Bacteria _ Viruses

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Bacteria _ Viruses Powered By Docstoc
					Viruses & Bacteria
 Read Chapter 5 packet ―Viruses and
  Bacteria‖ pages 105-115.
 In your science notebook…
    – Answer Section Review questions 1-5 from
      page 109.
    – Answer Section Review questions 1-5 from
      page 115.
    Viruses: What are they?
Viruses are strange things that straddle the
fence between living and non-living. If they're
floating around in the air or sitting on a
doorknob, they're inert. They're about as alive
as a rock. But if they come into contact with a
suitable plant, animal or bacterial cell, they
spring into action. They infect and take over the
cell like pirates hijacking a ship.
What is the Structure      A tiny particle of genetic
 of a Virus?                material (RNA and DNA) with
                            an outer coat of protein
                           Not living UNTIL they inject
                            themselves into a host (living)
                           May or may not have an outer
                            spiky layer called the envelope
                           Can attack animals, plants, and
                           Biggest viruses are only as
                            large as the smallest bacteria
What is the shape of a    Viruses come in all
 virus?                    different shapes
                          Some viruses are
                           shaped like a space
                           ship. They are called
How do viruses   1.   Virus injects itself into a
  reproduce?          living cell
                 2.   Protein coat is discarded
                 3.   Hereditary material takes
                      over the cell’s activities
                 4.   Virus reproduces and the
                      cell fills
                 5.   Cell splits open
                 6.   Viruses leave the cell and
                      attack new cells
   Example of Virus Reproduction
                                                            2. Bacteriophage
                                                               cuts a whole in
                                                               the cell wall
                                                               and injects
                                                               material. The
1. Bacteriophage landing on E.coli                             bacterial cell
   bacterial cell                                              begins making
                                                               new viruses.

     3. The E.coli bacterial cell becomes so full of new viruses that it
        bursts open and viruses move on to infect other cells.
How are viruses        By direct contact with
  transmitted?          infected individuals;
                       By contact with
                        contaminated objects (such
                        as toys, doorknobs)
                       By inhalation of virus-laden
                        aerosols. (think sneezes)
                       By animals that act as hosts
What diseases are                 Flu, colds, HIV/AIDS, hepatitis,
                                   west nile, measles, herpes,
caused by viruses?                 shingles, chicken pox, monkey
                                   pox, polio, smallpox, ebola, and
                                   some cancers (epstein-barr) are
                                   just a few viruses that affect
                                   humans and animals

                                  Tobacco mosaic and cauliflower
                                   mosaic are viruses that affect
      The green is the virus
      that causes HIV.
How are viruses
helpful?           Transfer genetic material
                    from species to species
                    (allows for evolution)
                   Destroy harmful algal blooms
                   Infect and destroy bacteria
                   Reduce the amount of
                    carbon dioxide in the
 Algal bloom        atmosphere
How are viruses                    Cause disease and
harmful?                            death
                                   Affect plant yields
                                   Infect animals such as
                                    birds and cows so
                                    they cannot be used
                                    for food.

  Virus that causes Herpes.
How are viruses          Vaccines which
  treated?                prevent the host from
                          contracting the virus

                         Antiviral drugs which
                          treat the virus once

                         Let it run its course!
     Bacteria, what are they?
Bacteria are single-cell organisms so tiny
 that millions can fit into the eye of a
They are the oldest form of life on earth.
 Microbe fossils date back more than 3.5
 billion years to a time when the Earth was
 covered with oceans that regularly
 reached the boiling point, hundreds of
 millions of years before dinosaurs roamed
 the earth.
           What are they?
Bacteria are everywhere. There are more of
 them on a person's hand than there are
 people on the entire planet!

Microbes are in the air we breathe, the
 ground we walk on, the food we eat—
 they're even inside us!
             What are they?
Without bacteria we couldn't digest food.

Without us, they’d probably be just fine.

Without microbes, plants couldn't grow,
garbage wouldn't decay and there would be
a lot less oxygen to breathe.

