV and Tobacco mosaic virus (TMV)

  • Fungal - Rose black spot

  • Protist - Malaria
• Examples of bacterial diseases


  • Salmonella - caused food poisoning

  • Gonorrhoea - Causes pain when urinating and yellow / green discharge
• How do White blood cells defend against pathogens ?


  • Phagocytosis - White blood cells engulf pathogens and digest them

  • They produce antibodies that are specific to the pathogens antibodies
• How do vaccinations work ?


  • Injecting a weakened version of a virus to get the body to produce antibodies so the immune response is immediate
• Why do Bacteria become resistant to antibiotics ?


  • Over-pescribing medication

  • Mutations
• What are Monoclonal Antibodies ?


  • Antibodies produced from a lymphocyte
• How are Monoclonal Antibodies made ?


  • Inject a mouse with the chosen antigen

  • Extract the lymphocyte from the mouse

  • Fuse a lymphocyte and a tumour cell to form a hybridoma cell which is able to rapidly make antibodies
• How do Monoclonal Antibodies work in pregnancy tests ?


  • The testing area (were you pee on) contains antibodies with dye beads attached

  • The test strip (were you see the result) has antibodies with the hormone already attached

  • If someone is pregnant, the HCG binds to the antibodies on the blue beads, the urine moves up the stick carrying the hormone and dye beads which then bind to the antibodies on the test strip (making it blue)