1. The Cell History, Microscopes & Cell Theory

2. Cell Organism’s basic unit of structure and function Lowest level capable of activities of life Cells are: *Single-celled organisms *Subunits of many-celled organisms

3. What led to cell discovery? The invention of the MICROSCOPE!!!! Invention of the microscope made the study of Biology possible. Increased the life expectancy of people

4. Domain of Prokaryotes - Bacteria

5. Staph Bacteria

6. Bacteria that live in our Gut - If they died, we would starve in a month

7. Pseudomonas Bacteria – Issue: Burn Victims and Cystic Fibrosis

8. Streptococcus – Strep Throat

9. Anton van Leeuwenhoek The first living cells were seen by Anton van Leeuwenhoek. Anton van Leeuwenhoek was a Dutch cloth merchant who is given credit for making the first microscope. The first microscope he made was to inspect the quality of cloth. 1665

11. Robert Hooke The structure of the cell was first described by Robert Hooke (1700), an Irishman. Hooke thought that the squares of the cork that he viewed through the microscope looked like the rooms, or “cells”, that the monks lived in at the monasteries.

12. Hooke’s 1 st Microscope

13. Robert Hooke’s Cork Cells Drawing

14. Compound Light Microscope  view living organisms  Limited magnification  loss of resolution  Use a light source or mirrors to focus light on subject

15. Limiting Factor of Light Microscopes Resolution is limited due to the properties of visible light Ability to distinguish one thing from another Small bacteria are the smallest things you can “make out” with light microscopes Desire to see smaller things drove invention of electron microscopes

16. Compound Light Microscope OcularObjectiveTotal Magnification 10X4X40X 10X10X100X 10X40X400X

18. Light Microscope – Red Blood Cells

19. Normal and Sickle Red Blood Cell (SEM)

20. Electron Microscopes- (Expensive) Hospitals & Universities

21. Electron Microscopes Gave ability to observe more cellular detail Smaller things 3 Types of Electron Microscope ▫TEM (Transmission Electron) ▫SEM (Scanning Electron) ▫SPM (Scanning Probe) TEM image

22. Transmission Electron Microscopes TEM aims a beam of electrons through a specimen Denser areas appear darker Two dimensional images No live specimens with TEM or SEM

23. TEM Image of Elodea Cell

24. Scanning Electron Microscope (SEM) – 3D image Must slice objects very thin Sections laid out and stained with gold Creates magnified images by using electrons instead of light waves. A beam of high energy electrons is shot onto the specimen. Beam travels through a series of magnetic lenses designed to focus the electrons to a very fine spot.

25. SEM Procedures

26. (SEM) Shows very fine details of specimens – but surface only

27. SEM Image of Red Blood Cells Forming a Clot

28. Scanning Probe Microscope Three dimensional computer image of the surface of a specimen. Can view a specimen as small as one atom!!!

29. Cell Theory Schleiden and Schwann – 1839 1. All living things are made of cells 2. All cells come from pre-existing cells (life came from life) 3. The cell is the basic unit of structure and function of all organisms

30. Schwann studied Animals: Concluded that animal tissues are composed of cells.

31. Schleiden studied Plants: Carefully studied plant tissues and concluded that all plants are composed of cells.

32. Rudolf Virchow Rudolf Virchow studied disease and came up with … All cells come from pre-existing cells (life came from life)

33. Schleidan + Schwann + Virchow = CELL THEORY

34. Profound Discovery People had believed that mice and maggots spontaneously generated from piles of grain and rags Discovered by putting cheesecloth over rotting meat to prove flies causes maggots

35. Unicellular organism ▫Composed of one cell and all of life’s activities occur within that cell. Multicellular organism ▫Each cell carries on most of the major functions of life

36. We’re able to identify tiny details with modern microscopes

37. Plants Example: Elodea – water weed

38. Elodea cells (Plant cells)

39. Plant Cell Structure

40. Animal cell – Liver cell