antibodies/vaccines

• What are antibodies


  Proteins with specific binding sites produced by B cells
• describe the structure of an antibody

  Has two binding sites

  4 polypeptide chains light chains and heavy chains

  has a variable region which is different in every antibody

  a constant region which is the same and binds to receptors on cells such as B cells
• how do antibodies lead to the destruction of the antigen

  They cause agglutination of bacterial cells making it easier for phagocytes to locate

  They serve as markers that stimulate phagocytes to engulf the bacterial cells
• describe how monoclonal antibodies can be used in cancer treatments

  MABs produced which bind to antigens on cancer cells

  mABs are bound to drugs/ cytotoxic chemicals or radioactive material which stimulate cells death or phagocytosis
• describe how monoclonal antibodies can be used in pregnancy testing

  as urine passes through reaction zone HCG hormone binds to the

  mobile HCG antibody in reaction zone

  passes up the stick HCG hormone binds to the immobilised HCG antibodies in the results zone

  the unbound antibodies bind to antibodies in control zone

  blue dye appears in both control

  and results zones (to show

  positive result)
• describe passive immunity and give examples


  introduction of antibodies from an outside source

  anti venom
• Describe active immunity and give examples

  stimulating the production of antibodies by own immune system - direct contact with the pathogen

  vaccination
• what is vaccination 


  The introduction of antigen to stimulate and immune response
• describe how vaccines work

  1. dead or inactive form of the pathogen injected
  2. antigens trigger immune response B-lymphocyte is activated and plasma and memory cells are produced
  3. antibodies are produced
  4. memory cells remain in the body if pathogen encountered again they divide and produce plasma cells rapidly
• name some features of a successful vaccination program

  Economically available

  few side-effects

  easily produced transported and stored

  possible to achieve heard immunity
• Give some reasons why vaccination may not eliminate disease

  • Vaccination fails to induce immunity in certain individuals
  • The pathogen may mutate frequently - antigen variability
  • Individual objections may be religious ethical or medical
• What are some ethical issues of using vaccines

  • Often involve the use of animals
  • Vaccines have side-effects that may cause long-term harm
• Describe how vaccination can lead to immunity

  1. Dead or inactive pathogen present
  2. B-lymphocyte binds to antigen
  3. B-lymphocyte present antigens on the surface
  4. T-lymphocyte bind to antigens stimulate B cells to divide and produces plasma cells
  5. Memory cells remain in blood become activated if pathogen re-encountered
• what is a monoclonal antibody?

  antibodies with the same tertiary structure, produced from cloned B cells