Do Now NB 144 top 8 minutes Expectations: –In seat at the bell, ready to go! –Notebook out! DO NOW: 1+ Paragraph –What did you learn about nutrition? –Are there any changes (big or small) that you plan on making?

Happy Monday Agenda! –Notes on Viruses –Short video + Bill Nye Video –Did your group present to me? –How many days left until EOGS??

Viruses Cornell Notes NB 145 & 147 Question | Details

What is a virus? The word VIRUS comes from the Latin word for “poison” or “slimy liquid”. A virus is a non-living particle that enters and then reproduces in a cell. It is: –Smaller than a cell –Not considered a living organism –Is virulent—it can cause disease

Where do viruses come from? Viruses may –Have de-evolved from higher life forms –Have started out at the same time as cells –Be escaped genetic material (or extra parts of a chromosome) That means that perhaps your body can make its own viruses!

Viruses are not cells They do not use their own energy to grow or respond to their surroundings They cannot make food, take in food or produce waste They can multiply—but only when they are inside another living cell Viruses come in many shapes and sizes

Properties of a virus Viruses consist of DNA or RNA but never both

Diagram of a virus NB 146 Viruses can be brick, cylindrical or oval in shape or they may have more complicated structures almost like robots Scientists can use the shape of a virus to identify it

(virus shapes, continued..) RabiesEbola Influenza Early Italian scientists Thought this illness was caused by the INFLUENCE of the stars And planets.. Hepatitis Polio Rhinovirus (common cold) Rotavirus

Virus size Viruses vary in size They are smaller than cells They cannot be seen with our microscopes. They are between 20 nm and 200 nm (1 nm = 1/1,000,000,000 th of a meter)

Virus names Viruses are named for –The disease they cause (polio virus) –The organisms they infect (tobacco mosaic virus) –The place where they were found (West Nile virus) –The scientist who discovered the virus (Epstein-Barr virus—causes mononucleosis)

Rabies

Influenza

Smallpox Edward Jenner

Polio Dr. Jonas Salk

Parts of a Virus Viruses have two basic parts –A protein coat that protects the virus –An inner core of genetic material Viruses connect to cells with a “lock and key” method

How do viruses (most) attack cells and make us sick?? Let’s use the T4 bacteriophage as an example: T4 bacteriophage is a virus that looks a lot like an alien landing pod------> With its six legs, the bacteriophage attaches to the surface of the much larger bacteria Escherichia coli (E. coli). Once attached, the bacteriophage injects DNA into the bacterium. The DNA instructs the bacterium to produce masses of new viruses. GShQ

So what happens to the bacterium? So many new “baby” viruses are produced that the E. coli BURSTS!! This process of bursting is called LYSIS.

Active and Hidden viruses Both inject genetic materials into the host. Both burst open the cell after they multiple Both kill the host. Active viruses multiply immediately Hidden viruses hide and multiply later. Hidden viruses can stay inactive for years. Each time the cell divides, the virus’ genetic material is copied along with the host’s genetic material

Are any virus’ good? Viruses can cause disease. Viruses can be helpful. –Cow pox virus helps make people immune to small pox