Ch.19, section 2

Microbiology

Image from: http://evans.amedd.army.mil/lab/micro.htm

Part 2:

Viruses

How do viruses

differ from

bacteria?

• A nonliving particle that needs a host cell to survive

A. Definition

Images from: http://www.cosmosmagazine.com/node/1024; http://www.digitalhen.co.uk/news/health-14328300; http://www.ght.org.uk/news/category/non-progressors

Bacteriophage

Hepatitis

HIV

Made of 2 important things: 1. Contains

either DNA or RNA 2. surrounded by a

protein coat known as a CAPSID

Video clip 1 + 2

B. Structure

1. Lytic Cycle--virus IMMEDIATELY makes more viruses and destroys the host cell

C. Replication

2. Lysogenic cycle --These viruses can hide in host until signaled to replicate

C. Replication (cont)

Image from: http://wps.aw.com/bc_campbell_concepts_5/30/7911/2025347.cw/index.html

                                                                                             

                                                   

Lytic Cycle viruses

Lysogenic Cycle viruses

Video clip 3

Thus, Not all viruses replicate immediately.

D. Examples of Viruses

Images from: http://bacvirpara.blogspot.com/2011/07/varicella-zoster-virus-chicken-pox.html http://www.utmb.edu/virusimages/ http://www.doctortipster.com/6952-dutch-researcher-created-a-super-influenza-virus-with-the-potential-to-kill-millions.html;

Chicken pox Influenza

Rabies

1. Bacteriophage

D. Examples of Viruses (cont)

•a VIRUS that attacks bacteria •Have a protein "tail" attached that is used to infect the host bacteria.

Click on image

2. Tobacco Mosaic Virus

D. Examples of Viruses (cont)

= example of a plant virus

Image from: http://wps.aw.com/bc_campbell_concepts_5/30/7911/2025347.cw/index.html

3. Ebola

D. Examples of Viruses (cont)

= example of an animal virus

Image from: http://giantelectric.blogspot.com/2011/10/5-of-most-horrifying-things-ive-ever.html; http://www.betterworldbooks.com/the-hot-zone-id-0385479565.aspx

4. HIV (Human Immunodeficiency Virus)

D. Examples of Viruses (cont)

• This virus can lead to AIDS

• Is an example of a retrovirusContains RNA and reverse transcriptase

Image from: http://micro.magnet.fsu.edu/cells/viruses/hivvirus.html; http://scienceline.org/2007/07/scientists-moser-hiv-epidemiologist/

Video clip HIV and AIDS

5. Influenza Virus

D. Examples of Viruses (cont)

• RNA containing virus

• Mutates rapidly

Image from: http://www.utmb.edu/virusimages/; http://micro.magnet.fsu.edu/cells/viruses/influenzavirus.html; Video clip 4 + 5

Click on image

Magnification: approximately x70,000

E. Location of Infection

• Viral infections usually involve several parts of the body

• Examples:Cold and flu

Image from: http://lynnkerewchiropractic.com/blog/all-natural-remedies-for-the-flu/

F. Prevention

• Antibiotics CANNOT KILL viruses

• Instead, VACCINES are used to PREVENT viruses.

oVaccine= A dead or weakened version of a virus that helps to increase immunity in the host

Image from: http://www.sheknows.com/parenting/articles/851253/doctors-debate-the-benefits-of-vaccine-cocooning/

Video clip vaccines and eradicate smallpox

Measles Outbreaks Video ClipsPart 1: http://video.msnbc.msn.com/all-in-/52860666#52860666Part 2: http://video.msnbc.msn.com/all-in-/52860666#52860720

 Discovery Streaming “Understanding Viruses”Clips to show• Play part 1 time 2:30 to 17:20 (you will stop the playing after

the section on vaccines—so right when the section describing mutations comes on, hit stop)

• Then show clip 11, “The Death of Disease: Efforts to Eradicate Smallpox” (time 28:58)

• Then show clip 16, “HIV and AIDS” (time 38:43)• Finally show clip 18, “Using Viruses to Cure Genetic Diseases”

(time 45:00)  Understanding: Viruses. Discovery Channel School (1997). Retrieved June 4, 2008,

fromunitedstreaming: http://streaming.discoveryeducation.com/

Activities1. Video Clips

2. Vaccines Web Activity

Website for activity= http://www.pbs.org/wgbh/nova/bioterror/vaccines.html

3. Spread of Disease Activity

Image from: http://www.123rf.com/photo_4335978_pipette-with-drop-of-liquid-over-test-tubes-for-an-experiment-in-a-science-research-lab.html

Microbiology

The study of: microscopic organisms (bacteria) and particles (viruses)

MicrobiolgyPart 1:

Bacteria

How do viruses

differ from

bacteria?

