HIV + AIDS

• what is the general structure of all viruses?

  viral envelope - made up of lipids

  attachment proteins - HIV attaches to helper t - cells

  viral RNA

  reverse transcriptase - enzyme

  capsid - protein coat
• where do viruses replicate?

  inside host cells
• Antibiotics only work on bacteria, they are ineffective against viruses - this is because...

  viruses are cells that do not posses cellular structures targeted by the drugs e.g. no cell wall or ribosomes
• why do antibiotics work on bacteria?

  bacteria have mechanisms that allow antibiotics will directly attack + disrupt.
• explain the steps of viral replication?

  1. HIV attachment proteins bind to specific, complementary receptors on the surface of helper t cells
  2. The capsid, containing genetic material and the enzyme reverse transcriptase is released into the helper t - cell
  3. the reverse transcriptase converts viral RNA into viral DNA
  4. the viral DNA moves into the genome of the helper t - cell
  5. viral DNA is then used to make new viral proteins
  6. These new HIV viruses bud from the t helper cell and other Th cells are then infected
• state the symptoms of HIV?

  flu -like symptoms

  weight loss

  diarrhoea

  fever
• how does HIV cause AIDS?

  • decrease of helper t cells - destroyed by viruses
  • less helper T - cells means less B - cells and cytotoxic cells from being released
  • an inadequate immune response - vulnerable to infections and cancer
• how does AIDS occur?

  when the replicating viruses in the helper T - cell interferes with their normal functioning of the immune system.
• how are AIDS transmitted?

  • sexually transmitted
  • exchange of body fluids
• treatment of HIV?

  • antiviral drugs - target HIV, disrupt the life cycle of the virus
  • slows replication and destruction of helper T - cells
• why do we experience symptoms when being infected with HIV?

  Indicates helper - t cells being destroyed
• how is AIDS detected?

  when the replicating viruses in the helper T cells has been interfered with their normal functioning of the immune system.