1. Viruses
Pages 54-59
Example problems:
Page 59, #1,2,6

2. Viruses

3. What are viruses?
Definition

4. Are viruses alive?
Characteristics of viruses

5. Which Human Diseases Are Caused By Viruses?
DNA viruses
Respiratory disease
Smallpox
Chicken pox
Mononucleosis
Cold sores
RNA viruses
AIDS
Influenza (flu)
Common cold
Polio
Measles
Rabies
Which Human Diseases Are Caused By Viruses?
Viruses cause diseases in the many organisms that they infect. This slide lists some of the more well-known infectious diseases of humans caused by DNA and RNA viruses. Viruses also cause significant problems in animals and plants.
Some viruses, referred to as “tumor viruses,” also can cause cancer. The cancer-causing abilities of some tumor viruses have been demonstrated only in animals. However, there is growing evidence that certain viruses cause specific types of human cancers. For example, some types of papillomavirus, a DNA virus, have been identified as a cause of cervical cancer. HTLV-1, a retrovirus, causes a type of adult leukemia.
References:
Campbell, N.E., & Reece, J.B. (2002). Biology (6th ed.). San Francisco: Benjamin Cummings.
Flint, S.J., Enquist, L.W., Krug, R.M., Racaniello, V.R., and Skalka, A.M. (2000). Principles of Virology: Molecular Biology, Pathogenesis, and Control. ASM Press.

6. Virus structures A virus consists of these main parts:
Genome (DNA/RNA)
Capsid (protein)
Envelope (lipid)
genome
capsid

7. Viral structure Genome Genetic material of the virus Capsid (core)
A protein shell surrounding the genome.
Envelope
A layer of lipid (fats) that separate the virus from the outside environment

8. Viral Structure

9. Viral Structure
Envelope

10. Bacteriophage Structure
Infect bacteria
More complex compared to other types of viruses
Head =
Tail =

11. Infectious Cycle
Lytic cycle

12. Infectious cycle
Lysogenic cycle

13. Infectious cycles