viruses -are nonliving pathogen -pathogen is anything that causes a disease. -why is it classified...

Viruses-are nonliving pathogen

-pathogen is anything that causes a disease.-Why is it classified as being nonliving?

1. not made up of cells2. has no organelles3. has no metabolism

Viruses use living cells as host:-uses the host cell to make

more viruses-can not function outside the host cell

Viruses do have:-their own copy of DNA or

RNA but LACKS its own cytoplasm or ribosomes so it can not do anything with its own the DNA.

Domain?-none because it is not

living

Kingdom?-once again none because

it is not living.

General structure of a virus:

1. DNA or RNA

2. Protein Coat/capsule surrounding the

genetic material. Capsules have specific shaped “receptor sites” which attach only on to a specific type of cell.

a. Tobacco plants b. Digestive system (#1 cause of diarrhea)

c. Respiratory system

d. Bacteria

Rabies…..nerve cells

Measles….skin cells

HIV……white blood cells

19–2 Viruses

Copyright Pearson Prentice Hall

Viruses cause:

-Common colds-Chicken pox-Measles-AIDS-Warts-Cold sores-Flu

Two types of Viral Infections:

1. Virulent Viruses:-causes illnesses

immediately-Ex/ flu and common cold

2. Temperate Virus

-does not cause disease immediately but exist inside host for weeks, months or even years.

-EX/ AIDS, Warts, Cold sores

Control of viruses within our bodies: Our own defense system

Our bodies 1st line of defense:- Skin

-pathogen must enter through an opening.

Our bodies 2nd line of defense:

-White blood cells (WBC’s)-WBC’s leave blood

stream and travel to the site of infection. -WBC’s engulf the

pathogen.

Recipe for pus?????

Our bodies 3rd line of defense:

-Antibodies

-Proteins made by WBC’s-Very specific/memory cells-For each foreign body that

enters your body, your WBC’s makes a specific antibody to destroy it.

-Remain in your body and can be used at anytime.

Chicken poxMeasles

Example: Get the measles or chicken pox once, you build up antibodies which will protect you for life from getting them again.

Vaccine:-injection of a

weakened form of a virus

-stimulates body to make

antibodies-stays in body

and destroys virus if it enters

Booster shot:-

revaccination to “boost”

your immunity.