1. 4-1 Notes: History of Cell Biology

2. Cells Smallest unit that can perform life processes Random Facts
Average human is composed of 100 trillion cells
It would take 50 cells to cover the dot of an “i” on your paper

3. Who discovered cells?

4. 1. Hook, 1665 Discovered cells while looking at cork (plant cells)
Described them as tiny boxes or rooms
“cell” means little rooms in Latin
Thought cells only existed in plants and fungi

5. 2. Leuwenhoek, 1673 Observed pond scum & found single-celled organisms
One of the first to look at living cells
He called them “animalcules”

6. Year Gap???
Between the Hooke/Leuwenhoek discoveries and the mid 19th century, very little cell advancements were made.
This is probably due to the widely accepted, traditional belief in Spontaneous Generation.
Examples:
-Mice from dirty clothes/corn husks
-Maggots from rotting meat

7. 19th Century Advancement
Much doubt existed around Spontaneous Generation
Conclusively disproved by Louis Pasteur

8. 3. Schleiden, 1838 German botanist
Stated that all plants are made up of cells

9. 4. Schwann, 1839 German Physiologist
Stated that all animals are made up of cells

10. 5. Virchow, 1858 German Physician Studied cellular pathology
Concluded that cells must come from existing cells

11. Cell Theory
1. All living things are made up of one or more cells (Schleiden & Schwann )

12. Cell Theory
2. Cells are the basic units of structure and function in living things.
(Schleiden & Schwann )

13. Cell Theory
3. All cells are produced by the division of existing cells. Virchow (1858)

14. Cell Types and Common Parts

15. What differences do you notice?

16. Type of Cells Type of Cells
Prokaryotic: lack membrane-bound organelles
Unicellular
Simple
Capsule, cell wall, cell membrane
Nucleoid (DNA)
Cytoplasm
Ribosomes
Cilia, flagella
Oldest living cells
Ex: bacteria

17. Prokaryotic

18. Type of Cells Type of Cells
Eukaryotic: contain a membrane-bound nucleus and organelles
Unicellular and multicellular
More complex
a. Ex: Plant and animal cells

19. Prokaryote
Eukaryote

20. All Cells have the following in Common
1. Plasma Membrane
Acts as a barrier to the outside world
Semi-permeable: Allows only certain materials to leave and enter

21. All Cells have the following in Common
2. Cytoplasm
Gel like substance
Fills space between nucleus and organelles
Most reactions happen here
3. DNA
Control Center
Regulates cells function

22. Thinking Maps
Prokaryotic Coloring and Reading