bacteria, archaea , viruses
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Bacteria, Archaea, Viruses
Which Kingdom do Viruses belong to?
Bacteria
• Single cell – unicellular• Prokaryotes – no nucleus, no organelles• DNA – circular - single loop + has many
plasmids• Cell Wall – not rigid like in plant, more flexible
– composed of peptidoglycan– can protect bacteria from hosts defenses– useful as a signal to other bacteria
Bacteria Structure
5. Nucleoid region contains a circular loop of DNA
6. Plasmids are rings of DNA, used in reproduction
7. Ribosomes in cytoplasm synthesize proteins
2. Flagella is used for movement
3. Pilli (Fimbrae) help bacteria cling to surfaces
4. Prokaryotes do not have organelles or a membrane bound nucleus!
How do Bacteria Obtain Food
PhotoautotrophsChemoautotrophs
Heterotrophs
Photoautotrophs - cyanobacteria
Chemoautotrophs - sulfur-loving bacteria
• need CO2 as a carbon source
• obtain energy NOT from light
• obtain energy from oxidization of H2S, HN4, or Fe+
Heterotrophs
• Obtain their energy from organic compounds
• These are made by the photo- and chemo-autotrophs
Disease causing Bacteria• Cholera• Anthrax• Tuberculosis – TB• Pneumonia• Tetanus• Streptococcal diseases• Variety of infections – assosiated with other
diseases (post-operative, cold and flu- associated, etc.)
Archaea – ArchebacteriaAncient Bacteria
• At first believed to be weird bacteria• Scientific evidence tell us that they are very,
very old organisms – share characteristics with bacteria , BUT also characteristics with eukaryotes
• Life in EXTREME environments – places on Earth where they are the ONLY living thing
Archeae
• Unicellular prokaryotes (like bacteria)• Have a cell wall (like bacteria) BUT cell wall is
very different composition• Cell membrane is so different from bacteria
that antibiotics (which kill bacteria by affecting cell wall and membrane) have NO effect on archaebacteria
Origins
Archaea of Note• Lobus fulgidus is a sulfur-reducer that can sour oil
wells. • Halobacteria are salt-loving microbes that give a
pink tinge to salt water evaporation ponds, the Dead Sea and salted fish.
• Pyrolobus fumarii led scientists to extend the upper temperature limit for life to 113 degrees Celsius (235.4 degrees Fahrenheit).
• Sulfolobus acidocaldarius is used to leach copper and iron from ore.
Where do they live?
Ocean Vent
ice
sulfur Great Slat Lake
Geyser
THERMOACIDOPHILE – the red stuff on the rocksThis is an archaebacteria.
THE FUTURE//PAST BELONGS TO ARCHAE!
How weird can they get?
• Thermophiles like unusually hot temperatures. A few species have been found to survive even above 110 degrees Celsius (water boils at 100 degrees Celsius).
• Psychrophiles like extremely cold temperatures (even down to -10 degrees Celsius).
• Halophiles thrive in unusually salty habitats. Some can thrive in water that’s 9% salt; sea water contains only 0.9% salt.
• Acidophiles prefer acidic conditions; Alkaliphiles prefer very alkaline environs.
What do they Eat
• Hydrogen Gas• Carbon dioxide• Sulfur• sunlight – autotroph – light-harvesting
pigment in cell membrane
What is a virus?• A nonliving particle made of
protein, nucleic acids and sometimes lipids
• Viruses can only reproduce by infecting living cells!
• Viruses are parasites!
Viral Structure• Capsid-the protein coat
surrounding a virus
Viral Structure• Capsid can be different shape
and form• Bacteriophages –Viruses that infect bacteria
Viral Infections• Lytic Infection-
–Virus enters a cell–Makes copies of itself–Causes the cell to burst or lyse– Can the virus keep doing
this?
Viral Infections• Lysogenic Cycle
–Virus enters cell–Prophage- viral DNA embedded
in the host cell’s DNA–Virus is dormant – lays low
Virus Genetic material
• DNA Viruses and RNA Visruses
• Both types can have ss or ds DNA/RNA
• Some RNA viruses have enzymes that convert their RNA into DNA
Retrovirus• The genetic information is
copied from RNA to DNA instead of from DNA to RNA
• Example: HIV
Some Viral Diseases• Common Cold – many different viruses –
rhinoviruses (RNA), corona viruses, etc.• Flu – Influenza (RNA) virus• AIDS – HIV• Measels – Paramixovirus• Cold sores – Herpes virus• Mumps – Paramixovirus• many, many others
Some exotic ones
• West Nile fever – west nile virus• Hemorrhagic fever – many nasty viruses:
Ebola, Marburg, Lassa, Dengue, etc.• Tick-bore encephalitis – TBEV• 4-corners disease – Hanta virus (Hantavirus
Pulmonary syndrome)• More exotic ones appear – they jump hosts –
destruction of Rainforest??????
Outbreak Movie Trailer
Contaigon Movie Trailer
Useful Bacteria
• Many Bacteria are beneficial to humans, animals, plants, the environment – more and more bacteria are used to do strange things
• Check this out: Weird uses of Bacteria
Probiotics• Bacteria and yeast that are believed to
improve health• Available in certain foods or as supplements• Our digestive system is home to more than
500 different types of bacteria – keep intestines healthy and help with digestion, help immune system
• Probiotics may help treat several digestive disorders – Diarrhea, Colitis, Irritable Bowl syndrome, etc.
Probiotics
Auditions for Helpful Bacteria
And the winner is ........
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