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) -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 MicroscopeDissecting 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 - Do not enclose DNA in a nucleus - Always unicellular - Smaller, simpler cells Eukaryotes - Enclose DNA in a nucleus - Can be unicellular or multicellular - Larger, more complex cells