1. VIRUSES Nature’s Robots

2. Viruses are so small they can only be seen with an electron microscope

3. General Characteristics of Viruses
Non-Living
Contain strand of genetic material: either DNA or RNA (1)
Encased in a Protein Coat: Capsid (2)
Have structures for attachment to a host cell (3)

5. Specific Characteristics of Viruses
Cannot make proteins
Require a vector; can’t move by themselves; require air, water, blood, body fluids, or other organisms
Smallest disease causing pathogen
Cannot replicate themselves, so they are called
obligate intracellular parasites
Are a mechanism for transferring DNA/RNA to cells: Good for genetic treatments | Bad can cause some cancers
Many shapes: spheres, hexagons, spirals, etc.

6. Viral Replication COLDS HPV: WARTS FLU GENITAL HERPES MEASLES SHINGLES
ASSEMBLY TRIGGERED
BY TRAUMA, OR
IMMUNE DECLINE
ATTACHMENT
RELEASE
VIRAL DNA GOES
DORMANT
INSERTION
ASSEMBLY
REPLICATION
COLDS
FLU
MEASLES
CHICKEN POX
HPV: WARTS
GENITAL HERPES
SHINGLES
COLD SORES

7. Flu Attack! How a virus invades your body

8. Defense Against Viral Infections
Since viruses are not living organisms, antibiotics are not effective. When a virus invades a cell it triggers a complex response from your immune system which, with time, defends the body from the invasion.
1st Line: Barrier
Skin, mucous membranes,
hair lining nose
2nd Line: Macrophages
Consume viruses, slow
3rd Line: T cells/B cells
Antibody production
Infection and response
results in: Natural
Active Immunity
Vaccine and response
results in: Artificial