1. The 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. 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 structure and function.(Schleiden & Schwann)( )
3. All cells come from preexisting cells. (Virchow)(1858)

8. Modern Cell Theory
Modern Cell Theory contains 4 statements, in addition to the original Cell Theory:
The cell contains hereditary information(DNA) which is passed on from cell to cell during cell division.
All cells are basically the same in chemical composition and metabolic activities.
All basic chemical & physiological functions are carried out inside the cells.(movement, digestion,etc)
Cell activity depends on the activities of sub-cellular structures within the cell(organelles, nucleus, plasma membrane)

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

10. A) Cell Membrane Analogy – City limits
Function: Regulates materials entering and exiting the cell.
Structure: Two layers of phospholipids, proteins
Analogy – City limits

11. B) Cytoplasm
Cytoplasm
Function: All cell contents that lie between the cell membrane and the nucleus. (organelles + cytosol)
a. Cytosol = liquid portion/non-organelles.
Structure: made up of fluid and organelles except for nucleus
Analogy – All air, water, life that are in Rocklin, except City Hall

12. C) Nucleus Function: “Control Center.” Regulates DNA & RNA actions.
Structure: membrane bound, contains DNA
Analogy – City Hall

13. D) DNA – Deoxyribonucleic acid
DNA (chromatin)
Function: information on how to make proteins.
Structure: Made up of nucleotides, locked in the nucleus
Analogy – The Laws or City Code

14. E) Endoplasmic Reticulum (ER)
Rough ER
Smooth ER
Function: Transportation route for proteins.
Rough ER: has ribosomes
Smooth ER: no ribosomes
Structure: tubes and channels
Analogy – Roads & Sidewalks

15. F) Ribosomes Function: Makes proteins.
Free Ribosomes
Function: Makes proteins.
Structure: small circular organelles
Analogy – Restaurants, Factories, Builders.

16. G) Vacuoles Function: Storage for water, nutrients or waste.
Vesicles
Function: Storage for water, nutrients or waste.
Structure: small membrane-bound organelle.
Analogy – Grocery stores, water tanks.

17. H) Lysosomes
Lysosomes
Function: packets of enzymes that break down materials in a cell.
Structure: Small membrane-bound organelles
Analogy – Recycling center

18. I) Mitochondria
Mitochondria
Function: Produce energy for the cell – site of cellular respiration. “The Powerhouse”
Structure: Double membrane-bound, kidney shaped.
Analogy – PG&E

19. J) Golgi Apparatus
Golgi Apparatus
Function: Packages, labels and ships proteins out of the cell.
Structure: Pancake-shaped layered organelle
Analogy – Post Office

20. K) Cytoskeleton Function: Provide support and structure for the cell.
Microfilaments
Microtubules
Function: Provide support and structure for the cell.
Structure: Tubules
Analogy – Wood, cement, steel beams

21. L) Chloroplasts (Plants only)
Function: site of photosynthesis (converting sun and CO2 into sugar).
Structure: Membrane bound organelles that contain chlorophyll
Analogy – Solar Panels

22. M) Cell Wall (Plant cells only)
Function: Provides support for the cell and the plant.
Structure: Made of cellulose
Analogy – ground, rock wall