1. The Virus

2. What is a Virus?
A small NON-LIVING particle that invades and reproduces itself inside a living cell.

3. Are Viruses Living?? Cellular Organization Contain similar chemicals
Use energy to grow or respond
Growth and development
Response to surroundings
Reproduction (multiply) X

4. Do viruses multiply the same way as other organisms?No
Uses a host:
A living thing that provides the source of energy for a virus.
A mutation in the H1N1 influenza A virus,
termed the SR polymorphism,
enhanced replication of the virus in humans.
(Image courtesy of NIGMS)
Acts like a parasite:
Organisms that live on or in a host
and causes harm to the host

5. Which of the Six Kingdoms do Viruses Infect?
Archaebacteria
Protists
Plants
Yes
Yes
Yes
Eubacteria
Fungi
Animals
Yes
Yes
Yes
Yes – They infect all living Organisms
Each kingdom has its own set of viruses

6. Viruses also invade specific areas of an organism!!
Cold virus invades the nose and mouth
Hepatitis virus attacks the liver
Tobacco Virus – the Tobacco Leaf

7. Some Pictures of Viruses
Tomato mosaic Virus
Bubo virginianus
Ebola virus
This is a bacteria

8. Viruses you might have heard of:
Influenza causes common flu
Polio causes muscle weakness and paralysis
Herpes causes Mononucleosis (mono) and chicken pox
HIV causes AIDS
Hepatitis cause liver malfunction
Measles causes a body rash and flu-like symptoms
Ebola
Tomato mosaic

9. Viruses (4 min)

10. Size and Shape of Viruses
Viruses come in different shapes and sizes.
Their shape determines what they will infect.
How big are they Click

12. Structure of Viruses Genetic Material Outer Protein Coat
Protect the virus
Acts as the key to lock onto a living cell
The protein in the outer coat must match the proteins in the cells membrane

13. How Viruses Multiply
Outer Protein coat locks onto specific host cell surface.
Virus’s genetic material is injected in host cell and takes over cell’s function.
Active virus – immediately
Hidden virus – delayed
Cell Produces Virus’ protein and the genetic material over and over and then assembles new viruses.
Cell becomes full and bursts.

16. How are Viruses used to help us?
Gene Therapy
In Gene Therapy viruses are used because they can attach to a host cell and inject good DNA into an infected cell.
Scientists use viruses to change the genetic makeup of these cells.

17. Understanding Viruses Part 1 and 2 (54 min)