HIV & ELISA test

• Label the retrovirus

  1. Attachment protein
  2. Lipid envolope
  3. Matrix
  4. Capsid
  5. Reverse transcriptase
  6. RNA

  
• Describe how HIV is replicated

  1. Attachment proteins binds to receptors on helper T cell
  2. RNA enters cell
  3. Reverse transcriptase converts RNA to DNA
  4. Viral DNA integrated into host DNA
  5. Viral mRNA and Viral proteins produced
  6. HIV assembled and leaves cell
• Describe: the ELISA test


  • Antibodies complementary to the antigen are bound to the bottom of a reaction vessel
  • When the patient sample is added, target antigens present bind to the antibody
  • Sample is washed
  • A second complementary antibody with an enzyme attached is added
  • Sample is washed
  • A substrate is added which reacts with the enzyme
  • If the target antigen is present, a colour change takes place
• Explain how the viruses became able to infect others


  • Mutation in the viral DNA
  • Tertiary structure of the viral attachment protein is altered
• Explain how HIV affects the production of antibodies


  • Less antibodies are produced
  • Because HIV destroys helper T cells
  • So few B cells differentiate to form plasma cells