1. Ms. Stroup 8th Grade Science Microbiology
Viruses and Bacteria
Ms. Stroup
8th Grade Science
Microbiology

2. Warm-Up
Pretend you went to a foreign country where people knew nothing about infectious diseases. You notice people are infected with influenza.
Q)How would you explain to someone what the flu is, how they got it, and what it is doing to their body?
(Only write the question)

3. Viruses

4. Viruses
Viruses are NOT classified as organisms because they are NOT free-living cells
They need a host cell to live and reproduce
They are composed of nucleic acid (DNA or RNA) and a protein coat.

6. How viruses make you sick..
Viruses invade healthy cells and use the enzymes and organelles of the host cell to make more viruses.
This usually kills the host cell in the process

7. Viral Replication- Lytic Cycle
The virus attaches itself to the cell membrane of a host cell.
The virus (or its genetic material) penetrates the cell.
The enzymes in the host cell uncoats the virus’ capsid.
The virus’ genetic material is released into the host cell and begins to make copies in the cells nucleus.
New genetic material is enclosed in a new capsid, and a copy of the virus is released out of the cell membrane…ready to invade a new healthy cell.

8. Viral Transmission Human Contact or insect bite
Viral diseases are the most widespread illness in humans.
Diseases can range from being mild like the common cold to sever and fatal diseases like cancer or HIV/AIDS.

9. Prevention/Treatment
Vaccines
Anti-viral drugs
(stop virus from
reproducing)

10. Influenza Pandemics!!! Occur when a new subtype of a virus arises
Humans have no or little immunity to it so everyone is at risk
Causes serious illnesses worldwide, sometimes in only 6-9 months

11. Influenza Pandemics!!!
Spanish influenza killed million people in 1918
Asian influenza killed 2 million people in 1957
Hong Kong influenza killed 1 million people in 1968

12. Bacteria

13. Bacteria Facts Prokaryotic, single-celled organisms
Can live in a variety of places
With oxygen
Without oxygen
Extreme heat
Extreme cold
Below and on\Earth’s surface
Existed for billions of years!

14. Bacteria Shapes Cocci are Spherical Bacilli and rod shaped
Spirilla and spirochetes are spiral shaped

15. How Bacteria Reproduce
Binary Fission
A form of asexual reproduction.
The genetic material duplicates and the cell divides into two identical cells.
Bacteria can grow and divide extremely rapidly!

16. How Bacteria Can Cause a Disease
Prevent the host tissue from working properly
Produce toxins which can destroy the host tissue

17. Bacteria is not always harmful!
Beneficial
Harmful
Decompose trash in landfills
Digest food
Produce vaccines
Preparation of foods
Yogurt
cheese
Bacteria can cause many illnesses
Strep-throat
Tuberculosis
Pertussis
Cholera
Anthrax
Leprosy
Meningitis

18. Treatment Antibiotics
Antibiotic resistance: Because we have overused antibiotics, mutant bacteria can survive antibiotic treatments and give rise to resist treatment.

19. BrainPop!

20. What diseases can you get from animals or insects?
Ticks = Lyme disease
Mosquitos = West Nile/ Malaria/ yellow fever
Dogs = Rabies/Ringworm/hookworm/roundworm/
Tapeworms…and many more
Reptiles = Salmonella
Cat = Toxoplasmosis/ tapeworms