1. Chapter 3 Section 1 Microscopes

2. Units of Measure  Metric system of measurement  International System of Measurement SI  Base Unit is the Meter (m)  Kilometer = 1,000 m (2/3 of a mile)  Centimeter =.01 m (1/2 diameter of penny)  Millimeter =.001 m (width of pencil tip)  Micrometer =.000001m (bacteria cell)  Nanometer =.000000001 m (water mol.)

3. Light Microscopes  Light passes through one or more lenses to produce an enlarged image of a specimen

4. Electron Microscopes  Forms an image of a specimen using a beam of electrons rather than light  3 Types  Transmission electron microscopes (TEM)  Scanning electron microscope (SEM)  Scanning tunneling microscope

5. Micrographs  The image produced by the microscope  Type of microscope  Magnification  Name of object  Light Microscope  320 magnification  Amoeba

6. Magnification & Resolution  Magnification  Makes the image appear larger than its actual size  Resolution  A measure of the clarity of an image  High magnification & good resolution are needed to view details of extremely small objects clearly.

7. Limitations of Microscopes  Light microscopes: lower magnification power but can view LIVING cells  Electron microscopes: higher magnification but cannot view living cells

8. Light Microscope  Ocular lens - closest to the eye  Objective lens - closest to the specimen  Both magnify  40x objective & 10x ocular = 400x magnification

9. Electron Microscopes  Can magnify 200,000x  Both electron beam and specimen must be placed in a vacuum chamber  Living cells cannot be viewed  3 Types  Scanning Electron Microscopes (SEM)  Transmission Electron Microscopes (TEM)  Scanning Tunneling microscopes

10. Scanning Electron Microscope  Specimen is coated with a thin layer of metal  3-D image of cell surfaces  Black & white image that can be artificially colored

11. Thin metal coating

12. SEM of Human Blood

13. Foot of a House Fly SEM x300

14. Transmission Electron Microscope  Cross section of specimen  Non living  Stain with metal ions  Electrons pass through specimen & form image  Image is in black & white (Can be enhanced with color)

15. Corona Virus (TEM)

16. Cytoplasm of Liver Cell (TEM)

17. Bacteriophages (TEM)

18. Golgi Apparatus (TEM)

19. Scanning Tunneling Microscope  3D image of the specimen’s surface  Can be used on living organisms

20. Scanning Tunneling Image