1. What is the basic unit of all Organisms??
The Cell

2. Car Breaking down
Talk about how if one part of a car does not function the entire car does not function. Relate it to cells and organelles.

3. Hierarchy of living organisms:
Organ System -
Organ -
Tissues -
Cells –

4. Today: We are going to start talking about cells and the cell theory.
We will be filling out the notes I handed you the other day.
I will then hand you the first part of your study guide for your next test.
The second part will be cell organelles once we go over them.

5. The Basis of Life
Cells

6. Section 1: Introduction to the Cell

7. I. Discovery of Cells The invention of the lens
Robert Hooke (1665): observed a thin slice of cork (dead plant cells) with a microscope. He described what he observed as “little boxes” (cells).

8. I. Discovery of Cells
Anton van Leeuwenhoek (1675): was the first person to observe living cells.

9. II. Microscopes
Magnification: refers to the microscope’s power to increase an object’s apparent size
Resolution: refers to the microscope’s power to show detail clearly

11. 1. Light Microscope

12. Light Microscope
Elodea - Aquatic Plant
40X 400X

13. 2. Transmission Electron Microscope (TEM)

14. Transmission Electron Microscope (TEM)
Herpes Virus
Plant Root Cell

15. 3. Scanning Electron Microscope (SEM)

16. Scanning Electron Microscope (SEM)

17. Scanning Electron Microscope (SEM)
Mosquito Head
200X 2000X

18. Scanning Electron Microscope (SEM)
Fly Eye

19. Scanning Electron Microscope (SEM)
Inside of Stomach
Surface of Tongue
Neuron

20. Scanning Electron Microscope (SEM)
Pollen
Yeast
Red Blood Cell, Platelet, and White Blood Cell

21. TEM vs. SEM
Viruses leaving a cell

22. III. The Cell Theory Who developed the cell theory?
Matthias Schleiden (1838): concluded that all plants are composed of cells
Theodor Schwann (1839): concluded that all animals are composed of cells
Rudolph Virchow (1855): determined that cells come only from other cells

23. III. The Cell Theory What is the cell theory?
1. All living things are composed of one or more cells.
2. Cells are organisms’ basic units of structure and function.
3. Cells come only from existing cells.

24. IV. Cell Diversity
Size
Shape
Internal Organization

25. Cell Diversity- Size

26. Cell Diversity- Size Smallest Cells: Biggest Cells: Longest Cells:
6 inches long, 5 inches wide, 3 pounds
Ostrich Egg

27. Surface Area to Volume Ratio
SA = 6lw
V = lwh
SA = 6 mm2
V = 1 mm3
SA/V = 6:1
SA = 24 mm2
V = 8 mm3
SA/V = 3:1
SA = 96 mm2
V increases faster than SA
V = 64 mm3
SA/V = 1.5:1

28. Cell Diversity- Shape Cells differ widely in shape.
Most cells are roughly cuboidal or spherical.

29. V. Cell Diversity- Internal Organization
Nucleus: contains DNA which directs the activity of the cell
Organelle: a cell component that performs specific functions in the cell
Eukaryotes: cells that contain a nucleus and membrane-bound organelles
Prokaryotes: cells that lack nuclei and membrane-bound organelles

30. A. Eukaryotes vs. Prokaryotes
Eukaryotes (animals, plants, fungi, protists) and prokaryotes (bacteria) differ greatly in structure.

31. Prokaryotic Cell

33. Structural Organization of Eukaryotic and Prokaryotic Cells

34. Key Differences:

35. Eukaryotic cells are differentiated from prokaryotic cells because eukaryotic cells __________.
Are much smaller
Have permeable membranes
Have a higher rate of reproduction
Have nuclei D