2.4.1 HIV

• What is the process by which bacteria divide?

  Binary fission
• What happens to circular DNA during binary fission?

  It replicates once
• How many times do plasmids replicate during binary fission?

  Many times
• What occurs to the cytoplasm during binary fission?

  The cytoplasm expands
• Where does the DNA move during binary fission?

  To opposite poles of the cell
• What happens to the cell membrane during binary fission?

  It grows between the two DNA molecules
• What is the result of the cytoplasm splitting in half?

  Two identical daughter cells form
• What does each daughter cell contain after binary fission?

  A single copy of circular DNA
• What is the variable component in daughter cells after binary fission?

  A variable number of plasmids
• What does HIV stand for?

  Human Immunodeficiency Virus
• What does AIDS stand for?

  Acquired Immunodeficiency Syndrome
• What is the host cell for HIV?

  T-helper cell
• What are the components of the HIV virus?

  Genetic material (RNA), reverse transcriptase, protein attachments, capsid, lipid envelope, matrix
• What is the function of the lipid envelope in HIV?

  • Fuse with host cell membrane
  • Gains entry for the virus
• What is the function of the capsid in HIV?

  • Protect genetic material (RNA)
• What is the function of protein attachments in HIV?

  • Bind to receptors on host cell
• What is the role of reverse transcriptase in HIV?

  • Make viral DNA from viral RNA
• How does HIV enter a T-helper cell?

  By binding to receptors and fusing membranes
• What does reverse transcriptase do in HIV replication?

  Produces viral DNA from viral RNA
• What is the role of integrase in HIV replication?

  Integrates viral DNA into host DNA
• What happens to viral mRNA after it is created?

  It leaves the nucleus and binds to ribosomes
• What do T-helper cells do after being infected by HIV?

  They can no longer function
• What happens to new virus particles after assembly?

  They bud out of the T-helper cell
• What is the consequence of T-helper cells being infected by HIV?

  More T-helper cells become infected
• What are the symptoms of HIV?

  Flu-like symptoms
• When does a person have AIDS?

  When T-helper cell count is below 200 cells/mm²
• What does a low T-helper cell count indicate?

  More susceptibility to infections
• How is HIV diagnosed?

  By performing an ELISA test on blood samples
• How is AIDS diagnosed?

  By counting T-helper cells in blood samples
• What are the functions of T-helper cells, B plasma cells, and T killer cells?

  • T helper cell: Activates other cells to divide
  • B plasma cell: Makes antibodies for pathogens
  • T killer cell: Creates holes in infected cell membranes
• What are opportunistic infections associated with AIDS?

  Pneumonia, intestinal infections, rare cancers
• Why can antibiotics treat bacterial infections?

  They inhibit enzymes that build cell walls
• Why are antibiotics ineffective against viral diseases?

  Viruses lack a murein cell wall
• What prevents antibiotics from reaching viruses?

  Viruses are inside host cells
• Why can't antibiotics disrupt viral metabolism?

  Viruses do not have metabolism