1. Introduction to the Cell and Cell Theory

2. Important events in the discovery of the cell and the development of the cell theory…..

3. 1665 – Robert Hooke Named them "cells”. Observed cells in cork.
Cork Cells

4. 1673- Anton van Leeuwenhoek
Created a powerful microscope

5. Robert Brown
-noticed that pollen grains in water jiggled around
-discovered the nucleus
Nucleus
Human Cheek Cell

6. A botanist who concluded that all plants are made of cells.
Matthias Schleiden
A botanist who concluded that all plants are made of cells.
Typical Plant Cell

7. 1839 - Theodor Schwann A zoologist who concluded that all animals
are made of cells.
Nerve Cells

8. 1855 - Rudolph Virchow A physician who did
research on cancer cells and concluded
“Omnis cellula e cellula”.
“All cells are from other
pre-existing cells.”

9. The 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 existing cells.

10. both in size, shape, and internal organization.
Cells are Diverse…
both in size, shape, and internal organization.

11. Why Are Cells So Small?
Transport- Cell volume to surface area demands a small size.
Control- Nucleus to cytoplasm consideration.

12. Note: 1.0 mm = one millionth of a meter
How small can a cell be?
Mycoplasmas - bacteria that are 0.1 to 1.0 mm (1/10 the size of regular bacteria).
Note: 1.0 mm = one millionth of a meter

13. All cells have…… Plasma (cell) Membrane Nucleus (eukaryotes only)
Cytoplasm (area inside the cell)
Organelles (structures with
specialized functions)

14. Cell Types
Prokaryotes- simple cells that do not have internal membranes.
Example = bacteria
Eukaryotes- more complex cells that do have internal, membrane-bound structures.
Examples = plants and animals

15. Key Differences: Eukaryotes Prokaryotes
Have a nucleus and other membrane bounded structures.
DNA is organized into chromosomes.
Prokaryotes
Lack a nucleus and other membrane bounded structures.
DNA is not organized into chromosomes.

16. Examples
Prokaryotic
Eukaryotic
Nucleus

17. Eukaryotic
Prokaryotic