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Questions # 8 - #16
#8
Bacteria vs Virus
Bacteria
Smallest in size
X
Unicellular organism
X
Contains DNA
X
Can reproduce on its own (via cell division)
X
Needs a host to reproduce
X
X
Prokaryotic
X
Cell wall
X
Has a protein coat
Killed by antibiotics
Virus
X
X
#9
A:
The virus attaches to the host cell
B:
The virus inserts its DNA into the host
cell
C:
The viral DNA instructs the host cell to
replicate new viral DNA
D:
The viral DNA tells the host cell to
make new viruses
E:
New viruses “explode” out of the cell
(the cell is no longer functional)
Antibiotics Kill Bacteria Cells
 How come our cells are
not destroyed?
“What is antibiotics? Chemistry Calendar, October: Health”
http://www.youtube.com/watch?v=lAg_xcHrAhE
Natural Selection
#10
How are humans causing antibiotic
resistance?
 “ Get Smart About Antibiotics”
http://www.youtube.com/watch?v=JiM
rcOc3HBM&feature=related
 When they don’t follow the
directions
 When they stop taking the
prescription when they “feel
better”
 When they share their
medicine with others
 When they pressure doctors
to give them a prescription
You never know if it will happen to
you…
“Teen may loose her hand to antibiotic-resistant,
flesh-eating, fish tank bacteria”
http://www.youtube.com/watch?v=9ZlrFrqLbo0&feature=related
#11
Transmission of Pathogens
1. DIRECT CONTACT:
Human  human contact (shaking hands, saliva or blood exchange)
2. INDIRECT CONTANT:
Human object  human contact (air, water, food, door knobs,
phones, computers)
3. VECTORS:
Non-human organism  human (ticks, mosquitoes, fleas, mice,
raccoons)
#12
Non Specific Immune Response
1st Line of Defense
“ Secure the Borders”
Natural barriers prevent
the entrance of a
pathogen.
Examples: skin, saliva,
tears and mucus.
#12
Non Specific Immune Response
2nd Line of Defense
“ Block the Breach”
Inflammation, fever and
white blood cells react to
the presence of any
pathogen.
White Blood Cell –
nd
2
Line
#12
Specific Immune Response
3rd Line of Defense
“Hunt Down Successful
Invaders”
T-cells and B-cells respond
to specific pathogens.
T- Cells: destroy infected
cells
B-Cells: create antibodies
Antibodies
#13
 Antibodies are produced by B-cells. They are Y-
shaped proteins that respond to an antigen (anything
the body recognizes as foreign).
 Each antibody binds to a specific antigen. Like a lock
and key.
 Antibodies attach to the antigen and signal the white
blood cells to destroy it.
 Antigens
Vaccination/Immunization
 Deliberate exposure to an infectious virus, without
developing symptoms of the disease. Antibodies will
be made due to this exposure.
#14
How Does A Vaccine Work?
 1. A piece of the dead or weakened
virus is used to make the vaccine.
 2. Inject the vaccine into your body
(1st exposure).
 3. Your immune system responds to
the vaccine by creating antibodies.
 4. When exposed to a live virus (2nd
exposure), the body will now
recognize it and begin producing
white blood cells to fight the
infection.
How does a vaccine work?
http://www.youtube.com/watch?v=kwVfcc1S7IU
http://www.youtube.com/watch?v=SduMbjW2V9A&feature=related
#15
A vaccine causes a Primary
Response. This is beneficial
because it will help the immune
system prepare for a response if
the person is exposed to the real
live antigen.
Secondary Response :
• the response will be more
rapid
• more antibodies will be
produced to prevent the
spread of the disease inside
the body
• the immune system’s
memory lasts longer
Why can’t we make a vaccine
for HIV?
 Viruses can mutate while replicating, this means
their DNA can change and have different
properties. Antibodies will not recognize the new
virus strains.
 It is too difficult for scientists to create a vaccine for
every new HIV strain.
Advantageous Mutation for
Humans
Beneficial microorganisms
 Helpful bacteria and fungi that are either added or
naturally occur in foods and other man made products.
E. Coli
Bifidobacterium
Lactobacillus
Penicillium
(fungi mold)
Saccharomyces
(fungi yeast)
#16
Human Digestion
 Microorganisms that live inside your intestines
are called “normal flora”. It helps your body
digest foods (sugar & fiber) and helps maintain
your immune system.
 E.coli lives produces vitamin K (helps prevent blood clotting).
 Lactobacillus can help prevent intestinal infections.
 Bifidobacterium relieves symptoms of Irritable Bowl
Syndrome (IBS).
#16
Food
 Certain bacteria, yeast and mold are used to
create unique flavors and textures of our food.
 Lactobacillaceae (bacteria) perform fermentation. It produces
lactic acid, which is used to turn milk into yogurt.
 Saccharomyces (yeast) perform fermentation. It produces alcohol
to make beer/wine and CO2 to help bread rise.
 Penicillium (mold) assist with the ripening and flavor of cheeses.
#16
Medicine
 Certain bacteria and fungi are used to create
prescribed medicines and other medical benefits.
 Penicillium (fungus) is used to make antibiotics.
 Probiotic pills are a mix of live microorganisms that can benefit
humans with immune heath and digestion (when taken in
adequate amounts).
 The human insulin gene has been inserted into E.Coli DNA. This
laboratory process allows us to mass produce human insulin for
diabetics.