Transcript DNA viruses: herpes simplex virus

Bubonic plague is one of the deadliest pandemics in human history. It killed 3060% of Europe’s population between 1348-1350 and took 150 years for Europe's
population to recover.
Since AIDS was first recognized in 1981, it has led to the deaths of more than
25 million people, making it one of the most destructive diseases in recorded
history.
Dairy product produced by fermentation of milk. People have been making
and eating yogurt for atleast 5,500 years!
Global outbreak that began in Mexico, approximately 600,000 people infected
world-wide.
Humulin was the first medication produced using modern genetic engineering
techniques in which actual human DNA is inserted into a host cell. The host
cells are then allowed to grow and reproduce normally, and due to the inserted
human DNA, they produce a synthetic version of human insulin. Humulin can be
used as a treatment for diabetes.
•Infectious Disease: any change, other than
injury, that disrupts the homeostasis of the
body. There are different agents of disease,
the most common being: bacteria, protists,
fungi, and some animals.
•Homeostasis- the process by which organisms
keep conditions relatively constant internally,
even when external conditions do not remain
constant.
• Physical contact
•Infected food or water
•Vectors- animals that carry pathogens from
person to person
• Fights infection 2 different ways:
1. Nonspecific Defenses
•First Line of Defense: skin and mucus!
•Second Line of Defense: inflammation!
Inflammation is when your white blood
cells go to your infected tissue and causes
it to become red and swollen. This can also
raise your temperature and cause a fever.
2. Specific Defenses
•The immune system reacts and attacks a
specific pathogen. The defenses are called
an immune response. The trigger is called
an antigen.
•There are two types of cells that recognize
specific threats: B cells and T cells.
•Characteristics of Living Things
1. Made up of cells
2. Reproduce (sexual or asexual)
3. Have DNA
4. Grow and Develop
5. Obtain materials and energy
6. Respond to their environment
7. Change over time
Viruses and Living Cells
Characteristic
Made up of cells
Reproduction
Have DNA
Grow and Development
Obtain and Use Energy
Respond to the Environment
Change Over Time
Virus
No
Cell
Yes
Must have a host Sexual or asexual
Yes
Yes
No
Yes
No
Yes
No
Yes
Yes
Yes
• A non-living parasite
• Must use living cells to reproduce. All
viruses enter and take over host cells to
produce more viruses.
 Nucleic Acid- DNA or RNA in the inner core
containing information to make copies of the
virus.
 Capsid- Outer protein coat that surrounds the
DNA or RNA. This makes them very specific to
what they infect. The ‘spikes’ sticking out fit like
a puzzle piece to trick cells into letting them in.
 The virus attaches to the host cell , enters it and
takes over. Only then can the virus replicate.
http://www.tvdsb.on.ca/westmin/science/sbi3a1/Bacvirus/Virusrep.htm
 A typical lytic cycle takes about 30 minutes and
produces about 200 new viruses.
 The virus enters the cell, copies itself, and causes
the cell to burst.
 The virus enters the cell and instead of
immediately taking over the host’s genetic
material, the viral DNA is combined into the
host cell’s chromosome.
 This type of infection can stay as a permanent
fixture in the hosts DNA reappearing as a viral
outbreak at different times throughout the
hosts life (like herpes-caused by the herpes
simplex I Virus).
 A virus recognizes and attaches to a host cell
when one of its proteins interlocks with a
molecular shape that is the receptor site on the
host cell’s plasma membrane.
 The recognition and attachment process is like
two pieces of a jigsaw puzzle fitting together.
 Rhinoviruses cause the common cold
 HPV (Human papillomavirus) can cause cervical
cancer in women
 Herpes simplex viruses cause mouth and/or
genital sores, lesions, and ulcers.
 Influenza viruses cause the flu
 HIV (Human Immunodeficiency Virus) causes
AIDS and weakens the immune system
 Alive
 Capable of reproducing on its own
 Capable of growing and developing during its
‘life’ cycle
 Antibiotics DO NOT work on viruses.
 Most human viral infections can be fought off
by the immune system—boost the immune
system with lots of water and rest.
