1. Table of Contents
Viruses
Bacteria
Viruses, Bacteria, and Your Health

2. Click the Video button to watch a movie about deadly viruses.
USAMRID
Click the Video button to watch a movie about deadly viruses.

3. Characteristics of Living Things
Similar Chemistry
Made of Cells
Grow
Use Energy
Respond
Reproduce

4. What Is a Virus? -Virus particles are very tiny. - Viruses
-A virus is a nonliving particle that enters and then reproduces inside a living cell.
-Virus particles are very tiny.

5. The Structure of Viruses
-All viruses have two basic parts:
1. protein coat--that protects the virus
2. inner core--made of DNA or RNA. (Some viruses are surrounded by an outer membrane envelope.)

6. The Shape of Viruses Viruses come in many shapes:
Many-sided (Icosahedron)
Example: Polio virus
Helical rods
Example: Tobacco mosaic virus
Robotlike
Example: Bacteriophage
Spherical or round
Example: HIV

7. Why are Viruses Nonliving
-Nonliving characteristics of viruses:
1. are not made of cells
2. do not use their own energy
3. do not grow or respond
4. can not make food, take in food or produce
wastes.
-Living characteristics of viruses:
1. contain DNA or RNA
2. contain proteins
3. can multiply---but NOT on their own

8. What cells do viruses enter?
-Viruses can enter the cells of ANY living organism.
-There are viruses that infect plants, animals, fungi, protists and even tiny bacteria cells!!!!
-They cause disease and are known as pathogens (any disease-causing agent).

9. Active and Hidden Viruses Activity
Click the Active Art button to open a browser window and access Active Art about active and hidden viruses.

10. How Viruses Multiply - Viruses
Active viruses enter cells immediately and begin to multiply, leading to the quick death of the invaded cells. The steps are:
Attach
Release
Inject
Assemble
Copy

11. How Viruses Multiply - Viruses
Hidden (Latent) viruses “hide” for a while inside host cells before becoming active.
Attach
Release
Inject
Assemble
Copy
Hide

12. How Active Viruses Multiply
Sequencing
As you read, make two flowcharts that show how active and hidden viruses multiply. Put the steps in the process in separate boxes in the flowchart, in the order in which they occur.
How Active Viruses Multiply
Attach: Virus attaches to the surface of a living cell.
Inject: Virus injects genetic material into cell.
Copy: Cell makes copies of viral proteins and genetic material.
Assemble: Viruses assemble.
Release: Cell bursts, releasing viruses.

13. How Hidden Viruses Multiply
Sequencing
As you read, make two flowcharts that show how active and hidden viruses multiply. Put the steps in the process in separate boxes in the flowchart, in the order in which they occur.
How Hidden Viruses Multiply
Attach: Virus attaches to cell.
Inject: Virus injects its genetic material.
Hide: Virus’s genetic material becomes part of cell’s genetic material.
Copy: Cell makes copies viral proteins and genetic material.
Assemble: Viruses are assembled.
Release: Cell bursts, releasing viruses.

14. Common Viral Diseases DNA Viruses RNA Viruses Measles Chicken pox
Small pox
Herpes
Parvovirus
Bacteriophages
Hepatitis B
RNA Viruses
Measles
Mumps
Rubella
Polio
AIDS
Colds
Flu
Ebola
Hepatitis A C and E
Viral pneumonia
Review Characteristics
Of Viruses

15. Virus Infection Review
Review the steps of an active virus infection by completing the following activity.
Virus Infection Review
Flipchart Activity

16. How Do You Catch a Virus? Contact with an infected person —coughing,
sneezing, shaking hands, etc. (colds and flu)
2. Contact with a contaminated object —sharing a drinking cup or utensils, etc. (colds and flu)
3. Insect and animal bites (West Nile and rabies)
4. Contaminated food and water (Rotavirus)
5. Sexual contact and exchange of body fluids (AIDS)

17. Fighting Viruses
-The Immune System is the body’s only defense against viruses.
-Three types of white blood cells and specific
antibodies are involved.
-There mission:
RECOGNIZE DESTROY REMEMBER
-Antibiotics and medicines do not work against viruses. Medications only treat symptoms. They can not cure a viral infection.

18. Vaccinations
-Vaccines—made from weakened or damaged virus particles that can no longer cause infection.
Trigger the body’s immune system to prevent
infections: not cure them.
2. First vaccine was developed by Dr. Edward Jenner in 1790 to prevent small pox.
3. Are now used to prevent many viral diseases.
Show video then notes

19. Gene Therapy
-Gene Therapy is a new technique in which scientists hope to cure people of genetic diseases using viruses.
*Replace a virus’s DNA with information needed to repair a person’s defective genes.
*The virus infects the cell with the good information.
*Good genes replace bad genes and the person is cured.
*Only animal studies have been done so far.
*May someday cure diseases like cystic fibrosis.

20. HIV and AIDS AIDS—acquired immune deficiency syndrome
First known case: Africa 1959.
HIV—human immunodeficiency virus
-The Virus that causes AIDS
-First seen in 1978: Identified and named in 1983
-Attacks the cells of the immune system so the
body cannot fight infections.
-It can take up to 10 yrs for an HIV infected
person to develop full-blown AIDS.
-RNA virus, so it mutates rapidly
-Work has begun on a vaccine: has not
been successful.

21. The Spread of Viruses
-World-wide the spread of viruses is increasing rapidly. -Why are previously rare viruses, like ebola, being reported in new countries?
1. Global travel and trade
World wide population growth.
Humans exploring remote areas.

