Transcript Viruses and Bacteria What are they and how they affect us?

Viruses and Bacteria
What are they and how
they affect us?
By: Suzanne Huopalainen
Chamberlain High School
Biology
VIRUS
A virus is a nonliving, infectious agent made of nucleic
acid and protein coat
DO NOT HAVE
1. Nucleus, membrane or cellular organelles.
2. Does NOT eat, or respire
3. Does NOT reproduce
A virus is very tiny compared to even the
smallest cell.
Example: AIDS virus (in blue) 
attacking a T-cell.
PARTS OF A VIRUS
 Viruses are made up of 2
main parts.
 Protective Protein Coat =
CAPSID
 Nucleic Acid = DNA or RNA
 Additional protective coating
made of lipids, proteins, and
carbohydrates = ENVELOPE
 Spike like projections or tail
fibers – used to recognize
and bind to sites on
membrane of cells.
Example of HIV Structure
Virus Replication
1. Cannot Replicate on their own.
2. Must have a HOST: an organism
that shelters and nourishes
something (cell).
3. 2 Types of Replication
 Lytic Cycle –
 Lysogenic Cycle -
Viral Replication:
• Virus invades host cell.
• Replicates immediately.
• Host cell breaks apart or
lyses. (kills the cell)
• Viruses are released.
• Enter other cells and
repeats cycle.
Viral Replication -
Does NOT kill immediately.
Viral DNA inserted into
bacterial cell
chromosomes called
prophage.
Host cell carries prophage,
divides, replicating
prophage.
Stimulus  separation of
prophage and enters lytic
cycle.
Making a Vaccine
Directions:
1. Go to Internet Explorer.
2. In the address box type in the following address:
http://www.pbs.org/wgbh/nova/meningitis/
3. Press Enter.
4. Click on “Making Vaccines” by the cow picture.
Click on Making Vaccines (244K)
Requires Flash
Making Vaccines Cont’d
 Read through all instructions on the “Making
Vaccines” introduction page. It will explain to you
how to use the program and how to complete each
vaccine.
 Continue through the program by selecting the six
pathogens at the top. Starting with the pathogen
on the LEFT first, and work your way to the right.
For each pathogen answer the following questions
below on a separate sheet of paper.
Vaccine for Smallpox:
1.
2.
3.
4.
5.
6.
7.
8.
When creating a vaccine that will protect you against a
certain pathogen, you usually begin with that pathogen and
alter it in some way. How is smallpox different?
What virus is used that is similar to smallpox?
How is the virus collected?
What is step one?
What is step two?
Why is step two necessary?
What is step three?
How will this vaccine benefit your body?
Vaccine for Measles:
1. What is step one the purpose of it?
2. What does the tissue culture act as for the
virus?
3. Why is the culture kept at a low temperature?
4. Why are the strains that have a more difficult
time growing in the warmer environment of
the human selected?
5. How many years did it take to create the
measles vaccine?
6. List four other diseases that live-attenuated
vaccines prevent against.
Vaccine for Polio Virus:
1. What is the goal of creating a killed vaccine?
2. What is step one?
3. What is step two?
4. List two ways to inactivate a virus or bacteria used
in a vaccine.
5. What was used in step three to inactivate the
virus?
6. Why are booster shots necessary for certain
vaccines?
7. Name four diseases that are prevented by killed
vaccines.
Vaccine for Tetanus:
1. What is Tetanus?
2. What is the goal of a toxoid vaccine?
3. What is step one?
4. For step two, what must be done to produce the
vaccine?
5. What is used in step three to neutralize the toxins
so they are less harmful to humans?
6. What was used in the Polio vaccine to inactivate
that virus?
7. What is an “adjuvant?”
Vaccine for Hepatitis B
1.
2.
3.
4.
5.
6.
7.
8.
9.
Give an example.
What technique is being used for this vaccine?
The part of DNA removed is responsible for what
gene?
What is the viral segment of DNA added to?
This technique is also known as making
____________________ DNA.
The vaccine will stimulate the immune system to
attack the ________________ (protein coat).
Is the Hepatitis B Antigen harmful in anyway? Why?
What other virus is prevented by the use of a subunit
vaccine?
What is a subunit vaccine?
Vaccine for AIDS:
1.
2.
3.
4.
5.
6.
7.
8.
What is the goal of genetic vaccines?
What does PCR stand for?
What is step one?
What is a vector?
How do you splice a gene from a virus to a vector?
What is step three?
What technique is used to separate the vectors from
the bacteria?
What are four other diseases where human trials are
being performed using genetic vaccines?
Making Vaccines
Now let’s move on to the quiz!
VIRUS QUIZ
• Click on the picture below to begin
your quiz.
• GOOD LUCK!
KINGDOM MONERAN
Prokaryotes (Bacteria)
Main Characteristics
1. Prokaryotic – lack membrane bound
nucleus.
2. Have cell membrane
3. Smallest living organism
4. Unicellular
5. Contain plasmid – 1single double
stranded circular chromosome.
LIFE CYCLE
