1. In the beginning…….
1665—Robert Hooke, British scientist, looked at a thin slice of cork using a primitive microscope
“little boxes” reminded him of monastery cells, so he named what he saw CELLS

2. 10 years later…..
Antoine Von Leeuwenhoek (Dutch linen merchant) discovered “tiny animals” in supposedly clean pond water, using a scope that he designed---we now call these organisms: ___________
Was first to discover that there were tiny swimming cells (sperm) in semen

3. ~ 160 years later three Germans arrived at several conclusions….
1838—Schleiden proclaimed, after much research, that cells are in all parts of plants
1839—Schwann announced that animals have cells in all their parts
1858—Virchow reported that cells only come from other living cells—yes, people used to believe in abiogenesis!

4. CELL THEORY All living things are composed of 1 or more cells
Cells are the basic units of structure & function in organisms
Cells are produced only from existing cells

5. Common characteristics of all cells
Cell/plasma membrane —separates the cell’s insides from its environment; regulates what comes in/leaves the cell, which maintains HOMEOSTASIS—balance between the inside/outside of cell
Cytoplasm—everything inside the cell, minus the genetic material
Cytosol—fluid part of the cytoplasm
Ribosomes—structures on which proteins are made; composed of RNA and proteins; very tiny—didn’t even know they were in cells until electron microscopes “discovered” them ~ 1940’s

6. Short history of cells
First/oldest cells are prokaryotes (before kernel)
single-celled organisms (ie bacteria) that do not have membrane-bound compartments w/in the cell
Very tiny (1-15 µ)
Genetic material is a single, circular strand that floats inside the cell
Only living organisms for our planet’s first 2 billion years

7. Endosymbiosis Theory Theory about how more complex cells came about
One prokaryote either invaded or was engulfed by another prokaryote
Neither cell died—they lived and benefited from each other
When they reproduced they both split and stayed together, making 2 cells each with another cell inside
Cell inside either became the nucleus or the mitochondria…..more on those later
Endosymbiosis Theory

9. Bacteria 3 shapes: coccus, bacillus, spirillum Coccus—round
Diplococcus—attached pairs
Streptococcus—attached long chains
Staphylococcus—grape-like bunches

10. BACTERIA, cont. Bacillus—rod shaped Diplobacillus—2 attached
Streptobacillus—long chains

11. BACTERIA, AGAIN Spirillum—3 distinct shapes Vibrio—comma shaped
Spirillum—thick, rigid spiral
Spirochete—thin, flexible spiral

12. Bacteria…cont.
Pathogens—disease causing bacteria; how many diseases can you name??
Colony—visible group of microorganisms derived from one individual
Shape: circular, lobate, rhizoids
Elevation: flat, raised, convex, fuzzy
Color: surprisingly varied
Matte vs Shiny