1. CHAPTER 7 CELL STRUCTURE & FUNCTION PGS. 168 - 199 CELL STRUCTURE & FUNCTION

2. ANTON VAN LEEUWNENHOEK One of the first person’s to use a microscope. Looked at pond water and saw small organisms.

3. ROBERT HOOKE Looked at plant tissues in 1665. He specifically looked at cork. Looked like tiny chambers he called “cells”

4. 4 Microscopy Today: Compound Light Microscope Light passed through specimen Focused by glass lenses Image formed on human retina Max magnification about 1000X Resolves objects separated by 0.2  m, 500X better than human eye

5. 5 Compound Light Microscope eye amoeba, light micrograph light rays ocular lens objective lens specimen condenser lens light source a. Compound light microscope 85 µ m © Robert Brons/Biological Photo Service Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

6. 6 Microscopy Today: Transmission Electron Microscope Abbreviated T.E.M. Electrons passed through specimen Focused by magnetic lenses Image formed on fluorescent screen Similar to TV screen Image is then photographed Max magnification 1000,000sX Resolves objects separated by 0.00002  m, 100,000X better than human eye

7. 7 Transmission Electron Microscope electron source electron beam b. Transmission electron microscope specimen 200 nm pseudopod segment, transmission electron micrograph observation screen or photographic plate electromagnetic objective lens electromagnetic condenser lens electromagnetic projector lens © M. Schliwa/Visuals Unlimited Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

8. 8 Microscopy Today: Scanning Electron Microscope Abbreviated S.E.M. Specimen sprayed with thin coat of metal Electron beam scanned across surface of specimen Metal emits secondary electrons Emitted electrons focused by magnetic lenses Image formed on fluorescent screen Similar to TV screen Image is then photographed

9. 9 Scanning Electron Microscope amoeba, scanning electron micrograph electron gun electron beam electromagnetic condenser lenses scanning coil final condenser lens secondary electrons specimen electron detector c. Scanning electron microscope 500m TV viewing screen © Kessel/Shih/Peter Arnold, Inc. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. µ

10. 10 Microscopy and Amoeba proteus eye amoeba, light micrographamoeba, scanning electron micrograph light rays ocular lens objective lens specimen condenser lens light source a. Compound light microscope electron gun electron beam scanning coil specimen c. Scanning electron microscope electron source electron beam b.Transmission electron microscope specimen 85 µ m 200 nm 500 µ m pseudopod segment, transmission electron micrograph electromagnetic condenserl enses final Condenser lens secondary electrons observation screen or photographic plate electromagnetic objective lens electromagnetic condenser lens electromagnetic projector lens electron detector TV Viewing screen a: © Robert Brons/Biological Photo Service; b: © M. Schliwa/Visuals Unlimited; c: © Kessel/Shih/Peter Arnold, Inc. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.