Viewing CellsViewing CellsViewing CellsViewing Cells

2.22.2

I. MicroscopesPut magnification to work…

1) Go out side and grab a leaf or blade of grass.2) Make a wet-mount slide3)Observe and draw a picture (label the cell wall, chloroplasts, vacoule and nucleus)

I. Microscopes

A. 1st Microscope1. Antonie van Leeuwenhoek2. Late 1500’s3. Noticed that 2 lenses from reading glasses made an image bigger.4. Magnified image 270X

I. MicroscopesB. Compound Microscope

1. Uses 2 lenses (simple only uses 1)

1 lens in the eyepieceX

1 objective lens----------------------------

Total Magnification

I. Microscopes

2. Eyepiece = 10X

Objective Lens = 40 ------------------------ Magnification = 400X

3. Compound microscopes can magnify up to 2000X

I. MicroscopesC. Electron Microscopes

1. Uses a beam of electrons instead of a light beam

a. Images are viewed in a vacuum so they cannot be alive.2. Can magnify up to 1,000,000X

I. Microscopes

3. Types of Electron Microscopes

a. Scanning Electron Microscope (SEM)

1)Makes a 3-D image of the cell’s surface.

I. Microscopes

b. Transmission Electron Microscope (TEM)

1)Makes a 2-D image of the structures inside the cell

I. Microscopesc. Scanning Tunneling Microscope (STM)

1) Shows the atoms on the surface of a cell

2) VERY POWERFULL!3) Uses computer generated graphics

II. Cell TheoryA. All organisms are made up of

1 or more cells1. Hooke first noticed cells1. Schleiden noticed this in plants2. Schwann noticed this in animal cells

B. The cell is the basic unit of organization in organisms

II. Cell Theory

C. All Cells come from pre-existing cells1. Virchow noticed that cells divide from other cells to reproduce

III. Prokaryote vs. Eukaryote

A. Prokaryote (“Pro” means NO)1. No nucleus2. No nucleus 3. No membrane-bound organelles (Not very organized)4. No more than 1 cell (Single-celled organisms)

III. Prokaryote vs. Eukaryote

B. Eukaryote1. Has a nucleus 2. Has membrane bound organelles3. More organized4. Single or multi-celled organisms

RECAP

-Who is the inventor of the microscope

-What kind of microscope uses 2 lenses to magnify

-How is an electron microscope different from a compound microscope

RECAP

-What are the 3 parts of the cell theory?

-Who named cells? Why did he name them cells?

-What is the difference between a prokaryote and a eukaryote?