Download Bacteria vs. Viruses

Bacteria vs. Viruses
I.
Bacteria and Viruses: Both can cause
diseases
Anthrax
A. Bacteria are living organisms (have DNA):
they can control functions and replicate on
their own
B. Viruses are not living organisms: they can
not control their own functions or replicate on
their own
1.
Made of a protein coat and nucleic acid
(RNA)
2. In order to replicate they must use a host
cell’s organelles and enzymes
C. Our Immune System
1. The Attackers (pathogens):
Bacteria or Viruses enter the body
through opening in skin or mucous
membranes
2.
The Defenders
a. Skin
b. Antibodies in blood recognize attackers 
white blood cells (lymphocytes) in blood
vessels, spleen, and bone marrow rush to
infection point
White Blood Cell
Red Blood Cell
3. The Kill!!!
a. White Blood cells “swallow” the
attackers and destroy them
D. Primary and Secondary Immune
Responses
1. The second time you are infected by a
pathogen (foreign invader), your immune
system works faster to fight it.
WHY?
2. Memory Cells: Protect against reinfection
by a specific pathogen
E.
Immunity and Vaccines
1. Immunity: resistant to a specific
pathogen
a.
Acquire immunity by being infected by a
pathogen and surviving the disease
OR
b. By a vaccine: contains pathogens or toxins
that have been modified so they can’t cause
the disease
2.
How do Vaccines work?
a.
b.
c.
Pathogens contain antigens (protein name
tags) that make immune system respond as if it
were harmful
Results in an increase in memory cells
Now body is ready to fight off pathogen in the
future