1. A Tour of the Cell
Chapter 7

2. Important People in Cell History
Notes Outline
Important People in Cell History
The Cell Theory
Major Types of Cells
How We Study Cells

3. Important People in Cell History

4. Galileo (1620’s)
Given credit as the first person to create a microscope (from a modified telescope)

5. Robert Hooke (1665) Observed cork cells (cork is dead plant matter)
Named the CELL  he said the cell looked like the “cells” in a monestary

6. Antony von Leeuwenhoek (1600’s)
Observed microscopic organisms with the first true light microscope
Observed the first bacterial cell (not seen again for over 200 years)
Observed red blood cells

7. What Leeuwenhoek saw
Spiral Bacteria
Red Blood Cells

8. Robert Brown (1833) Botanist
Observed that plant cells have a dark structure that stains in the middle
Named the structure he saw the NUCLEUS

9. Matthias Schleiden (1838) Botanist
Noticed that ALL plant tissues are composed of cells

10. Theodore Schwann (1839) Zoologist
Noticed that all animal tissues were composed of cells

11. Francesco Redi (1700’s)
Disproved SPONTANEOUS GENERATION (theory that all living things come from non-living matter)
Used meat & maggots in his experiment

12. Redi’s Experiment

13. Rudolf Virchow (1858)
Proposed that ALL cells come from pre-existing cells
Refuted spontaneous generation
Proposed BIOGENESIS (living things come from other living things)

14. Louis Pasteur (1862)
Further disproved spontaneous generation using meat broth experiment
Boiling a substance will kill any living matter (PASTEURIZATION)
Chicken Broth Experiment

15. Pasteur’s Experiment

16. The Cell Theory Notes Outline Important People in Cell History
Major Types of Cells
How We Study Cells

17. THE CELL THEORY
All living things are made of cells (Schwann & Schleiden).
All cells arise from pre-existing cells (Virchow, Redi, Pasteur).
Cells are the basic unit of structure and function of living things (Schwann & Schleiden).

18. Major Types of Cells Notes Outline Important People in Cell History
The Cell Theory
Major Types of Cells
How We Study Cells

19. Major Types of Cells Prokaryotes Eukaryotes 
No membrane-bound organelles (no nucleus)
Have DNA in nucleoid (floating in cytosol)
Unicellular
Bacteria (eubacteria and archaebacteria)
Pro = before
Karyon = nucleus
Eukaryotes 
Have membrane-bound organelles
Have DNA in nucleus
Unicellular and multicellular
Protista, fungi, plantae, and animalia
Eu = true

20. Key components to ALL cells
Cell (plasma) membrane
Cytosol (fluid inside membrane)/cytoplasm
Chromosomes (DNA)
Ribosomes (make proteins from DNA instructions)

21. How We Study Cells Notes Outline Important People in Cell History
The Cell Theory
Major Types of Cells
How We Study Cells

22. How We Study Cells
Light Microscope (LM)  uses a light source to reflect or refract a magnified image
Resolution  clarity of image
Magnification  amount image size is increased

23. Diatoms
Onion Root Tip

24. How We Study Cells
Electron Microscope (1950s)  focuses a beam of electrons through a specimen
Allows us to see organelles within a cell
Has a resolution about 200 X greater than LM

25. Mitochondria

26. How We Study Cells
Transmission Electron Microscope (TEM)  beam of electrons is passed through a thin section of a specimen
Electromagnets (acting as lenses) focus and magnify image
Stain specimen with heavy metals to see details

27. Cross section thru nerve cell – can see the layers of the myelin sheath surrounding axon

28. How We Study Cells
Scanning Electron Microscope (SEM)  electron beam scans the surface of a specimen coated with thin gold film
Electrons are excited as they bounce off surface and project an image onto a screen
Images are captured on film (like Polaroids)
Images appear to be 3D

29. Bacteria invading fungus
Nerve ending
Pollen
Various human
Blood cells
Bacteria invading fungus
Snow