HIV and viruses

• What virus causes acquired immunodeficiency syndrome (AIDS)?

  Human immunodeficiency virus (HIV)
• What type of virus is HIV?

  RNA virus
• How many RNA strands does HIV contain?

  Two RNA strands
• What is found within the protein capsid of HIV?

  Enzymes including reverse transcriptase
• What is the function of reverse transcriptase in HIV?

  Converts viral RNA into DNA
• What surrounds the HIV virus?

  Lipid envelope
• What proteins are found on the HIV lipid envelope?

  Attachment proteins
• What do attachment proteins on HIV do?

  Allow HIV to attach to host cells
• What is the main target cell for HIV?

  Helper T cells
• What molecule does the HIV attachment protein bind to?

  CD4 on helper T cells
• What happens after HIV attaches to CD4?

  The HIV lipid envelope fuses with the cell membrane
• What does reverse transcriptase do after HIV enters the cell?

  Converts viral RNA into double-stranded DNA
• Where does the viral DNA move after being created?

  Into the cell nucleus
• What can happen to the viral DNA after it integrates with host DNA?

  It can remain dormant for several years
• What happens when the HIV DNA becomes active?

  It produces RNA, including mRNA and viral genome
• What is translated by ribosomes in the cytoplasm?

  Messenger RNA into viral proteins
• What happens to the virus particles after assembly?

  They bud from the helper T cell
• What forms the lipid envelope around each virus?

  Cell membrane as they leave the helper T cell
• What is a key characteristic of HIV as a retrovirus?

  It converts RNA into DNA
• What happens to helper T cells as HIV replicates?

  They die, leading to immune system failure
• What is the result of a decreased number of helper T cells?

  Less effective immune response
• What is the condition called when a patient has a severely weakened immune system due to HIV?

  Acquired immunodeficiency syndrome (AIDS)
• What are opportunistic infections?

  Infections that occur due to weakened immunity
• What is a higher risk for patients with AIDS?

  Developing cancer
• Why can't antibiotics treat viral infections?

  Viruses lack cellular structures and metabolism
• How do antibiotics work against bacteria?

  By targeting bacterial cell structures
• What does penicillin do to bacterial cells?

  Prevents cross-linking of peptidoglycan
• What do antiviral drugs do for viral diseases?

  Inhibit key enzymes in replication cycle
• What are the steps of HIV replication?

  1. HIV attaches to CD4 on helper T cells.
  2. Lipid envelope fuses with cell membrane.
  3. Capsid enters the cell.
  4. Reverse transcriptase converts RNA to DNA.
  5. Viral DNA integrates with host DNA.
  6. Viral RNA is produced and translated into proteins.
  7. Virus particles assemble and bud from the cell.
• What are the symptoms and risks associated with AIDS?

  • Weakened immune system
  • Increased vulnerability to opportunistic infections
  • Higher risk of developing cancer
  • Cause of death in AIDS patients
• How do antibiotics differ from antiviral drugs?

  • Antibiotics target bacterial structures and metabolism.
  • Antiviral drugs inhibit viral replication enzymes.
  • Antibiotics cannot treat viral infections.