 Vaccines are preventative!!! (Vaccines will not cure you
if you are already sick. They stimulate the immune system to create an
immune response that recognize a certain virus. These antibodies
patrol your body and if they recognize that virus…they call in
reinforcements and your immune system goes into battle!)
DNA viruses: herpes simplex virus (HSV)
Varicella zoster virus (VZV)
•Chickenpox
•Shingles- Re-activation of
latent infection
 Ebola hemorrhagic fever
(Ebola HF) is a severe,
often-fatal disease in
humans and nonhuman
primates
 Appeared sporadically
since its initial
recognition in 1976.
 Transmission arthropod
bites.
 No known treatment.
 The first virus to be identified was a plant
virus, called tobacco mosaic virus
 400 identified viruses that infect plants with
1000 different diseases
 Cause stunted growth and crop losses
• Prokaryotic (no nucleus)
• Unicellular
• Autotrophs or heterotrophs
• Aerobic (uses oxygen) or anaerobic
• Can be motile using pili or flagella
Bacteria come in a wide range of
shapes, sizes and colors!
Bacillus
Spirulina
Bordetella
Clostridium
Staphylococcus Streptococcus
Escherichia
Salmonella
1. Binary Fission- bacteria doubles their size and
DNA, then divide in half to produce two
identical daughter cells.
2. Conjugation- a hollow bridge forms between
two bacteria and they exchange DNA.
3. Spore Formation- some bacteria grow spores
when conditions are unfavorable. An
endospore is formed when bacteria produce
a thick internal wall that closes off all the DNA
and small portion of the cytoplasm. Spores
can remain dormant for long periods of time.
Allows bacteria to survive extreme heat,
dryness, or lack of nutrients that might
otherwise kill them.
Binary
Fission
1 bacterium
can become
1/2 million in
6-7 hours
Conjugation
Draw
these!
• Digestion- Escherichia coli is in our gut and aides in digestion.
Other bacteria in the digestive tract provide us with different
vitamins we need.
• Food- Lactobacillus bulgaricus is found in cheese and yogurt!
• Decomposers- help break down dead and decaying stuff.
• Nitrogen-fixation- turns the nitrogen in the air into a usable form
that plants need.
• Industry- can digest petroleum, which aides in oil spills.
• Water treatment- removes waste and poisons from the water.
• Staphylococcus aureus-food poisoning
when toxins are ingested
• Streptococcus pyogenes-causes strep
throat—red spots on your throat are red
blood cells the bacteria have destroyed
• Clostridium botulinum-produces toxins that
cause paralysis for 4-6 months (botox
injections are made of these toxins!!!)
• Pasteurization is used to
remove bacteria from food
• Antiseptics can kill bacteria on
tissues
• Antibiotics are used to kill
bacteria that have entered the
body (penicillin, amoxicillin,
tetracycline, ciproflaxin)
• Vaccines can prevent bacterial
infections by stimulating the
immune system
• Also- cook and refrigerate your
food properly, and wash hands
NOT classified because THEY
ARE NOT ALIVE
Classified into the Kingdom
Eubacteria or Archeabacteria
Non-living parasite
Living
Cannot reproduce on their
own (uses a host cell)
Can reproduce sexually or
asexually
Contain DNA or RNA inside Contain circular DNA inside
a protective coating (capsid) a cell membrane and cell
wall
Always pathogenic
Can be helpful or
pathogenic
Bacteria vs. Virus
Characteristic
Number of Cells
Does it reproduce on its
own?
Type of Nucleic Acid
Form of Nutrition
Is it living?
Does it cause disease?
Can it be helpful?
Can antibiotics kill it?
Can it move on its own?
What does it look like?
Bacteria
Virus
 Use the following words:
o
o
o
o
o
o
o
o
Alive
Float/Don’t move on own
Blows up cells
Eat sugar and O2
Not alive
Swim
Cells
Built by host cell
o
o
o
o
o
Don’t need to eat
Reproduce
Can’t reproduce on
own
DNA/RNA
Makes waste that
kills cells