5--Viruses

1. Obligate parasites
2. Can crystallize, not cell-based.
3. Mutate because it lacks good repair mechanism.
4. Core of nucleic acids, either RNA or DNA, surrounded by protein capsid.

Viruses when outside of host.

Difficult, usually cultured on living tissue or medium.

Coat of protein around virus.

Tight coil, such as rabies virus.

Polyhedron shape, such as herpes virus.

Both helix and polyhedron shapes, such as phage virus.

Infected cell reproduces viruses, often copying surrounding genetic material. Result in resorted viruses.

When genetic material is copied from surrounding areas in the reproduction of a virus. Affects influenza evolution, resulting in resorted viruses.

Contains RNA fragments from Indiana pig farm in 1987, and older ones from Asia.
Includes pig flu strain, avian flu strain, human strain.

Lytic and Lysogenic

Short term illnesses as colds and influenza.

Initial Infection: viruses attach to host at receptor site, injects genome.
Replication: genome codes for reproduction, directing cell to make proteins, replicate viral DNA or RNA, and assemble to produce viruses.
Outbreak (Lysis): Enzymes dissolve host's cell membrane. Viruses are released to attack other cells.

Where viruses attach to cells, on cell membrane. Many anti-viral medications aimed at binding to receptor sites to block viral attachment.

genetic material

Genetic diseases that are chronic or life-long.

Initial Infection: Viron attaches to host and injects genome, which attaches to the host's DNA.
Replication: Window phase. Few symptoms, but copies of provirus are made during mitosis of infected cell.
Lytic Cycle: Triggering event activates lytic cycle.
Outbreak: Enzymes dissolve host's cell membrane, viruses are released to attack other cells.

Carries reverse transcriptase enzyme to convert viral RNA into DNA.

Viral DNA attached directly to host's DNA, life-long part of host's genetic material.

Depression, illness such as cold, other factors, weaken body, bringing on outbreak.

HIV, Herpes, Hepatitis B, Chicken Pox

Herpes simplex virus (HSV-2) or HSV-1
may infect lips and mouth
window phase: 2-20 days before outbreak with uclers
NO cure

Human papilomavirus (HPV)
Window phase: 3 weeks to 3 months
May lead to cervical cancer
IS a HPV vaccine for prevention

Stimulation of pre-oncogene into cancer coding gene. May occur in liver by Hepatitis B virus.

Genetic transformation of normal cells into tumor cells, as herpes virus associated with cervical cancer.