1. Cell Structure and Function Chapter 7

2. Ch 7.1-Life is Cellular

3. How Did We Discover Cells?
Microscopes!
Invented in the late 1500s
Antoni van Leeuwenhoek (1600s)
Created some of the best early lenses
Submitted drawings of tiny living things he called “animalcules”

4. Who Called Them “Cells”?
Robert Hooke (1600s)
Observed cork
Empty boxes looked like monastery cells to him
Inspired the name for cells

5. The Cell Theory - Matthias Schleiden (1800s) - Theodor Schwann (1800s)
Stated that all plants are made of cells
- Theodor Schwann (1800s)
Stated that all animals are made of cells
- Rudolf Virchow (1800s)
Cells can only be produced by
existing cells

6. The Cell Theory 1) All living things are made up of cells
2) Cells are the basic units of structure and function in living things
3) New cells are produced from existing cells

7. Light Microscopes Allow light to pass through a specimen
Use lenses to magnify a specimen
Ocular lens is the lens you look
through
Objective lens is the lens above the
specimen
Compound Microscope
Dissecting Microscope

10. Cell Stains Most living cells are transparent
Staining cells can make them visible
Some stains work on entire cells, and some only on parts of a cell
- Some stains are fluorescent

11. Electron Microscopes Use electrons instead of light
Can show much greater detail than light microscopes
- Images are in black and white
Computers are used to add “false color”

12. Transmission Electron Microscopes
Pass electrons through a really thin specimen
Specimens are cut into ultra-thin flat slices

13. Scanning Electron Microscopes
Bounce electrons off the surface of a specimen
- Show the 3-D outline of a specimen

14. Types of Cells
Prokaryotes
Eukaryotes
- Do not enclose DNA in a nucleus - Always unicellular - Smaller, simpler cells
- Enclose DNA in a nucleus - Can be unicellular or multicellular - Larger, more complex cells