1. VIRUSES
B 4.C
Compare the structures of viruses to cells, describe viral reproduction, and describe the role of diseases such as human immunodeficiency virus (HIV) and influenza

2. Videos – Viral invasion of the body
Part 1
Part 2

3. What is a Virus? Much smaller than cells
A NON-LIVING infectious agent made up of a core of DNA or RNA surrounded by a protein coat.
Viruses need host cells to replicate the viral DNA. They enter a living host cell and hijack it to produce more viruses
Viruses eventually kill their host cells
(Reproduce)

4. Parts of a Virus Capsid: Protein coat Genetic core: DNA or RNA
IS NOT LIVING!!!!!!!
IS NOT A CELL!!!!!!!
DOES NOT have organelles!!!!

5. Protein Coat (part that hold the DNA)
Legs (anchor the virus to the cell)

6. Viruses cannot be destroyed by antibiotics!!!!
A cure for viruses?
No said “cure” for a virus, only preventions
Vaccine —weakened or deadened form of a virus
Viruses cannot be destroyed by antibiotics!!!!
Antibiotics are for bacteria – not viruses!

7. We Classify Viruses by:
Shape (what they look like)
Host (the type of cell they infect)
Function (how they infect cells)
Genetic Core (DNA or RNA)

8. Viral Shapes Shape: Binal Helical Enveloped Examples: Tobacco Mosaic
RNA
Capsid
proteins
Head
Tail sheath
DNA
Tail fiber
RNA
Capsid
Surface
proteins
Membrane
envelope
Examples:
Tobacco Mosaic
Virus
Influenza Virus
T4 Bacteriophage

9. CAPSID
WEST NILE VIRUS
HERPES
SARS

10. HEPATITIS B
BIRD FLU

11. One Type of Viral Replication
Virus attaches to host cell
Virus injects DNA or RNA into cell
Viral DNA or RNA is replicated or reverse-transcribed
Transcription and Translation takes place to make capsid
Cell assembles viruses
Cell is lysed, new viruses are released and infect other cells

12. Cell Virus

13. Viruses that affect humans
Influenza (the flu)
HIV
Chicken pox; Shingles
Herpes
Common colds
Epstein Barr
HPV
Rabies
Measles
Mumps
Rubella
Polio
West Nile
Hepatitis A, B, C
Ebola
Small pox

14. Human Immunodeficiency Virus
HIV causes AIDS
HIV attacks Helper T-Cells, which are vital to our immune system
Since HIV decreases the immune system, a person is more prone to secondary infections than a normal person
Mutates too quickly to make a vaccine

15. InFLUenza Symptoms: High fever, sore throat, fatigue, aches, coughs
Mutates regularly. That is why we have vaccines yearly
Can be air borne - When some one coughs or sneezes, you can contract the virus by breathing it in.
What shape are these viruses?

16. SARS Severe acute respiratory syndrome
Airborne- can be transmitted when an infected person coughs or sneezes.

17. Common Colds Upper respiratory infections (nose, throat, lungs)
Usually clear up in 2 weeks without complications
More than 200 known viruses can cause colds

18. Small pox Virtually eradicated! Small pox vaccine was made from cowpox
Only found in 2 labs on Earth: Russia and US
Small pox vaccine was made from cowpox
Symptoms:
High fever, aches, rashes

19. Human Papilloma Virus (HPV)
Affects both men and women
Sexually transmitted
Can cause cervical cancer
Gardasil – vaccine that may prevent cervical cancer

20. Herpesvirus Chicken Pox
Fever
Incubation of 14 days
Red itchy rash
Vaccination available
Other herpesviruses include Herpes (cold sores and genital herpes)

21. Measles High fever Sore throat, cough, sneezing Rash
Dangerous for pregnant women
You received a vaccine for MMR (measles, mumps, rubella)

22. Polio
Symptoms: Fever, headache, muscle weakness, difficulty swallowing
Hundreds of thousands affected until vaccination became available
Franklin D. Roosevelt, President from 1932 to 1945

23. Ebola 1977 Ebola Zaire (picture) Named after the Ebola River in Zaire
High hemorrhagic fever
High death rate

26. Viruses vs. Cells