The Sneeze: How germs are spread….

2. The Sneeze: How germs are spread…. http://www.youtube.com/watch?v=LzH-yat-mBI

3. How is disease spread in a class population? Liquid interactions Lab: • You will perform a lab in which they simulate the spread of disease through a population. • Then as a class we will perform an epidemiological study to locate the patient who first transmitted the disease or “patient 0”.

4. Liquid interactions Lab: In your lab notebooks draw this data table: Each group will collect one numbered test tube, which will represent their group. Write your group’s test tube number on the top of your lab sheet.

5. Liquid interactions Lab • Once your group has received their test tube, your task is to walk around the room and talk with another group of your choice for five minutes. • As you do this, using your pipette/droppers place two drops of the liquid from your test tube into the test tube of the group you are talking to. • Have this classmate give you two drops of liquid from their test tube.

6. Liquid interactions Lab: • Write the test tube number for the group who places drops into your test tube in the data table. • Repeat steps 1-3 with two other groups of your choice and record your information in the table below. • With each exchange of fluids, record the test tube number and time of interaction on your data table below for each interaction or “contact” you have with your classmates.

7. Liquid Interactions Lab

8. Center for Disease Control ALERT!!!!!! • Your town has just been mandated by the CDC (Center for Disease Control) to immediately be tested for a virus that is spreading rapidly!!! Please take the following steps and proceed with caution, as you do not know who is carrying the virus.

9. Lab Questions: • Based on your observations, discuss in your group the following: • What happened to your liquid? • Were you infected by the disease or did the disease miss you? Did every person in your group become infected? How do you know? • Who do you think was the initial carrier? Following your observation analysis: 4.In your groups draw a flow chart to determine the pattern of infection based on class data. Using your chart can your group: • Determine the initial carrier of the group • What data do you have to support your findings of the initial carrier. 5. If we did this experiment long enough, would everyone become infected, if so why, if not why not?

10. Reflection Questions:In your lab notebooks answer the following in a 5-7 sentence paragraph. • What conclusions based on your results can you draw about disease spread through a class population? • If we formed our own class CDC, what are some ways do you think we could prevent the spread of disease, and why? • Predict what would happen to our data if the virus was airborne? Food/Water borne? • If our class groups were continents, what are some ways that the virus could get from group to group or continent to continent?

11. Viruses Are they Alive??

12. Viruses – Are They Alive? What characteristics define living things? • Made of Cells • Respond to the environment • Need energy • Reproduce • Grow & Develop • Adapt Are viruses capable of these factors? Lets see…

13. So what makes a Virus a Virus? • Characteristics of Viruses: • Viruses ARE NOT made of Cells • Viruses must reproduce in living Cells (Can’t do this on their own) • Viruses can only be seen using an Electron Microscope • Viruses are made of a Nucleic Acid core and a Protein Coat

14. So are viruses living??? NO… • Viruses lack the basics functions that characterizes living things such as being composed of cells and having the ability to reproduce, thus they are NOT living!

15. So what makes up that tiny virus?Structure of viruses • Viruses are small packages of… • A core of Nucleic Acid – DNA or RNA, but not both • A protein coat, called a capsid, which surrounds and protects the nucleic acid of a virus.

16. Structure of Viruses • Some viruses have an Envelope on the outside of the capsid • It is made of phospholipids, proteins, and carbohydrates similar to the cell membrane • It may have “spikes” for recognition and attachment

17. The bacteria hunter: Bacteriophage • Only infects Bacteria…. (Weird Right?) • Structure: • Capsid – made of protein • Tail- used to help find a cell to infect • Nucleic Acid – Found in the Head

18. Viral Reproduction Lytic Cycle or Lysogenic Cycle

19. Viral Reproduction • Lytic Cycle • Causes immediate cell death once the cell is infected by the Virus T phage (type of bacteriophage) • Steps: • 1. Attachment • 2. Entry • 3. Viral Replication of Protein • 4. Proteins Assemble • 5. Cell Burst and Viruses are released

20. Viral Reproduction • Lysogenic Cycle • Does not cause immediate death of the cell • Steps: • 1. Attachment • 2. Entry • 3. Provirus Formed • 4. Cell divides with Provirus • 5. Virus DNA separates from host DNA • 6. Viral Replication • 7. Viral Assembly • 8. Cell Lysis

21. Viral Reproduction

22. Human Diseases • Viruses that cause human disease include: • Herpes, Chicken Pox, AIDS, Flu • Vaccinations can provide protection against some viruses • Makes your body produce antibodies • Small Pox was eliminated by vaccinations

23. HIV • HIV is a retrovirus – it can make DNA from RNA • Causes the disease AIDS • Have a capsid, an RNA core, reverse transcriptase, and an envelope

24. HIV • Parts of a Retrovirus • 1. Spikes – used to attach to a cell • 2. Capsid – made of Protein • 3. RNA – Nucleic Acid found in the capsid • 4. Reverse Transcriptase – enzyme needed for DNA to from RNA • 5. Envelope – make of phospholipids and proteins

25. Other Diseases • Viroids – pure, small pieces of RNA that cause disease in plants • Prion – pieces of proteins that cause diseases in animals • Mad Cow Disease – first seen in cows in England

26. VIRUSES