Transcript D7 Antivirals

D7 - Antivirals
D.7.1
• State how viruses differ from
bacteria.
List the differences you know of
between bacteria and viruses.
Bacteria
Viruses
List the differences you know of
between bacteria and viruses.
Bacteria
Viruses
• Microscopic
• Submicroscopic
• Has single, circular strand of • Has either a section of DNA or
DNA—is able to manufacture
RNA surrounded by a coat of
RNA from the DNA.
packed protein units called
capsomeres.
• No cell wall
• Cell wall
• Can’t reproduce without a
• Can reproduce on its own.
living host. Takes over cell’s
machinery to produce more
viruses.
D.7.2
• Describe the different ways in
which antiviral drugs work.
Describe the different ways in which antiviral drugs work.
Well known viral infections
• Common cold
• Influenza (Including H1N1)
• HIV/AIDS
• Chicken Pox
• Herpes/warts
What is the body’s natural defense to viral
infections?
Describe the different ways in which antiviral drugs work.
• Viruses multiply very quickly, so antiviral drugs
will often have little effect by the time symptoms
appear.
• Goal of antiviral drugs is to stop replication.
Describe the different ways in which antiviral drugs work.
• Acyclovir is used as a cream or orally to fight
herpes viruses.
• Shortens the time of the outbreak, but does
not prevent recurrences.
• It stops replication of viral DNA, and prevents
virus from multiplying.
Describe the different ways in which antiviral drugs work.
• Other antiviral drugs prevent new viruses
from leaving the cell.
• Amantadine (C10H17N) is used to treat
influenza. It inhibits the active site of an
enzyme which helps the virus to stick to the
cell wall.
D.7.3
• Discuss the difficulties associated
with solving the AIDS problem.
Discuss the difficulties associated with solving the AIDS problem.
• HIV (Human Immunodeficiency Virus) can lead
to AIDS (Acquired Immune Deficiency
Syndrome).
• HIV attacks white blood cells called T helper
cells (T4-cells).
• HIV therefore destroys the body’s ability to
fight infections, leading to common infections
(pneumonia, influenza) which can become life
threatening (AIDS).
Discuss the difficulties associated with solving the AIDS
problem.
• The virus is a retrovirus since is
contains RNA instead of DNA.
• It makes viral DNA from RNA using an
enzyme called reverse transcriptase.
• One of the problems with antiviral
drugs for HIV is the virus is constantly
mutating.
• A drug called AZT has been used to
inhibit the reverse transcriptase, and
this does not affect normal cells.
• AZT has been effective in prolonging
the period until AIDS develops.