• Reproduce every 20
minutes
– Makes it easy to adapt
and change to harsh
conditions.
• Form endospores –
dehydrated cell that is
alive but inactive.
– Waits for favorable
conditions to
reproduce.
REPRODUCTION
• Asexually –
through binary
fission.
– Chromosome
replicates after
cell divides = 2
identical cells.
– Enables quick
reproduction.
Reproduction Cont’d
Sexually – 2 ways
Transformation – bacteria
take up pieces of DNA
from environment (nearby
bacteria that died)
Conjugation – 2 bacteria
cells join and transfer
genetic material between
them.
Bacteria Webquest
• Click on the picture to
the right to go to the
Web Quest.
• Print a copy of the page
before you begin.
• Answer all questions by
following the directions
and using the websites
provided.
HELPFUL BACTERIA
• Form symbiosis relationships with other
organisms.
• Ability to decompose: breakdown and
recycle C,N, and S.
• Ability to restore environmental conditions
(breakdown bad chemicals)
• Extract Minerals
• Ability to produce foods and medical
products.
BAD Bacteria
• Bacteria can cause diseases and
sickness.
– Enters through air, food, and water.
– Examples
•
•
•
•
•
Tuberculosis
Anthrax
Lyme disease
Toxic Strep
Cholera
Fighting Bacterial Diseases
• Use of antibiotics:
medicine that kills or
slows the growth of
bacteria.
• Read the article
• Jack’s “Bugs in the
News” – What the
heck is penicillin?
• Answer the questions
of the next slide.
What the Heck is Penicillin?
• How does penicillin kill bacteria?
• Why do you think it is a good thing that
antibiotics like penicillin exist?
• What do you think it was like before they
existed?
Classification of Bacteria
• Bacteria belong to
the Kingdom
Monera
• 2 Main Groups
– Archaebacteria
– Eubacteria
Borrelia burgdorferi
Archaebacteria
Bacteria found in
extremely harsh
conditions
Consider ancient
bacteria
Resembles life on
Earth during harsh
conditions
4 types –
Methanogens,
Thermophiles,
Psychrophiles and
Halophiles
3. Ice
2. Hot
Geysers
1.Sulfurous
Lakes
4. Utah’s
Great Salt
Lake
5. Hydrothermal
Vents
Types of Archaebacteria
Subtype of
Description
Archaebacteria
1.Methanogens
Lives in Oxygen free
environments. (Digestive
tracts, swamps, and sewage
plants)
Methanopyrus
2. Thermophiles
Lives in extremely hot
conditions
(60degrees C  250 degrees
C)
Pyrodictium
3. Psychrophiles
Lives in extemely cold
conditions (Arctic)
4. Halophiles
Live in salty conditons
Halobacteria
Pictures
EUBACTERIA
“True Bacteria”
• Classified by
– Shape
– Cell wall composition
• Gram (+) or Gram (-)
– Nutrition – autotrophic or
heterotrpohic
– Respiration – aerobes (use
O2) or anerobes (no O2)
Three Shapes of Bacteria
COCCI – round,
circular shape
bacteria.
BACCILLUS – rod
shaped bacteria.
SPIRILLA – spiral
shaped bacteria.
Inhabits the throatcauses Strep
Soil Bacteria
Survives strong
acidic conditions in
stomach
Cell Wall Composition
Two types of cell walls
Composed of peptidoglycan
Less peptidoglycan and an
additional outer
membrane.
Determined by testing
method called
GRAM STAINING.
GRAM POSITIVE BACTERIA
GRAM NEGATIVE BACTERIA
GRAM STAINING
•Gram-positive bacteria retain the violet
dye.
•Gram- negative have an extra lipid layer
(Prevents many antibiotics from entering
the cell)
–Takes on a pinkish color.
Alternative Assessment
Center of Disease Control
Outline for Disease Notification Assignment
• Task: You have recently received an assignment,
from the Center of Disease Control. As a member
of the Public Health Notification Service (PHNS)
your job is to make our citizens in the United
States aware of existing diseases. Each member
of the PHNS has received an assignment, where
each member is responsible for one disease.
Center of Disease Control
The CDC wants an array of posters to be
designed, providing information on specific
diseases. Each poster will contain:
1.
2.
3.
4.
5.
6.
The Name of the Disease or Sickness
Symptoms and Affects of the Disease
Cures and Preventions
The Organisms’ or Virus’ name which
causes the disease.
If an Organism - the Kingdom
and Phylum it may belong to.
If a virus - is it DNA or RNA related.
7. Three characteristics about the
disease-causing organism.



8.
Is it Prokaryotic or Eukaryotic?
Is it Heterotrophic or Autotrophic?
What type of vaccine is used, if any
to prevent it?
Are there any main carriers of the
disease?


Other organisms?
Locations that they are found in.
9.
How is it transmitted or contracted?
10.
Illustrations – Pictures and
Diagrams
Center of Disease Control
The CDC wants posters to be informative,
attractive, and organized. They want to
provide information to the public that is easily
accessible and understandable.
The CDC, along with other members of the
PHNS, will be reviewing all the posters.
Presentation must be at least 1- 2 minutes
long.
Center of Disease Control
Examples
of
Posters
Center of Disease Control – Alternative
Assessment Rubric
THE END