In fact, without these invisible companions,
our planet wouldn't survive as we know it!
What are Bacteria?        Living organisms
                          Belong to Kingdom
                          Most numerous
                           organism on Earth
                           but also the simplest
What are the                May be heterotrophic or
characteristics of           autotrophic
bacteria?                   Autotrophic = makes
                             own food through
                            If heterotrophic they will
                             be either parasites or
                            Parasites = feed on
                             living material
                            Saprophytes = feed on
                             dead material
What is the structure      Bacteria have cell walls,
 of bacteria?               cell membranes,
                            cytoplasm, hereditary
                            material, and may have a
                            flagella, a whip-like tail
                            structure used to move

                           Bacteria may form an
                            endospore, a thick outer
                            coatings that protect it
What are the                      Come in three different
shapes of bacteria?                possible shapes

                                   Cocci = sphere shape
                                   Bacilli = rod shape
                                   Spirella = spiral shape

 Cocci                Bacill           Spirella
How do bacteria          Bacteria reproduce
  reproduce?              through binary
                          fission, they split into
                          two cells.
How are bacteria       1. Direct contact with
  transmitted?            an infected person
                       2. Contaminated food
                          or water
                          (Salmonella, E.coli)
                       3. Dirty objects
                       4. Infected animals
How are bacteria                 Terrorism
  harmful?                       Disease
                                 Tooth decay
                                 Food spoilage
How are bacteria          Antibiotics
  helpful?                Nitrogen fixing
                          Food
                          Tanning leather
                          Breaking down
                           waste products.
                          Digestion
What are diseases         Cholera, tuberculosis,
 caused by bacteria?       lyme disease,
                           pertussus, salmonella,
                           staph infections, strep
                           throat, leprosy,
                           tetanus, diptheria,
                           E.coli, flesh eating
                           (necrotizing fascitis)
                           and ricketts.
How do we treat            Antibiotic: A chemical
  bacterial infections?     substance that stops
                            the growth of some
                            micro-organisms such
                            as bacteria within the
                           Sterilization (heat),
                            Disinfectants and
                            bleach to kill bacteria
Salmonella bacteria         before they can infect
Bacteria consist of only a single cell, but don't let
their small size and seeming simplicity fool you.
They're an amazingly complex and fascinating
group of creatures. Bacteria have been found
that can live in temperatures above the boiling
point and in cold that would freeze your blood.
They "eat" everything from sugar and starch to
sunlight, sulfur and iron. There's even a species
of bacteria—Deinococcus radiodurans—that can
withstand blasts of radiation 1,000 times greater
than would kill a human being.
        Infectious Diseases
 Infectious Disease (Communicable
  diseases): Diseases transmitted among
  people by harmful viruses or bacteria.
 Host: An organism in which another
  organism lives and gets nourishment and
        Infectious Diseases
 Infectious Disease (Communicable
  diseases): Diseases transmitted among
  people by harmful viruses or bacteria.
 Host: An organism in which another
  organism lives and gets nourishment and
 How a human body responds…
Body Defenses:

1. Skin, mucous membranes and cilia
  (tiny hairs inside your nose!!).

2. Immune system (special cells called
  white blood cells that fight infection.)
     Body Response Continued
When invaders enter the body
1. Increase blood flow to the area (inflammation)
2. Body temperature rises (fever) to prevent
  growth of disease.
3. Production of white blood cells
4. Production of interferon a substance that is
  released when infected cells burst which warns
  cells of invasion.
5. production of antibodies
         Types of Immunity
Natural immunity: Protection present at
  birth that prevents people from getting a
Acquired immunity: Protection against
  disease that develops throughout a
Vaccines: Substances that increase an
  organism’s immunity to disease.
          Bacteria and Virus
       Comparison/Contrast Poster
   Using all materials available to you, design a poster that
    compares and contrasts bacteria and viruses. You will need
    to include the following information in your poster:
    – Structure: What is the physical make-up of bacteria and viruses?
    – Shape: What are the different shapes viruses and bacteria come in?
    – Reproduction: How do bacteria and viruses create new viruses and
    – Transmission: Discuss how the viruses and bacteria transmit disease
      to other organisms.
    – Diseases Caused: What are three diseases caused by each?
    – How treated:      What is done to cure disease spread by viruses
      and bacteria? Also, what can be done to prevent the disease and
      treat the symptoms?
    – Helpful/Harmful: Give examples of how both viruses and bacteria
      can be harmful or helpful.
   Include images/drawings where appropriate.
       Bacteria and Virus
Comparison/Contrast Poster Rubric
Categories                                          Points
Structure:                                          _____/5
Shape:                                              _____/5
Reproduction:                                       _____/5
Transmission                                        _____/5
Diseases Caused                                     _____/5
How treated:                                        _____/5
Helpful/Harmful:                                    _____/5
Neatness, Spelling, grammar:                        _____/5
Proper heading in right hand corner on back         _____/5
Turned in on time!                                  _____/5

                                              TOTAL _____/50