The Virus Structure Virus Reproduction The Lysogenic Cycle
Transcript of The Virus Structure Virus Reproduction The Lysogenic Cycle
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The Virus & The BacteriaThe Virus
� 20nm-60nm
� Not considered alive.
� Can only reproduce
inside the Host Cell.
� Specific – Attach only
to specific cells based
on the proteins in the
cell membrane.
The Virus Structure
� Made up of
� Nucleic Acids –
containing either, DNA
or RNA.
� Capsid- a protein coat
that surrounds the
Genetic material.
Virus ReproductionThe Lysogenic Cycle
Virus ReproductionThe Lytic Cycle
Virus Reproduction
� The Lysogenic Cycle
� Do not destroy the host
cell at first.
� Continue to reproduce
with the virus Genetic
Material inside.
�The Lytic Cycle
�Virulent virus
�Direct Death of the Host cell
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Hemorrhagic Fever
Ebola Marburg
Hemorrhagic FeverEbola
� Found in Primates
� Animal-Borne Virus
� RNA virus
� Incubation – 2-21 days
� Fever, headache, joint & muscle pain – rash
red eyes – Bleeding from all orifices.
Ebola
� Transmission – 1st patient
comes in contact with the
infected animal.
� Direct contact with blood
and/or secretions.
� Ebola Reston – airborne only
in monkeys
� Hot zones – Congo, Gabon,
Sudan
SARSSevere Acute Respiratory Syndrome
Hot Zone- China, Toronto
Symptoms – Flu like- fever,
headache, dry cough
Transmission- Person to
person contact, respiratory
secretion
Military action has been
taken to keep virus
controlled.
Small Pox
� Spans 1,000’s of years.
� 30% fatality rate
� 100% fatality rate in
the flat & hemorrhagic
strains.
� Eradicated from the
world
� Last U.S. case 1949
� World case -1977
Small Pox
� Humans are the natural host.
� Spread by face to face contact. – Also body fluids.
� Most Contagious during Early Rash continues till the last scab falls off.
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Small Pox
� Feared to be used as a
Biological Weapon
� Known vials Siberia,
Atlanta
� Believe – India,
Pakistan, China, Israel,
Iraq, North Korea, Iran,
Cuba, Taiwan, Former
Yugoslavia, France, Al-
Qaeda, Aum Shinrikyo
Small Pox
� Historical Facts
� The first urban Virus - arose 7,000 years ago in
large cities. Why?
� Pharaoh Ramses V – died of the pox
� Chinese worshiped the goddess of small pox
named T’ou Shen Niang-Niang
� India – the goddess what Shitala Ma
HIVHuman Immune Deficiency Virus
� Fastest Spreading
disease in Africa
� Effects white blood
cells. T-Cells
� T-cell count below 200
you have AIDS.
� Blood Tranmission
West Nile Virus
� Host – Birds
� Spread through mosquitoes
� Fever, headache, and body
aches, occasionally with skin
rash and swollen lymph nodes.
� Rare encephalitis
� 1% of mosquitos carry the
virus, 1% of those infected
will die.
The Bacteria
� Prokaryotic Cells
� Two Kingdoms
� Archaebacteria - The
extremists. 3 types
� Lives in Oxygen free environments
� High salt content
� Hot acidic waters
� Eubacteria
Bacteria-Eubacteria
� Many varieties
� Heterotrophic
� Saprobes – feed off the dead.
� Photosynthetic
� Chemosynthetic autotrophs - feed
off the break down of inorganic
substances. Reproduce Sexually
� Reproduce asexually – fission
� Reproduce sexually
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Reproduction – Genetic Recombination
� 1. Transformation – When a bacteria
transfers a piece of its DNA into another
bacteria creating a slightly different genotype
and phenotype.
� 2. Conjugation – when two bacteria form
pili between one another transfer genetic
material.
Bacteria - Structure
� Different Shapes
� Sphere - coccus
� Rods - bacillus
� Spirals – sprillium
� Structures
� Capsule
� Cell wall
� Plasma membrane
� Pili
� DNA
� Flagella
Antibiotics only Kill
Bacteria
Anthrax
� Direct contact
� Many different strains
� Found in lower vertebrates –
goats, sheep, cattle
� Three types
� Cutaneous – skin – death rare if
treated
� Inhalation – Cold-like – fatal
� Gastrointestinal – 25-60%
Flesh Eating Necrotizing Fasciitis
• Group “A” Streptococcus
with a mutation.
• Reproduces rapidly
• Tissue must be removed.
• Patient must be put into a
pressure chamber to
reduce the spread.
Bubonic Plague or Black Death
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Bubonic Plague or Black Death
� Swollen lymph nodes
(buboes, hence the
name), high fever, and
delirium.
� 90% Death Rate
� Killed 137 million
people
Lyme Disease
• Host is the Deer tick.
Botulism & E. Coli
• Botulism
• Muscle-paralyzing disease.
• Food-borne
• Anaerobic
• E. Coli
• 1,000 of strains
• Undercooked meat
• Sewage water
• Lives in intestines.
Bacteria can be
Good
Nitrogen Fixation
Nitrogen gas is changed
into a usable form to
make proteins, DNA,
RNA, & ATP
Found in the roots of
Legume plants .
Food Source
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Decomposer