Viruses and BacteriaWhat 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. 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?

2. What virus is used that is similar to smallpox?

3. How is the virus collected?

4. What is step one?

5. What is step two?

6. Why is step two necessary?

7. What is step three?

8. 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. Give an example.2. What technique is being used for this vaccine?3. The part of DNA removed is responsible for what

gene?4. What is the viral segment of DNA added to?5. This technique is also known as making

____________________ DNA.6. The vaccine will stimulate the immune system to

attack the ________________ (protein coat).7. Is the Hepatitis B Antigen harmful in anyway? Why?8. What other virus is prevented by the use of a subunit

vaccine?9. What is a subunit vaccine?

Vaccine for AIDS:

1. What is the goal of genetic vaccines?

2. What does PCR stand for?

3. What is step one?

4. What is a vector?

5. How do you splice a gene from a virus to a vector?

6. What is step three?

7. What technique is used to separate the vectors from the bacteria?

8. 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 MONERANProkaryotes (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 Ne

ws” – 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

1.Sulfurous Lakes

3. Ice

2. Hot Geysers

5. Hydrothermal Vents

4. Utah’s Great Salt Lake

Types of Archaebacteria

Subtype of Archaebacteria

Description Pictures

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

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. Survives strong

acidic conditions in stomach

Soil Bacteria

Inhabits the throat- causes Strep

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. The Name of the Disease or Sickness

2. Symptoms and Affects of the Disease

3. Cures and Preventions

4. The Organisms’ or Virus’ name which causes the disease.

5. If an Organism - the Kingdom

and Phylum it may belong to.

6. If a virus - is it DNA or RNA related.

7. Three characteristics about the disease-causing organism.

Is it Prokaryotic or Eukaryotic? Is it Heterotrophic or Autotrophic? What type of vaccine is used, if any

to prevent it?

8. 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