1. Cell Theory

2. Some Random Cell Facts
The average human being is composed of around 100 Trillion individual cells!!!
It would take as many as 50 cells to cover the area of a dot on the letter “i”

3. Discovery of Cells
1665- English Scientist, Robert Hooke, discovered cells while looking at a thin slice of cork.
He described the cells as tiny boxes or a honeycomb
He thought that cells only existed in plants and fungi

4. Anton van Leuwenhoek
1673- Used a handmade microscope to observe pond scum & discovered single-celled organisms
He called them “animalcules”
He also observed blood cells from fish, birds, frogs, dogs, and humans
Therefore, it was known that cells are found in animals as well as plants

5. Development of Cell Theory
1838- German Botanist, Matthias Schleiden, concluded that all plant parts are made of cells
1839- German physiologist, Theodor Schwann, who was a close friend of Schleiden, stated that all animal tissues are composed of cells.

6. Development of Cell Theory
1858- Rudolf Virchow, German physician, after extensive study of cellular pathology, concluded that cells must arise from preexisting cells.

7. Cell Parts Cells – the basic unit of life
Organelles - small structures inside a cell with specific functions.

8. The Cell Theory Complete
The 3 Basic Components of the Cell Theory were now complete:
1. All living things are made of cells(Schleiden & Schwann)( )
2. The cell is the basic unit of life.(Schleiden & Schwann)( )
3. All cells come from preexisting cells. (Virchow)(1858)

9. Nucleus Function: Controls all the cell’s activities
Analogy – The teacher in the classroom

10. Cell Membrane Function: Controls what can enter and leave the cell
Analogy – A Door

11. Cytoplasm
Function: A jelly-like substance that fills the inside of the cell
Analogy – The water in a swimming pool

12. Ribosomes Function: Makes (builds) Proteins
Analogy – Construction workers

13. Vacuoles
Function: Stores materials (food, water, and waste) in the cell.
Analogy – Trashcans in the classroom

14. Mitochondria
Function: Provides energy for the cell
Analogy – Battery

15. Golgi Apparatus Function: Receives, packages, and ships out proteins
Analogy – UPS delivery

16. Lysosomes Function: Breaks down materials in the cell
Analogy – A blender

17. Endoplasmic Reticulum (ER)
Function: Allows materials to be transported throughout the cell
Analogy – Roadway system

18. Chloroplasts
Function: Takes in sunlight to make food (glucose) for the plant cell.
Analogy – Solar panel

19. Cell Wall
Function: Outermost layer of the plant cell. Protects the cell and gives it structure and extra support.
Analogy – Castle Wall