Transcript No Slide Title

VIRUSES
(What the heck are they?)
The Common Cold Virus
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Oh Goodness, My E. coli has a Virus!
Viruses and Bacteria
It's easy to mix these up since compared to us, both are
VERY SMALL.
Great link for size comparison!
Source: http://www.cellsalive.com/phage.htm
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The basics  Viruses are:
 non-living
 much smaller than the smallest cell
 pieces of genetic coding (DNA or RNA)
“gift-wrapped” in a protein coat
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Diversity of Capsids
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Diseases caused by viruses include:
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Common cold
Flu
Polio
Rabies
Herpes (chickenpox,cold sores, genital)
Warts
Measles, Mumps
Ebola
AIDS
Viruses cannot be killed with antibiotics because they are not alive!
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Antibodies attacking AIDS Virus
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Diversity of Life
Introduction to Prokaryotes
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Figure 13.27a
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Figure 13.27b
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Prokaryote Diversity
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• Two types of Prokaryotic organisms:
Eubacteria (bacteria) and Archaea
Prokaryotes
Domain Bacteria
Domain Archaea
(e.g., extremophiles)
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Visual Summary
Archaea – Thermophiles in a Nevada geyser.
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Archaea in a hot spring.
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Archaea – Halophiles
in seawater evaporating
ponds near San
Francisco Bay.
Salinity increases from
3% to 20% during the
production of salt.
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Archaea
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(a.k.a. “Archaeabacteria)
 Prokaryotic (like eubacteria)
 Biochemically resemble eukaryotic cells
 Believed to be the ancestors of eukaryotic cells
Today: only live in harsh environments
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(Bacteria Review)
What do you already know about
bacteria??
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Bacteria on the tip of
a pin.
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• Major Episodes in the History of Life
Millions of years ago
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570
1,000
1,700
2,500
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Major Episode
Plants and fungi colonize land
All major animal phyla established
First multicellular organisms
Oldest eukaryotic fossils
Accumulation of atmospheric 02
Oldest prokaryotic fossils
Origin of Earth
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Visual Summary
ALL CELLS have
• Plasma membrane
• DNA
• ribosomes
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Generalized structure of bacteria cell
Figure4.5x2
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Bacterial shapes: cocci, rods, spirals
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Cyanobacteria or “blue-green algae”
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Bacterial colonies growing in culture.
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Detriments to Humans
• Bad breath, tooth decay
• Food poisoning
• Some are pathogenic
pathogenic –
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Some Diseases caused by bacteria
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Strep throat
Cholera
Tubercolusis
“the plague”
Anthrax
Toxic shock syndrome
Syphilis, Gonorrhea,
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How cure bacterial infections?
(Antibiotics)
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Discussion Question:
Should we drop “bacteria bomb?”
• Are there benefits to
bacteria that outweigh
their detriments to
humans????
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Benefits of Bacteria
• Decomposers!  chemical cycling
• Cyanobacteria were original producers of oxygen
atmosphere  ozone
• Origins of mitochondria & chloroplasts
• Aid humans in digestion (E. coli)
• Allow cows to digest cellulose (grass)
 milk, ice cream, hamburgers!
• Lactic acid fermentation
(yogurt, buttermilk, sauerkraut)
• bioremediation
• Nitrogen “fixers”
(to be explained in Unit IV!)
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