Viruses%20%20

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Chapter 18
VIRUSES
Bacteria

• Viruses Bacteria

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Viruses

• NOT considered living therefore viruses are NOT
  placed into any kingdom
• Viruses are not cellular
• Viruses do not carry out respiration
• Viruses are non motile
• Viruses do not grow
• Viruses can not make proteins
• Viruses no metabolism or homeostasis

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Viruses

• Viruses are NON LIVING particles (sub cellular)
  that can reproduce only when in a living cell.
• Found basically everywhere ( Air, Water, Soil)
• Viruses are smaller than prokaryotes.
• Viruses can only be viewed w/electron microscope.
• Viruses are pathogens
• BACTERIOPHAGE is a special type of virus that
  infects only bacteria (bacteria eaters)

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Viruses

• Viruses even though they are non living are
  called parasites b/c they feed on lining things
• HOST CELL is a cell in which a virus reproduces
• REVERSE TRANSCRIPTASE is an enzyme that when
  injected into a host cell, it will copy viral RNA
  into DNA

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VirusLYTIC CYCLE

1. Virus attaches to a host cell.
2. Virus injects its nucleic acid into the host
   cell.
3. The host DNA is destroyed and the virual genes
   are copied.
4. New virus particles are assembled.
5. The host cell breaks open and the new virus
   particles are released.

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BACTERIA

• PROKARYOTE
• NO internal membrane organelles
• NO NUCLEUS
• CIRCULAR DNA
• Plasmid
• All bacteria are unicellular
• Some may colonize but are not multicellular as
  the activities of the cells of the colony are not
  specialized

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Bacteria

• KINGDOM
• Old five (5) kingdom hierarchy
• Monera
• New six (6) kingdom hierarchy
• Eubacteria
• Archaebacteria
• Scientists think 1st bacteria (anaerobic)

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BACTERIA

• When you are sick there is something in your body
  that makes you feel nauseous, what is it? Its
  bacteria. Bacteria are a germ that you cant see
  with the naked eye. You might not be able to see
  them but there are billions of them all over you.
  Sometimes bacteria are bad but sometimes it helps
  us fight infections. One form of bacteria causes
  bad breath. If your gums and teeth are healthy
  then the problem is your tongue. You might
  already know, but bacteria come in all different
  shapes and sizes. Typically there are three
  certain shapes of bacteria round, rod-shaped, and
  spiral bacteria. They are also classified into
  groups very specifically.

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BACTERIA

• Classified many different ways. One way is by
  shape
• Three basic shapes
• BACILLUS (rod)
• SPIRRILUM (spiral)
• COCCUS (sphere)

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Bacillus(rod)
Coccus (Sphere)
Spirrilum (Spiral)
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Typical bacterial Cell
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ArchaebacteriaExtremists

• Ancient ones
• Live in extreme environments
• Ribosomal RNA is different from Eubacteria rRNA
• Three types
• Grouped by where they live
• Marshes/sewage/digestive tracts some mammals
• Water w/high salt conc. Great Salt Lakes/Dead
  Sea
• Deep cracks in the ocean floor
• Autotrophic and/or Heterotrophic

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Archaebacteria
Unicellular Prokaryotes Form and Metabolism are
different than in any other organisms Found in
areas sheltered from evolutionary
alteration unchanging habitats Resemble earths
early environment living relics surviving
representatives of first ages of life on
earth Produce methane and cluster together as a
group No peptidoglycan (murien) cell wall Get
food by sunlight, organic compounds, and
inorganic compounds
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Eubacteria

• True bacteria
• Heterotrophic live almost everywhere
• Some are parasitic
• Some are saprophytes
• Some use organic molecules as their food
• Photosynthetic Autotrophs live in places
  w/sunlight
• Cyanobacteria introduced oxygen into the
  earths atmosphere
• Chemosynthetic break down and release the
  energy of inorganic cpds. w/sulfur nitrogen
• Convert atmospheric nitrogen into
  nitrogen-containing cpds that plants need.

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BACTERIA

• Unique cell walls
• Cell wall needs to stay intact.
• Penicillin kills bacteria by causing holes to
  develop in the cell wall

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BACTERIA

• How does a bacteriums
• cell wall protect it?
• The cell wall prevents water from entering by
  osmosis and causing it to burst

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Bacteria

• A. Where is the genetic material of a bacterium
  found?
• B. What structure do some bacteria use to move?
• A. As a plasmid or circular chromosome within the
  cells cytoplasm
• B. Flagella

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Bacteria more beneficial ones than pathogenic
ones

• Some Uses
• Farming
• Medical industry
• Food industry (Swiss cheese/yogurt/sour cream
  /vinegar/sauerkraut/ pickles
• Nitrogen fixation
• Recycle nutrients

