Dental English

Leeuwenhoek's World of Microbes

http://www.aichi-gakuin.ac.jp/~jeffreyb/dental/micro.html
rough machine translation ... [ Eng=>Jpn ]

        Anton van Leeuwenhoek (1632-1723) of Holland has been called the father of microbiology. Van Leeuwenhoek developed an interest in microscopes, which Zacharias Janssen had invented in 1590. As a hobby, he put together more than 247 simple ones--some of which were able to magnify objects 270 times. The son of a Dutch basket maker, Anton lived in Delft, Holland. Although he never attended a university and never had formal scientific training, this one man opened up a world that no one before him had seen.

        Van Leeuwenhoek set out to study as many things as possible under his home-made microscopes. With his shaving razor he would slice off very thin slices of cork, plants, or other specimens. One summer he heard reports that nearby Lake Berkel had an unusually greenish, cloudy look to it. So van Leeuwenhoek collected a water sample from the lake and placed it under one of his microscopes. He discovered a whole new world. There were little animals of various shapes and colors. Van Leeuwenhoek was the first scientist ever to give a detailed description of red blood cells (1675) and human spermatozoa (1677) or to see single-celled bacteria and protozoa. In 1683 he scraped some tartar off of his own teeth, looked at it under a microscope, and found living organisms.

        Van Leeuwenhoek made his discoveries known in letters to Europe's outstanding scientific societies. Over the course of fifty years, he wrote more than 300 such letters, many of which were published. At first people did not trust these reports. Then in 1673 the Royal Society of London sent an observer to Delft. His report confirming van Leeuwenhoek's claims caused such excitement that even the queen of England and the Czar Peter the Great of Russia (1698) stopped by to have a look for themselves.

        Here are some of the microbes that we can see with today's microscopes. Which ones can you identify?

a. b. c. d. e. f. g.

What other microbes can you think of? How are microbes classified? Are they all bad for human health?

References

[ Jpn=>Eng ] ... rough machine translations ... [ Eng=>Jpn ]

Hirsch, E.D. Jr. (Ed., 1993). Anton van Leeuwenhoek. What Your 5th Grader Needs to Know. New York: Delta Trade Books, pp. 384-385.

Unknown (1996). The World Almanac and Book of Facts. Funk and Wagnalls Corporation.

Waggoner, B. (1996). Anton van Leeuwenhoek. http://www.ucmp.berkeley.edu/history/leeuwenhoek.html .

Wales, J. et. al. (2005). Microorganism. http://en.wikipedia.org /wiki /Microorganism .


Discussion Questions

Are microbes different from single-celled animals? How?
Are there different kinds of microbes? Are they all bacteria?
What is a plasmid? What does it contain?
Some microbes are resistant to medicine. What is MRSA (methicillin-resistant
Staphylococcus aureus)? Can you name others?
Some microbes produce toxic substances. What makes E. coli O-157 different from other colon bacteria? What is Shigella dysenteriae? What is its role in making E. coli O-157 dangerous?
How are microbes used to make insulin?

Photos and Links

Links (other than references)
none

Photos--Used with Permission
none

Photos--Permission Pending
http://www.ucmp.berkeley.edu//history/leeuwen/leeuwenhoeksmall.jpg etc.
http://commtechlab.msu.edu/sites/dlc-me/zoo/microbes/media/penicil.gif etc.


Last updated March 2006
Copyright (C) 2001-2006 by Jeff Blair
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