A. Definition/FactsBacteria . . . Are prokaryotic cells Are unicellular Most numerous

organisms on Earth First forms of life

on Earth

Web visual found at http://learn.genetics.utah.edu/content/begin/cells/scale/

Click on image

What percent of

bacteria are

helpful?99%

A. Facts (cont)

Benefits of Prokaryotes:

+ food production+ digestion+ water purification+ environment—

decomposersoil spills

+ list is ENDLESS!!

—spoil foods —cause disease

A. Facts (cont)

A. Facts (cont)

Environmental Conditions:

a) Obligate aerobe= require oxygen to live

b) Obligate anaerobe= require a complete absence of oxygen to live

c) Facultative anaerobe= either/or (can survive with oxygen, but doesn’t need it)

B. Structure Fill in diagram

C. Reproduction1. MOST bacteria

reproduce by BINARY FISSION (see picture )

2. Conjugation: some bacteria exchange genetic info by forming a temporary bridge

3. Endospore: some bacteria form an endospore and go dormant when conditions are unfavorable

Image from: http://wps.aw.com/bc_campbell_concepts_5/30/7910/2025031.cw/index.html

C. Reproduction

Images from: http://www.3dscience.com/3D_Images/Biology/Bacterial/Bacterial_Types/Conjugation.php; http://bacteriakingdoms.com/conjugation-bacteria

Conjugation

C. Reproduction

Image from: http://wps.aw.com/bc_campbell_concepts_5/30/7923/2028311.cw/index.html

“To appreciate the explosive potential for population increase, consider a single bacterium that can reproduce by fission every 20 minutes under ideal conditions. There would be two bacteria after 20 minutes, four after 40 minutes, eight after 80 minutes, and so on. If this continued for a day and a half—a mere 36 hours—there would be bacteria enough to form a layer a foot deep over the entire Earth.” ~pg. 730 Campbell, N., Reece, J., Taylor, M., Simon, E. (2006). Biology:Concepts and Connections. Fifth edition. New York: Pearson Benjamin Cummings.

D. Shapes of Bacteria

Images from: http://biology.clc.uc.edu/courses/bio106/bacteria.htm

1.

= sphere

2.

= rod

3.

= spiral

Shapes Prefixes1.

= pair

2.

= chain

3.

= bunch

Streptococcus

Strep Throat

D. Shapes (cont)

D. Shapes (cont)

Escherichia coli - e.coli

Rod - Bacillus

Shape?

D. Shapes (cont)

Bacillus anthracis Death from anthrax is due to oxygen

depletion

Shape?

D. Shapes (cont)

CholeraIntestinal infection caused by ingestion of

contaminated food or water.

Shape?

Spiral - Spirillum

E. Location of Infection• Bacterial

infections are USUALLY localized at single point

• Examples:o strep throato urinary tract

infectionso most ear

infectionso some sinus

infectionsImage from: http://lynnkerewchiropractic.com/blog/all-natural-remedies-for-the-flu/

F. Treatment• Antibiotics CAN KILL bacteria• Antibiotic = Drugs that combat

bacteria by interfering with various cellular functions.

o Antibiotic resistant bacteria = ?

Alexander Fleming discovers penicillin in 1929

Images from: http://herbarium.usu.edu/fungi/funfacts/penicillin.htm; http://www.positivehealth.com/article/candida/superbugs-is-this-the-final-warning

Superbacteria: Evolution in Action

The misuse and overuse of antibiotics has lead to the evolution of resistant bacteria.

MRSA, TB, gonorrhea, malaria & typhoid fever have all evolved because of antibiotic misuse.

http://www.pbs.org/wgbh/evolution/educators/lessons/lesson6/act1.html

Fun Facts

• There are more bacterial cells in your body than there are human cells.

• Scientists estimate that bacteria produce nearly half the oxygen found in the atmosphere

• There are more microbes on your body than there are humans on the entire planet.

• An area of skin as small as 6.5 square cm (1 square inch) may be home to more than half a million microbes.

Bacte

ria

 United Streaming: “Understanding Bacteria”Clips to show• Play through the first four full segments—1-under the

microscope: anthrax 1:24, 2-understanding bacteria 3:55, 3-the good and bad sides of bacteria 11:06, and 4-Penicillin: From creation to resistance 5:15—then stop the video when “gold bug” comes up and discuss what was viewed with the class).

 Understanding: Bacteria. Discovery Channel School(2004). Retrieved June 4, 2008,

fromunitedstreaming: http://streaming.discoveryeducation.com/

 

Activities1. Video Clips

2. Mysteries of the Black Death

Video

Image from: http://www.rottentomatoes.com/m/secrets_of_the_dead_mystery_of_the_black_death/

3. Viruses vs Bacteria Venn

Diagram