HIV

• HIV structure

  Membrane envelope - outer layer

  Capsid - Protects genetic information

  RNA

  Glycoprotein - antigens

  Reverse transcriptase enzyme - turns RNA into DNA
• How HIV replicates

  1. Glycoprotein molecules on virus surface bind to CD4 receptors on surface of T helper cells, allows envelope surrounding virus to fuse with T-helper membrane
  2. Capsid released into cell, releases RNA and reverse transcriptase
  3. Reverse transcriptase used to make DNA from HIV RNA template
  4. DNA inserted into cells DNA which gets replicated
  5. DNA used to make HIV RNA and proteins at ribosomes
  6. Virus particles bud off into vesicles
• How is HIV transmitted?

  Having unprotected sex with an infected person

  Mother to child

  Use of infected blood in blood transfusion
• How AIDS is contracted

  People who have HIV when their number of T helper cells are at a critical level

  The immune system cannot fight off simple/opportunistic infections which the body would usually be able to fight off