Transcript Types of Microscopes

Types of Microscopes
Types of Microscopes
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Light Microscope: what we use in lab
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Uses light to magnify
Used to look at living cells
Magnify: up to 1500x
Electron Microscope: (1930-1940)
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Uses beams of electrons
Magnify: up to 500,000x
See inside of cells, look at structures
2 types
Scanning Electron Microscope:
(SEM)
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Scan surfaces of cells, look at 3D shape
http://www.mos.org/sln/sem/diatom.html
http://mse.iastate.edu/microscopy/whatsem.html
Transmission Electron Microscope
(TEM)
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Look at structures within the cell
http://en.wikipedia.org/wiki/Transmission_electron_microscope
New Technology
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New models & helpful techniques all the
time
Example: Scanning Tunneling Microscope
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Uses flow of electrons to create computer
images of atoms on the surface of a molecule
www.chem.utoronto.ca/staff/DHIRANI/index.htm
Cell Theory
The Cell Theory:
3 Main Ideas:
All organisms are composed of 1 or
more cells.
2. The cell is the basic unit of structure
& organization of organisms.
3. All cells come from preexisting cells.
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The Cell:
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With better microscopes, discovered that
cells contain small specialized
structures called organelles
Each organelle has a specific function
within a cell
Types of Cells:
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2 broad groups:
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Eukaryotes: contain membrane-bounded
organelles
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Most multi-cellular organisms & some unicellular
ones, like algae
Prokaryotes: do not
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Example: bacteria and other unicellular
organisms
What do they look like?
http://en.wikipedia.org/wiki/Eukaryotic
http://www.earthlife.net/prokaryotes/im
ages/bacteria.gif