The document discusses the discovery of cells and the development of cell theory. It explores key figures like Van Leeuwenhoek, Hooke, Brown, Schleiden, and Schwann and their contributions to early microscopy and the understanding that cells are the basic unit of life. It also summarizes different types of microscopes used to study cells, including optical, stereo, transmission electron, and scanning electron microscopes. Specimen preparation techniques for microscopy are outlined. Finally, it addresses why cells are small through the relationship between surface area and volume.

1. Into the world of cells…Development of cytology

2. Essential questionAre all living organisms made up of cells?

3. Discovery Of The CellAntonie van Leeuwenhoek1st person to see the cells

4. built his own microscope

5. looked in a drop of pond waterDiscovery Of The CellRobert Hookeconfirmed Leeuwenhoek’s observation

6. 1st to use the word “cell”

7. reminded him of the rooms in a monasteryDiscovery Of The CellRobert Browndescribed the nucleus

8. observed cytoplasmic streaming

9. conceptualized of “Brownian motion”Discovery Of The CellMatthias Schleidencontributed to the cell theory

10. stated plants are composed of cellsDiscovery Of The CellTheodor Schwanncontributed to the cell theory

11. discovered Schwann cells

12. cell is the basic unit of lifeDiscovery Of The CellRudolf Virchowfather of pathology

13. illnesses are due to malfunctioning of the cell

14. “Every cell comes from preexisting cell” Cell TheoryAll organisms are composed of cells.Cells are the basic unit of life.Cells come from preexisting cells.

15. Essential questionHow are cells studied?

16. MicroscopyIt is the technical field of using microscopes to view samples or objects

17. Microscopy BasicsMagnification is the process of enlarging an object only in appearance.

18. Microscopy BasicsResolutionis the ability to tell two points apart as separate points.

19. Microscopy BasicsResolution = __0.61 * λ__ NANA = numerical apertureλ = wavelength of light (760 nm)

20. Microscopy BasicsNumerical apertureNA = (n * sin α)n = refractive indexα = half the opening angle

21. Microscopy Basics

22. Microscopy BasicsResolving power is the microscope's ability to produce a clear image.

23. Microscopy BasicsDepth of Field (DOF) is the portion of a scene that appears sharp in the image.

24. Essential questionWhat are the different types of microscopes?

25. Types of MicroscopesOptical Microscope uses two lenses and visible light as the light source.

26. Types of MicroscopesStereo microscope creates a 3D image and used for dissection.

27. Types of MicroscopesElectron microscope uses a particle beam of electrons to illuminate a specimen. (2 types)

28. Types of MicroscopesTransmission (TEM) provides internal view of the specimen.Scanning (SEM) provides the external view of the specimen.

29. Essential questionHow are these specimens prepared for viewing?

30. Specimen Preparationscells are killed and heat-fixedto provide contrast: stained with colored dyes (optical); coated with electron-dense metals – Au, Pt, Pd and W(electron)

31. Other techniquesDifferential Interference – enhance density differencesPhase contrast – some regions appear brighter or darkerDark-field – light is scattered by the specimen