VIROLOGY

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VIROLOGY
(STUDY OF VIRUSES)
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VIRUS
Latin for poison or slimy liquid
Science Nerd Definition
A small subcellular form that is
1smaller than a cell
2not considered a "living organism
3virulent - can cause disease
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A Virus is an Intracellular parasite
invades living cells -
can only "live"(survive/reproduce) within that
cell
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Where do viruses come from?
Theories
Viruses may...
1...de-evolve from higher life forms
(Called Progressive Parasite Degeneration)
2...have started out at the same time as cells
3...be escaped genetic material
(or extra parts of a chromosome)
This means that PERHAPS your body can make its
own
viruses!
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Properties of Viruses
(what they look like and other stuff like that!)
consist of DNA..
..or RNA
never both..
Size
smaller than smallest bacteria cell
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(Properties of viruses, continued)
Shapes-
brick,cylindrical,oval
..or may have more complicated structures almost
like ROBOTS
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(virus shapes, continued..)
Polio
Rabies
Ebola
Rotavirus
Influenza
Hepatitis
Early Italian scientists Thought this illness was
caused by the INFLUENCE of the stars And
planets..
Rhinovirus (common cold)
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Rabies
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Polio
Dr. Jonas Salk 1914-1995
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Influenza
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Ebola
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Smallpox
Edward Jenner
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How do viruses (most) attack cells and make us
sick??
Lets use the T4 bacteriophage as an example
T4 bacteriophage is a virus that looks a lot
like an alien landing pod------gt
With its six legs, the bacteriophage attaches to
the surface of the much larger bacteria
Escherichia coli (E. coli).
Once attached, the bacteriophage injects DNA into
the bacterium. The DNA instructs the bacterium
to produce masses of new viruses.
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So what happens to the bacterium?
So many new baby viruses are produced
that the E. coli BURSTS!!
This process of bursting is called LYSIS.
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Here's what an actual population of E. coli looks
like as it is wiped out by T4 bacteriophage
Now THATS a NASTY virus!