1. Chapter 4: Cells 4.1 Intro to Cells; History; Microscopes Pg. 51-53
Objective: I can explain how the cell theory came to be and identify which microscopes can best view which object by factors of 10.

2. Cell Theory 3 ideas All organisms made of 1 or more cells
Cells arise from preexisting cells
Cell = smallest, most basic living thing
Things to note:
Where did first cell come from?
Are viruses alive?
This is a theory, which means…
Proven with evidence, can be disproven

3. Cell Theory History Anton van Leeuwenhoek Made “1st” microscope
Robert Hooke
Named/discovered cell
Matthias Schleiden
All plants made of cells
Theodor Schwann
All animals made of cells
Robert Virchow
Cells come from other cells

4. Visualizing cells: They’re tiny
Magnification: enlarging image size versus real size  wide range of sizes!

6. Visualizing cells: They’re tiny
Units  100 meters = 1 m
103 (1000) meters = 1 kilometer (km)
10-2 meters = 1 centimeter (cm)
10-3 meters = 1 millimeter (mm)
103
102
101
100
10-1
10-2
10-3

7. Visualizing cells: They’re tiny
Units  100 meters = 1 m
10-6 meters = 1 micrometer (µm) = micron
10-9 meters = 1 nanometer (nm)
10-10 meters = 1 Angstrom (Å)
10-6
10-9
102
101
100
10-1
10-2
10-3
10-10

8. Magnification: enlarge image
These two are related, but separate concepts
Resolution: minimium distance two points can be apart and still see as two different points
10-6
10-9
102
101
100
10-1
10-2
10-3
10-10

9. Resolution
Minimum distance 2 points can be apart and still see as 2 different points
Higher resolution = can distinguish at smaller distances
Based on wavelength of light
Increase resolution with shorter wavelength

10. Microscopes Light microscope: uses light/lenses
What about magnification & resolution?
Microscopes
Light microscope: uses light/lenses
Compound microscope: multiple lenses
Electron microscope: uses electrons
Scanning (SEM): scan outside
Transmission (TEM): transmit inside
Color?

23. Other Microscopic Images