Shadowwalker
Wednesday, 12 December 2012
Tuesday, 13 November 2012
1) Electron microscopes provide more detail into a cell than, for example, a light microscope. many cell organelles and chemical processes can be studied in more detail using the electron microscope.
2) The electron microscope has been particularly useful in studying bacteria, because _____.?
2) The electron microscope has been particularly useful in studying bacteria, because _____.?
A) electrons can penetrate tough bacterial cell walls
B) bacteria are so small
C) bacteria move so quickly they are hard to photograph
D) with few organelles present, bacteria are distinguished by differences in individual macromolecules
E) their organelles are small and tightly packed together
Random - There are two types of electron Microscopes....
Scanning electron microscopes (SEM)work like shining a strong light on the specimen and then detecting the light comming off.
(in this case a beam of electrons)
Because the wavelength is so small, (much smaller than visible light) you can see extremely small things
SEMs can magnify 0bjects up to 100,000 times. a regular light microscope can only magnify up to about 1000 times.
The second type of EM is the Transmission Electron Microscope. It acts more like a regular microscope by passing electrons THROUGH the specimen. naturally the sample must be very thin.
TEMs can magnify objects up to 15,000,000 times (some even better) In some cases for solids, you can even see rows of atoms. (the resolution is ~1.5 angstroms or about 0.2 atoms wide)
B) bacteria are so small
C) bacteria move so quickly they are hard to photograph
D) with few organelles present, bacteria are distinguished by differences in individual macromolecules
E) their organelles are small and tightly packed together
Random - There are two types of electron Microscopes....
Scanning electron microscopes (SEM)work like shining a strong light on the specimen and then detecting the light comming off.
(in this case a beam of electrons)
Because the wavelength is so small, (much smaller than visible light) you can see extremely small things
SEMs can magnify 0bjects up to 100,000 times. a regular light microscope can only magnify up to about 1000 times.
The second type of EM is the Transmission Electron Microscope. It acts more like a regular microscope by passing electrons THROUGH the specimen. naturally the sample must be very thin.
TEMs can magnify objects up to 15,000,000 times (some even better) In some cases for solids, you can even see rows of atoms. (the resolution is ~1.5 angstroms or about 0.2 atoms wide)
Monday, 5 November 2012
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