1. Viruses

2. Viral structure Viruses are not cells.
Viruses are not considered living. (cannot reproduce by themselves- must use a HOST)
Basic structure:
Protein coat-CAPSULE or CAPSID
Nucleic acid core (RNA or DNA)
-ENVELOPE- outside protein coat in some viruses

3. HIV VIRUS

4. Virus Categories DNA viruses – stable, do not mutate rapidly
Single-stranded or double-stranded
Smallpox, Hepatitis B
RNA viruses – mutate rapidly, unstable
HIV, Rhinovirus

5. has a shape that matches a molecule in the plasma membrane
Viruses are host specific – a protein on the surface of the virus (GLYCOPROTEIN)
has a shape that matches a molecule in the plasma membrane
of its host, allowing the virus to lock onto the host cell.

6. LYTIC CYCLES Attachment Step 1 Step 3 Release Assembly
Step 2 Replication

7. Lytic Cycle (VIRULENT- or fast acting)
STEP 1-Virus attaches to host cell’s membrane and injects its nucleic acid into the host cell.
STEP 2- The viral nucleic acid takes over protein synthesis, creating new viruses. (can infect DNA or go straight to the ribosomes)
STEP 3- The host cell bursts, LYSES, releasing the newly formed viruses.

8. The Lysogenic Cycle

9. LYSOGENIC CYCLE- TEMPERATE VIRUS or slow acting
STEP 1-Virus attaches to host cell’s membrane and injects its nucleic acid into the host cell. STEP 2- Virus cuts into DNA and becomes part of the cell STEP 3- When cell reproduces so does the virus (DORMANCY)- STEP 4- LYTIC STAGE when stimulus is right

11. How are viruses spread?
AIR FOOD /WATER SEXUALLY TRANSMITTED SOIL

12. KINDS OF VIRUSES VIRUS Infected cells HERPES NERVE CELLS HIV
T – HELPER CELLS (WHITE BLOOD CELLS)
EBOLA
LINING OF THE BLOOD VESSELS (INTESTINES)
HUMANPAPILLOMAVIRUS (WARTS)
SKIN
MEASLES
DERMIS OF SKIN
WEST NILE
LYMPH NODES- NERVES
RABIES
BRAIN- NERVES
CHICKEN POX / SMALL POX
PNEUMONIA
LUNGS
INFLUENZA