The Diversity of LifeExtremophiles

Biology I

Jennifer Hood

What do the following places

have in common?

What do the following places

have in common?

What do the following places have in common?

What do the following places

have in common?

They are full of life!

(Only you can’t see it!)

Three Domains of Life

Now… a little bit of reading…

• Students will be handed copies of the April 1997 article in Scientific American titled “Extremophiles” by Michael T. Madigan and Barry L. Marrs

• Upon reading the article, students will be asked to focus on the questions on the following slides.

• Answers will be discussed but, at the moment, they are placed on the slides.

What is an extremophile?

• Organisms that thrive under conditions that, from a human point of view, are clearly extreme. Often, these organisms can not survive or reproduce unless in these punishing habitats.

T/F: Scientists have known about extremophiles for hundreds of years.

• False- some extremophiles have been known for only about forty years. More extreme ones have just recently been discovered.

• As technology improves, so does our ability to find these organisms and study them.

What is meant by the term ‘extremozymes’? What do they do? • Enzymes within extremophiles that remain

active when other normal enzymes would typically fail. (can tolerate a greater range of temperature, salinity, pressure, etc.)

• They speed up chemical reactions without being consumed themselves & can make major contributions to industry, biomedical research, etc.

T/F: Life is currently categorized into two domains- Bacteria and Eukarya.

• False- there is a third domain- Archaea.

• Mainly consists of extremophiles.

• Considered the most ancient domain.

• Organisms adapted to the conditions of early Earth (extreme temps, little oxygen, increased methane, etc.)

How are archaeans similar to bacteria? How are they different?

Similarities:

- No nucleus

- Similar in anatomy- simple

Differences:

- Shares genes with eukarya

- Have genes unique to archaea

These ‘extremists’ were first discovered in places like this hot spring

Grand Prismatic – Mid-Geyser Basin - Yellowstone National Park

Let’s get to know Earth’s most common extremophiles!

Your challenge:

From the illustrations on each slide, try to determine what type of extreme environment is occupied by a particular extreme organism.

Can you provide examples or organisms and/or locations?

thermophiles

hyperthermophiles

acidophiles

alkaliphiles

Xerophiles

barophiles

anaerobes

halophiles

radiodurans

toxicotolerant

psychrophiles

Discussion Question

• Why are extremophiles important?

How are humans affecting these extreme environments?

Reflection Questions• Why is life in extreme places important?

- Why is diversity of life important? - Could we survive without extremophiles? - How would we be affected if they were to

become extinct? - How can the study of extremophiles help us

understand life on other planets?- Who do you consider the extremophiles? Us or

them? (Remember- they were here first!) - Will human influence, over time, turn Earth

into an extreme environment? Why or why not?

• Will it help us find/understand life on other planets?

sources

• http://serc.carleton.edu/microbelife/extreme/index.html• Copyright• We encourage the reuse and dissemination of the material on this site for noncommercial purposes

(like education) as long as attribution is retained. To this end the material on this site is offered under a Creative Commons license Attribution-NonCommercial-ShareAlike 3.0.

• http://starcentral.mbl.edu/microscope/portal.php?pagetitle=assetfactsheet&imageid=12305– The content of this web site is freely available for educational and other non-commercial uses. Please

acknowledge the contributor and this web site. http://www.lpi.usra.edu/education/fieldtrips/2007/resources.shtml

aggregate of articles relating to extremophileshttp://www.worldbiomes.com/default.htm- free for educational purposeshttp://www.edupic.net/biomes.htm- free for educational purposesOur use policies

The Why Files is committed to offering broad access to the scientific enterprise. We encourage the use of our content — on the web or as hard copy — for non-profit, educational activities. Please credit, “Courtesy University of Wisconsin Board of Regents.” Our material must be used without alteration, and such use does not abrogate or diminish our copyright in any way. Our articles may not be sold, or used for commercial purposes or to endorse any product

NOAA site (government)CoolAntarctica.comUSGShttp://science.howstuffworks.com/cellular-microscopic-biology/extremophile.htm/printable