22. End of Section: Viruses

23. The Bacterial Cell - Bacteria -Bacteria are prokaryotes.
*They have no nucleus.
*Their DNA floats free
in a gel-like substance
known as cytoplasm.
*Surrounded by a cell
membrane and cell wall.
*Some move using tail-
like structures known as
flagella. (one or many)
*Ribosomes also float in
the cytoplasm. They
make proteins.

24. Shapes of Bacteria Three basic shapes: 3. Spirilla—spiral-shaped
1. Bacilli—rod-shaped
2. Cocci—sphere-shaped

25. Obtaining Food and Energy
-Some bacteria are autotrophs (make their own food).
1. Photoautotrophs—use sunlight to make food
Example: Cyanobacteria (blue-green bacteria)--all
contain chlorophyll and are found in
lakes and ponds (usually as a cloudy
scum). Some have other pigments
that make them red, yellow or black.
(Red Sea named for red cyanobacteria).
2. Chemoautotrophs—use the energy from chemicals in their
environment to make their food. They live deep in
the mud or in extreme environments like hot springs.

26. Obtaining Food and Energy
-Other bacteria are heterotrophs (cannot make food).
*They feed on many different things.
*Some are important saprophytes—feeding on
decaying organisms.

27. Reproduction -Most bacteria reproduce by binary fission.
*Binary fission is a type of asexual reproduction
where one cell divides into two identical cells.
*Some bacteria can double their population every
20 minutes if conditions are just right. This means
that one cell can become one billion in just 10 hrs.

28. Sexual Reproduction
-Some bacteria use a simple form of sexual reproduction known as conjugation.
*Conjugation does not increase the number of bacteria cells. It just creates new combinations of genetic material to be passed on when new cells form through fission.

29. More on Bacteria - Bacteria Click the PHSchool.com button
for an activity about bacteria.

30. Population Explosion - Bacteria
Suppose a bacterium reproduces by binary fission every 20 minutes. The new cells survive and reproduce at the same rate. This graph shows how the bacterial population would grow from a single bacterium.

31. Population Explosion - Bacteria Reading Graphs:
What variable is being plotted on the horizontal axis? What is being plotted on the vertical axis?
Horizontal axis–time (minutes); vertical axis–number of bacterial cells.

32. Population Explosion - Bacteria Interpreting Data:
According to the graph, how many cells are there after 20 minutes? One hour? Two hours?
2 cells after 20 minutes;
8 cells after one hour;
64 cells after two hours.

33. Population Explosion - Bacteria Drawing Conclusions:
Describe the pattern you see in the way the bacterial population increases over two hours.
The number of cells doubles with each division.

34. Population Explosion - Bacteria Predicting:
Do you think the bacterial population will continue to grow at the same rate? Why or why not?
Not likely. The bacteria will continue to reproduce at this rate only as long as the conditions are favorable.

35. Role of Bacteria in Nature
-Bacteria can be helpful, harmful, or harmless.
Helpful Bacteria:
*Produce oxygen in the air
*Used in food production
(yogurt, cheese, pickles,
sauerkraut, sour cream)
*Decomposed dead organisms
*Turn nitrogen gas into usable
nitrogen products for plants
(nitrogen-fixing bacteria)
*Clean up oil spills
*Help digest food and make
vitamins
*Make medicines
Harmful Bacteria:
*Spoil food
*Cause disease
(Examples: strep throat, botulism,
diptheria, tetanus, whooping cough,
TB, Lyme disease, and anthrax)
Harmless Bacteria:
*Live among us totally
undetected. Do not
hurt or help.

36. Bacterial Diseases
Bacterial diseases are spread in the same manner as viral diseases:
Contact with an infected person (TB and strep throat)
Contact with a contaminated object (strep throat and tetanus)
Insect and animal bites (Lyme disease)
Contaminated food and water (botulism)
Sexual contact and exchange of body fluids (Hepatitus C)

37. Fighting Bacteria -Antibiotics can be used to kill bacteria.
*Antibiotic resistance —some bacteria can survive in
the presence of antibiotics. They multiply and the
disease continues. This makes some diseases
difficult to treat.
-Preventing infections is important
*Vaccines can be used for both bacterial and
viral infections.
*Hand washing
*Don’t share cups and utensils
*Cook and store foods properly
*Eat healthy, get rest, drink fluids, & exercise

38. Antibiotic Resistance
- Viruses, Bacteria, and Your Health
Antibiotic Resistance
Click the Video button to watch a movie about antibiotic resistance.

39. End of Section: Bacteria

40. Common Bacterial Diseases
- Viruses, Bacteria, and Your Health
Common Bacterial Diseases
Many bacterial diseases can be cured with antibiotics.

41. Common Viral Diseases - Viruses, Bacteria, and Your Health
Unlike with bacterial diseases, there are currently no medications that can cure viral infections.

42. Using Prior Knowledge - Viruses, Bacteria, and Your Health
Look at the section headings and visuals to see what this section is about. Then write what you already know about diseases caused by viruses and bacteria in a graphic organizer like the one below. As you read, write what you learn.
What You Know
You can catch a cold from somebody who has one.
Some diseases can be treated with medicines.
What You Learned
You can catch diseases through contact with an infected person, a contaminated object, an infected animal, or an environmental source.
Antibiotic resistance results when some bacteria are able to survive in the presence of an antibiotic.

43. Links on Infectious Diseases
- Viruses, Bacteria, and Your Health
Links on Infectious Diseases
Click the SciLinks button for links on infectious diseases.

44. End of Section: Viruses, Bacteria, and Your Health

45. Graphic Organizer
Nonliving
Can be
useful
Treated with
antibiotics

46. End of Section: Graphic Organizer