HIV and AIDS

• What is the outer layer of a HIV particle called?

  Lipid envelope
• What protects the genetic information inside a HIV particle?

  Capsid
• What type of genetic material does HIV have?

  RNA
• What are the glycoproteins on the HIV envelope?

  Antigens and entry proteins
• What is the function of reverse transcriptase in HIV?

  Converts HIV RNA into viral DNA
• What type of body cells does HIV infect?

  Helper T cells
• How does HIV affect helper T cells?

  It destroys the cells and reduces the humoral response over time
• What happens when the number of T cells decreases due to HIV?

  It leads to AIDS, weakening the immune system
• What is AIDS?

  Acquired immunodeficiency syndrome
• How is AIDS caused by HIV?

  By the destruction of the immune system through T cell depletion
• How can a person be diagnosed with HIV?

  Low white blood cell count or viral DNA test
• What is the first step in HIV replication?

  Glycoproteins bind to CD4 receptors on helper T cells
• What does reverse transcriptase do during HIV replication?

  Converts HIV RNA into viral DNA
• What happens to the viral DNA in the host cell?

  The DNA is inserted into the host cell's DNA
• How are new HIV viruses assembled in host cells?

  By transcribing the viral DNA then using using the host's ribosomes to make HIV proteins
• How is HIV transmitted?

  Through blood, sexual fluids, and breast milk
• What is vertical transmission of HIV?

  Transmission from mother to child during birth or breastfeeding
• When are babies tested for HIV and why?

  At 18 months because it takes time for the virus to replicate
• What triggers the onset of AIDS in HIV-positive individuals?

  When helper T cell numbers reach a critical low level
• What are the initial symptoms of AIDS?

  Repeated opportunistic infections e.g respiratory infections
• How long does it take for an HIV-positive person to develop AIDS without treatment?

  Around 10 years
• What is the function of antiretroviral drugs?

  They slow HIV replication so reduce the viral load (number of virus particles in the blood)
• Why can't antiretroviral drugs cure HIV?

  Because they can't remove the viral DNA, only slow its replication
• What is pre-exposure prophylaxis (PrEP)?

  A prevention strategy where HIV-negative people take antiretrovirals before exposure
• How have some people been 'cured' of HIV?

  Through stem cell therapy and bone marrow transplant so their T helper cells have a CD4 mutation that prevents HIV entering cells