Transcript Virus - Cloudfront.net

Write on section 3 everything you
know about the viruses.
•Are they alive?
•How are they?
•How do they reproduce?
•Why do they cause diseases?
Virus
Viruses are not alive
3. Viruses don’t have
organelles. They can’t
create energy on their own
because they don’t have
mitochondria or chloroplast.
Capsid
DNA or RNA
1. Viruses need a host cell to
live, because they need to
infect her to survive
2. In its structure, the virus
has:
• Nucleic Acids (DNA or
RNA)
•Protein Capsid
4. The viruses that infect bacteria are
called bacteriophage
Host cell – The cell that is
infected by the virus
5. Lytic cycle: a virus infects a cell, it
reproduces and it destroys the host
cell that it has just infected.
Virions are
released to
infect other
cells
What happens to the host cells
after being infected?
6. Lysogenic cycle:
•The cycle has an
extra phase that is
called PROPHAGE.
•The nucleic acid from
the virus gets
recombined with the
host DNA for a while.
•After that, it enters the
lytic cycle.
Virions are
released to
infect other
cells
HIV is a lysogenic virus
http://www.youtube.com/watch?v=F23ygNs
uOrM
Glycoproteins to be identified
AIDS (disease) vs HIV (virus)
7. AIDS – Acquired Immunodeficiency Syndrome
8. HIV – Human Immunodeficiency Virus
T LIMFOCITES
9. AIDS is developed when
the immune system cells are
destroyed, which leaves the
body vulnerable to any kind
of infection that doesn’t
affect the general population.
IT TRANSMITS HIV
IT DOESN’T TRANSMIT
HIV
BLOOD
SALIVA
BREAST MILK
THROUGH ANIMALS OR
FOOD
SEXUAL FLUIDS
AIR
10. The best way to prevent a viral disease is using a vaccine.
http://www.youtube.com/watch?v=jJwGNPRmyTI
11. Vaccine: A medicine that contains inactive or weak viruses.
What is the explanation about what
Edward Jenner did?
Do you think that it is ethical to do
this experiment in a young person?
How would you test a vaccine?
12. Viruses can be transmitted by:
Direct contact – Cold
Inhalation – Flu, chicken pox, cold
Bites – Rabies, West nile virus
Sexual contact – AIDS, hepatitis B
Contaminated blood
Contaminated needles
VIRUS DEL EBOLA
http://www.youtube.com/watch?v=ps_3DR
F3bq0
Bacteria
What do you know about bacteria? Talk
to your partner for 1 minute
Are they alive?
How do they look like?
How do they reproduce?
1. Bacteria are:
•Living things
•Unicellular
•Prokaryotic
No nucleus
:
Eukaryotic cell
2 bacteria kingdoms:
1.
Eubacteria – “true” bacteria. The most
extended organism on Earth
2. Archaebacteria “old bacteria”
-The oldest living things on Earth.
-They live in extreme conditions: very hot,
salty, acid locations
-Eukaryotic cells evolved from
Archaebacteria.
http://www.youtube.com/watch?v=
2IGKv8kiMqY
Bacteria can BE HARMFUL OR
BENEFICIAL TO HUMANS
Fact: In every cm2 from your skin you have an average
of 100,000 bacteria. A small spoon that has been in
contact with the floor contains more than
1,000,000,000 bacteria
Eubacteria
Streptococcus
Estafilococcus
Streptococcus
can cause
throat
infection
Lactobacillus
For example,
Lactobacillus helps
us make yoghurt.
Some bacteria are
harmful for humans,
while others are
beneficial for us.
Escherichia coli
helps us digest
food.
Nevertheless, if
we find it outside
from the intestine
tract, it can be
harmful.
What is bacteria?
http://www.youtube.com/watch?v=pcXdfofLoj0
The identification of bacteria
is based on their shape
1- Stick shape: bacillus
2- Sphere shape: coccus
3- Spiral shape: spirillum
Antibiotics
- They only kill bacteria  they
do not work to kill viruses
-How do they work?
-They prevent the formation of
the bacteria cell wall
-They break the cell
membrane
-They interfere in chemical
reactions
UNDERSTANDING BACTERIA
http://www.youtube.com/watch?v=UqZFiUWrZaE