1. Cells and Cell Theory

2. Leeuwenhoek • 1673-1723 Anton van Leeuwenhoek
* described live microorganisms
observed in teeth scrapings, rain water ,and peppercorn infusions.

3. The First Observations
• 1665 Robert Hooke
– reported that living things were
composed of little
boxes or cells.

4. Schleiden & Schwann Development of the CELLTHEORY
• Matthias Schleiden (1838) – using a microscope proposed that all plants are composed of cells
• Theodor Schwann (1839) – using a microscope proposed that all animals are composed of cells
• Together they stated:
– Cells are the elementary particle of all living organisms
– All cells are alive – independent to the organisms to which they belong

5. Virchow • 1858, Rudolf Virchow
said cells arise from preexisting cells.

6. * Named for the Monk prayer cells
Cell Theory
Cell Theory
1. All living things are composed of one or
more cells
2. Cells are the basic units of structure
and function in an organism
3. Cells come only from the reproduction
of preexisting cells
* Named for the Monk prayer cells

7. Cells Eukaryotic versus Prokaryotic Cells
• Prokaryotic - Cells lacking a nucleus.
• Eukrayotic - Cells containing a nucleus.
Organelles - Membrane-bound bodies found within eukaryotic cells.

8. Types of Cells Two Basic Types of Cells • Prokaryotes:
prounounced: pro-carry-oats
• Eukaryotes
– Proun: you-carry-oats

9. Eukaryotes Eukaryotes
Larger more complex cells that make up most familiar life forms:
plants, animals, fungi, algae
Surrounded by a cell
membrane made of
lipids

10. Prokaryotes Smaller No true nucleus – loose genetic material
Includes Archaea & Bacteria