Antibodies

• Do antibodies have a quaternary structure?

  Yes. They are made of 4 polypeptide chains; two light chains and two heavy chains.
• What two regions do antibodies have?

  A constant region and a variable region.
• What property of antibodies allows agglutination to happen?

  Antibodies are flexible and have two binding sites for antigens. This means they can bind to two different antigens at once.
• What is the benefit of agglutination (clumping of antigens)?

  It makes it easier for phagocytes to locate and destroy the antigens.
• Name the parts of the antibody:

  A) Variable regions

  B) Hinge protein

  C) Disulfide bridge

  
• What are monoclonal antibodies?

  A single type of antibody produced by the same clone of B cells.
• What can monoclonal antibodies be used for?

  • Medical treatment
  • Medical diagnosis
  • Pregnancy tests
• Targeted medication: what is direct monoclonal antibody therapy?

  1. Monoclonal antibodies are complementary to antigens on cancer cells.
  2. They bind to the cancer cells, preventing chemicals which enable uncontrolled cell division from doing so.
  3. Prevents growth of cancer cells.
  4. Does not harm other cells.
• What is indirect monoclonal antibody therapy?

  1. Drugs are attached to monoclonal antibodies.
  2. The drugs are delivered to cancer cells, killing them.
  3. Reduces harmful side effects.
  4. Known as 'bullet drugs'.
• The ELISA test can be used to diagnose what?

  • Pregnancy
  • Influenza
  • Hepatitis
  • Chlamydia
  • Prostate cancer
• What does the ELISA test stand for?

  Enzyme linked immunosorbent assay.
• How does the ELISA test work?

  1. A test sample is added to a beaker.
  2. It is washed to removed any unbound test samples.
  3. An antibody complementary in shape to the antigen being tested for is added.
  4. It is washed to remove unbound antibodies.
  5. A second antibody, complementary to the first antibody, is added. It has an enzyme attached. Rinsed again.
  6. A colourless substrate for the enzyme is added. This will produce colourful products in the presence of the enzyme.
  7. The presence of this colour indicates the presence of the antigen.
  8. More intense colour= more antigens.
• What is an ethical issue of using monoclonal antibodies?

  The production of antibodies involves giving mice cancer.