1. Viruses

2. Vocab Pathogen: anything that causes disease.
Epidemic: large outbreak of a disease.
Pandemic: disease outbreak that covers large geographical areas.

3. Bacteriophages Viruses that infect bacteria
pierce the host cell membrane, inject DNA/RNA.
capsid
DNA
tail sheath
tail fiber

5. Lytic infection Destroys the host cell. 1. Attach 2. Insert DNA
3. Cell’s machinery is used to replicate viral structures.
4. Structures assembled
5. Release of new virus

7. Lysogenic infection Does no immediate harm Stages: 1. Attach
2. Insert DNA
3. Viral DNA integrates with host DNA
4. Viral DNA is replicated with host DNA
5. May switch to lytic cycle.

9. Prions Retrovirus Infectious, mis-folded protein.
Causes normal proteins to change shape.
Agent that causes Mad Cow disease.
Virus that has RNA
RNA is transcribed into DNA in the cell.
Viral DNA combines with host DNA.
Ex: HIV

10. Vaccines Made from dead or damaged virus particles.
Stimulate an immune response without causing disease.