1. Chapter 7 Section 1
Cells

2. The Cell Theory
. The Cell Theory states that all organisms are composed of similar units of organization called cells.

3. Beginning of the Cell Theory
In 1838, a German botanist named Matthias Schleiden concluded that all plants were made of cells
Schleiden is a cofounder of the cell theory
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4. Beginning of the Cell Theory
In 1839, a German zoologist named Theodore Schwann concluded that all animals were made of cells
Schwann also cofounded the cell theory
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5. . Schleiden and Schwann
Matthias Schleiden observed plants and Theodor Schwann observed animals. Both of them concluded separately that all organisms are made of cells.

6. Beginning of the Cell Theory
In 1855, a German medical doctor named Rudolph Virchow observed, under the microscope, cells dividing
He reasoned that all cells come from other pre-existing cells by cell division
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7. The Cell Theory
  1. All known living things are made up of cells.
2. The cell is the unit of structure & function of all living things.
3. All cells come from pre-existing cells by division. (No spontaneous generation ).

8. Microscopes
The Cell Theory would not exist if it wasn’t for the development of the microscope and the work of others.

9. Microscopes
Until scientists began using microscopes they believed diseases were caused by curses and supernatural spirits. They didn’t know about bacteria and other microscopic organisms.

10. . Robert Hooke
In Robert Hooke discovered cells in a piece of cork, and coined the word CELL.
What he saw looked like small boxes

11. First to View Cells Hooke is responsible for naming cells
Hooke called them “CELLS” because they looked like the small rooms that monks lived in called Cells
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13. Cells

14. Van Leeuwenhoek
Anton van Leeuwenhoek used his single lens microscopes and was the first person to observe bacteria and protozoa.

15. Leeuwenhoek’s microscope

16. Compound light microscope Electron Microscope SEM TEM STM
Types of Microscopes
Compound light microscope
Electron Microscope
SEM
TEM
STM

17. Compound Light Microscope
Can magnify object up to 1500X
This is an onion cell at 1000x magnification.

18. Electron Microscope
Uses electron beams to magnify structures up to times.
Structures inside of the cell can be seen with electron microscope.
SEM, TEM and STM

19. Compound Light Microscope
Ocular lens
. (eyepiece) times objective lens give total magnification
EX: 10 x 40

20. 1.Two Basic Cell Types
Prokaryotic Cells Mainly single celled organisms
Eukaryotic Cells Mainly multicellular organisms, although some are single celled (amoeba,algae, yeast)

21. 2. Prokaryotic Cell Prokaryotes have no membrane bound organelles.
Example –
bacteria cell

22. 3 and 4. Eukaryotic Cells
Eukaryotes – contain membrane bound organelles
Example – plants, animals, fungi, and protists

23. Organelles
5. An organelle is a small specialized structure inside of a cell.
An example of an organelle is the nucleus which controls cell functions.

24. Transmission Electron Microscope (TEM)
Can see inside a cell and the organelles
Scanning Electron Microscope
(SEM)
Scan the surface of cell to see its 3 D shape.
. Scanning Tunneling Microscope
(STM)
Can image atoms on the surface of a molecule.