Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Chapter 2 – Measurement and Microscopy

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2 Different Cuts – or Sections ButtercupRoot Overview Cross Section

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3 Different Cuts – or Sections Longitudinal

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 4 Reading the Meniscus

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 6 Discovery of Microorganisms Antoine van Leeuwenhoek ( ) –first to observe and describe microorganisms

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 7 Figure 2.2

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 8 The Compound – multiple lens microscope

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10 Stereoscope

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 11 Microscope Resolution ability of a lens to separate or distinguish small objects that are close together wavelength of light used is major factor in resolution shorter wavelength  greater resolution At what point are the dots separate? Can they be resolved or separated from each other??

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 13 Resolving Power

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 14 Resolving Power Resolving power is the ability to make out detail Human Eye  0.1 mm Compound Microscope  0.2 um Electron Microscope  0.5 nm Limitations of Microscopes –Light waves – scattering causes distortion and unclear images –Maximum magnification is about 1500X

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 15 Electron Microscopy beams of electrons are used to produce images wavelength of electron beam is much shorter than light, resulting in much higher resolution

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 16 Transmission Electron Microscope electrons scatter when they pass through thin sections of a specimen transmitted electrons (those that do not scatter) are used to produce image denser regions in specimen, scatter more electrons and appear darker

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 17 TEM

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 18 Specimen Prep for transmission electron microscopy, specimens must be cut very thin specimens are chemically fixed and stained with electron dense material

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 19 TEMS ---> Ebola Virus

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 24 Silicon Atoms Researchers say being able to see how materials bond together at an atomic level could prove a significant benefit to the semiconductor industry, chemistry and in the development of new materials. For its latest findings, Researchers say being able to see how materials bond together at an atomic level could prove a significant benefit to the semiconductor industry, chemistry and in the development of new materials. For its latest findings, Looking straight down on a silicon crystal world record resolution of 0.6 angstrom about 1 millionth the diameter of a human hair.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 25 Scanning Electron Microscope 3D Images

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 26 The Scanning Electron Microscope uses electrons reflected from the surface of a specimen to create image produces a 3-dimensional image of specimen’s surface features

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 28 Common Dog Flea – Magnified 350X

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 29 Bristle on Common Earthworm – Magnified 350X

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 30 Trypanosome (parasite) next to a red blood cell.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 31 Diatoms

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 32 Fly head