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

Capsid DNA or RNA Viruses are not alive 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 3. Viruses don’t have organelles. They can’t create energy on their own because they don’t have mitochondria or chloroplast.

4. The viruses that infect bacteria are called bacteriophage

5. Lytic cycle: a virus infects a cell, it reproduces and it destroys the host cell that it has just infected. Host cell – The cell that is infected by the virus What happens to the host cells after being infected? Virions are released to infect other cells

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 Glycoproteins to be identified Nucleic Acid (RNA) CAPSID VIRAL ENVELOPE uOrM

AIDS (disease) vs HIV (virus) 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. 7. AIDS – Acquired Immunodeficiency Syndrome 8. HIV – Human Immunodeficiency Virus T LIMFOCITES

IT TRANSMITS HIVIT DOESN’T TRANSMIT HIV BLOODSALIVA BREAST MILKTHROUGH ANIMALS OR FOOD SEXUAL FLUIDSAIR

10. The best way to prevent a viral disease is using a vaccine 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 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

: Prokaryotic cell 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.

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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 Bacteria can BE HARMFUL OR BENEFICIAL TO HUMANS

Streptococcus can cause throat infection Estafilococcus Eubacteria Streptococcus

Lactobacillus Some bacteria are harmful for humans, while others are beneficial for us. For example, Lactobacillus helps us make yoghurt.

Escherichia coli helps us digest food. Nevertheless, if we find it outside from the intestine tract, it can be harmful.

What is bacteria?

1- Stick shape: bacillus 2- Sphere shape: coccus 3- Spiral shape: spirillum The identification of bacteria is based on their shape

- 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 Antibiotics

UNDERSTANDING BACTERIA