1. Chapter 3 Cell Structure

2. Section 1 Looking at Cells Most Cells are too small to see with the naked eye. Term coined by Robert Hooke after looking at cork under a microscope.(1665) Anton van Leeuwenhoek saw small animal in pond water as well. (1675) These were the first two descriptions of what we now call cells.

3. Measuring cell structures For convenience scientist use the nanometer and the micrometer when discussing cell and cell part size. µm= 10 -6 m (1/1,000,000m) nm= 10 -9 m (1/1,000,000,000m)

4. Cell size

5. Light Microscopes Project light through one or more lenses magnifying the image. Limited by the wavelength of light, anything smaller than that length can’t be imaged. Max magnification 2,000x

7. Light Microscope Focus Each lens has a focal length –Camera and eye adjust the lens –Microscope adjusts the distance When focusing the lend is moved up and down so be careful

8. E-Coli Light Micrograph E-Coli and Yeast E-Coli pink and yeast is purple

9. Electron Microscopes Shoot a beam of electrons rather than a beam of light. Much smaller wavelength thus one can image much smaller things. Much better resolution at higher magnifications than a light microscope. Max magnification about 200,000x Done in a vacuum so specimen is dead

11. Transmission Electron Microscopes Electrons shot through the specimen. 2 dimensional image that can be color enhanced.

12. Scanning Electron Microscopes Specimen covered in a thin layer of gold. Electrons bounced off the specimen and collected, creating a 3-D image. The image may also be color enhanced.

13. SIAM Scanning Interferometric Apertureless Microscope Resolution down to about 1nm –Visualizing down to the atomic level –Data storage Would allow us to put 30 movies on a DVD the size of a penny

14. Microscope Lab Work with your seat partner Microscopes are in the back Read through the lab before starting Put everything away including the slide when finished Remember that microscopes are EXPENSIVE!

15. Magic of Cells Video Cell types Cellular organization Cell functions Plant vs. Animal cells