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Good Bacteria

• Some of the good bacteria are in our stomachs,
  helping digest food. While others are important
  in the production of dairy products such as
  cheese, yogurt, buttermilk, and sour cream. Just
  remember that you can eat foods that have
  bacteria just as long as it's good bacteria

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Good Bacteria

• A researcher in Canada is trying to encourage
  the use of bacteria pesticides to grow on crops.
  Scientists at a university located in Winnipeg
  did some tests to see how this bacteria would
  effect the plants. After adding an exceptional
  amount of water they added bacteria that causes
  food poisoning. These bacteria include E. Coli
  and Salmonella. This prevented insects from
  eating the plants. This will also reduce the
  amout of chemical pesticides that could harm are
  ecosystem.

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Nitrogen fixing bacteria
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Bacteria - uses

• Nitrogen fixation Most of the Earths nitrogen
  exists in atmospheric gas form. 80 of the
  Earths atmosphere
• All organisms need nitrogen but very few can use
  it directly from the atmosphere.
• Several species of bacteria have enzymes that
  convert atmospheric nitrogen into ammonia
• Some bacteria convert the ammonia into nitrites
  and nitrates
• Plants then use the nitrites/nitrates
• ONLY bacteria can carry out these processes

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BacteriaSome evolutionary adaptations in
bacteria

• Reproduce Rapidly by BINARY FISSION
• High rate of mutation
• Exist in Adverse conditions
• Can utilize substances harmful to other organisms
• Simpilcity of the cell structure
• Some are aerobic
• Some are anaerobic
• Some are facultative aerobes (both w/wo oxygen)
• Some are obligate anaerobes w/o oxygen
  release energy by fermentation

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Bacteria

• Some can carry out Nitrogen Fixation a process
  by which bacteria convert nitrogen gas
  (atmospheric nitrogen) into ammonia.
• Reproduction
• Commonly Binary Fission (asexual)
• Conjugation (sexual) may occur as well is a
  simple form of reproduction. Conjugation brings
  about an exchange of genetic material between
  bacterial cells allows for diversity

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Why cant bacteria reproduce by mitosis or
meiosis?

• B/c they do NOT have a nucleus, and instead of
  pairs of chromosomes they have one circular
  chromosome and varying numbers of smaller
  circular pieces of DNA called plasmids.

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Bacteria

• Bacterial reproduction can occur rapidly every
  20 minutes by binary fission.
• Why does this not occur?
• They would cover the surface of the Earth within
  a few weeks. They would run out of nutrients and
  water, they would poison themselves with their
  own wastes

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Bacteria

• ENDOSPORE structure in some bacteria that is
  resistant to adverse environmental factors
  (protects the bacteria)
• ENDSPORE bacterial form that is in a state of
  slow metabolism and that does not reproduce.
• ENDOSPORES may be harmful to other organisms.
  C.botulinum endospores will produce toxins and
  result in causing botulism in other organisms
  (deadly food poisoning)

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Most Common Bacteria

• Escherichia Coli
• E coli is a very common Actually it is the most
  common species of bacteria. Theodore Escherich
  discovered the bacteria, E. Coli. This bacteria
  does not have one particular environment that it
  lives in. It could be found in places such as hot
  springs and radioactive wastes. E. Coli also live
  in the intestine and help to break down food

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Bad Bacteria

• Bacterial Meningitis is an infection that affects
  the lining of the brain and the spine. There have
  been reports about this disease causing death
  lately, but this illness can be treated if it is
  found early. It can be caused by bacteria,
  widespread virus, and chemicals. Bacteria forms
  of Meningitis are more serious. This bacteria can
  get into your bloodstream. If you dont treat it
  then it could cause paralysis, severe brain
  damage, and damage to other organs.

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• Salmonella is another type of bacteria.It is
  commonly found in poultry, eggs, meat, and
  water. If you have a pet turtle or bird they may
  carry it. It attacks the stomachand intestines.
  To keep from getting Salmonella you should wash
  your hands after touching anything that might
  carry Salmonella.

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Bacteria

• TOXIN poison produced by some bacteria
• Food poisoning (both salmonella/botulism)
• Some bacteria are pathogenic
• Streptococcus pneumoniae causes pneumonia
• Name tells you that the bacteria are arranged as
  long chains of round cells (coccus-sphere shaped
  or round)
• Gonorrhea. Syphilis/Tuberculosis/
  Diphtheria/Tetanus

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Bacterial Food Poisoning

• Fungi, viruses, and bacteria can cause food
  poisoning however, bacteria related food-borne
  illnesses are the most common. Bacteria usually
  develops on raw foods. Remember it is a
  decomposer and it breaks down material as it
  feeds on it. If you dont cook your food
  thoroughly then you allow bacteria to grow and
  spread on your food