Transcript Bacteria and Viruses

Our Microscopic World
 smallest, simplest organism, unicellular
 Most abundant organism
 Prokaryotic cell…very simple, NO nucleus, ribosomes,
cytoplasm, circular DNA, cell membrane, some have
cell walls
Archaebacteria
 “old” bacteria
 Found in inhospitable
conditions
 Three types
1. Heat lovers…found in hot
springs, paint pots, ocean
vents
2. Methane makers…found in
swamps
3. Salt lovers…found in high
salt environments…ie: Dead
Sea
Eubacteria
 Most common
 Found everywhere
 Grouped by how obtain
food
1. producers…make own
food
2. decomposers…consumer
that breaks down matter to
obtain nutrients
3. parasites…consumer that
obtain nutrients by feeding
off other organisms
SHAPES
1. COCCI…Sphere
shaped
2. BACILLI…bar
shaped
3. SPIRILLA…spiral
shaped
Bactria Reproduction… Binary Fission
Bacteria reproduce in a
process called BINARY
FISSION
1. Cell grows larger
2. DNA replicates
and attaches to the
cell membrane
3. The DNA and its copy
separate as the cell
grows larger
4. The cell splits in two.
* each new cell
contains identical
DNA
For MOST bacteria…Ideal conditions for
reproduction are warm and moist.
When conditions are not ideal, some will
survive by forming and ENDOSPORE, a
hard protective covering. Many bacteria
can survive boiling, freezing, and
extremely dry conditions. When
conditions become favorable again,
endospores can break open and bacteria
can become active again.
Nitrogen Fixing Bacteria…
takes nitrogen from the air and change it to a useable
form plants can use
Decomposing Bacteria…
breaks down dead matter so nutrients are available for new
plants
Bioremediation…
bacteria converts pollution into harmless chemicals …
used to clean up wastes, oil spills and remove toxins from
soils
Genetically Engineered Bacteria…
To produce…
medicine, insecticides, cleaners, adhesives and some
foods
Medicines such as…
 ANTIBIOTICS…chemicals used to kill
bacteria and other microorganisms
 INSULIN so diabetics are able to process
sugars and carbohydrates
Foods… (BLANK)
to help make some sausage, some dairy products
(cheese/yogurt/cottage cheese, etc), pickles
Pathogenic Bacteria (Cause disease)
 They invade the host and obtain nutrients from
the host, weakening the host and causing damage
to the host
 Most can be treated with ANTIBIOTICS
Human Diseases caused by Bacteria…
cavities, ear infections, strep throat, food
poisoning
Can cause disease in animals but also in plants,
protists, fungi and other bacteria!
Particles that imitate life…
 Microscopic particle that invades a cell, often
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destroying it
Found everywhere
Many diseases are caused by viruses
Contains a protein and nucleic acid (genetic
material)
DO NOT eat, grow, use air
Can only reproduce with HELP from a host
The are NOT living!
Viruses are classified in many ways…
 Type of disease
 Life cycle
 Type of genetic material
 Shape
Crystal…ex: polio virus
Cylinder…ex: tobacco
mosaic virus
Spherical…ex: influenza, HIV
Spacecraft…ex:
bacteriophage
VIRAL REPRODUCTION
 Viruses MUST have a host to
reproduce
 The reproduction process is
the LYTIC CYCLE
A. Virus finds a host cell
B. Virus enters cell OR DNA
is injected into cell
C.
Virus’ DNA takes over
control of the cell
D. Cell produces new viruses
E. New viruses break out of
the cell and invade other
cells
 Common cold
 Influenza
 Polio
 Chicken pox
 Measles
 Mumps
Vaccines are used to build up an individual’s immune
system by…
1. Inject a weakened or “dead” virus into the body
(the shot)
2. The body’s immune system recognizes the invader and
begins to build up antibodies (an army) to fight the virus
3. The body’s immune system is able to build up the antibodies to
fight the virus because the virus is not very strong.
4. The next time the virus in introduced into the body, the body
recognizes the virus and already has the antibodies (army)
to fight the virus.
Common vaccines: polio, measles/mumps/rubella (MMR),
influenza, chicken pox, hepatitis
Non-infectious Disease…a disease that is not transmitted
from person to person
Infectious Disease…a disease that is caused by a
pathogen (bacteria, virus, fungus, protist) can
generally be transferred from person to person
 Microscopic organisms
 Found commonly in pond water
 Cause dysentery
 Don’t drink water from Mexico
 Cause fungal infections
 Yeast infections
 Athletes foot