This is a pptx file from PowerPoint 2007.

1. VIRUSES
Lect ure one

2. I. Part of a Virus
A. Nucleic Acids:
-DNA/RNA core
B. Protein
1. Protein Coat=capsid
a. capsid binds to
host
C. Lipids

3. II. Nonliving v. Living
A. Most consider a virus to be nonliving.
B. To reproduce, a virus must invade a host cell.
1. virus uses host cells “machinery”. Pay attention
to the following animation:
http://www.sumanasinc.com/webcontent/animations/
content/herpessimplex.html

4. III. Size & Shape
A. Microscopic compared to a bacteria cell.
B. Shape: (see viral color plate)
C. Examples:
1. Bacteriophage: virus that invades bacteria.
2. Tobacco Mosaic Virus: 1st
virus discovered.
a. viroid= a virus that infects plants.
3. Influenza: The flu
a. prion=a virus that infects animals.

5. IV. Viral Infections
A. Replication: occurs within
a host cell only.
1. Lytic Cycle:
invades---copies---destroys
2. Lysogenic Cycle:
Invades---copies---slowly
destroys

6. V. Treatment/Prevention
A. Vaccines: a
weakened or killed
virus to stimulate the
immune system.
B. Rest & Fluids
C. No antibiotics!!!
They lead to immunity.