1. The Cell

2. 7.1 Cell discovery and cell theory  How do we study cells?  With MICROSCOPES!!!!!!

3. 7.1 Objectives  Identify the parts of a microscope  Match scientists with key discoveries  Compare light and electron microscopes  Identify the 3 parts of cell theory  Explain the main differences between eukaryotic and prokaryotic cells

4. Compound Light Microscopes (what we will use)

6. The guys who started it all…  Zacharias and Hans Janssen invent the world's first 2 lens ( compound) microscope in 1590.

7. The guys who started it all…  1665 Robert Hooke  Looking at cork  Chambers ( named them cells)  Anton van Leeuwenhoek  Single lens microscope  Pond water  1 st to discover living cells “animalcules” (protists)

8. Why the long gap between inventions?  Few advancement in the mid 19 th century  Spontaneous Generation (widely accepted, traditional belief that life arises from nonlife)  Examples:  Mice were created from damp hay and corn in a dark corner  Maggots/Flies came from rotting meat  Mud could give rise to worms, insects, and fish

9. 19 th Century Advancement  Spontaneous Generation = doubters  Louis Pasteur  Disproved and replaced theory with…  Theory of Biogenesis (states that only living organisms can produce other living organisms )  Designed an experiment to show this was true even for microorganisms

10. Development of the Cell Theory  Matthias Schleiden: (1838- German Botanist)  plant parts are made of cells  Theodor Schwann: (1839- German physiologist)  animal tissues are composed of cells.

11. Johannes Purkinje (1840)  First to observe cell division  First to observe the living contents of a cell

12. Development of the Cell Theory  Rudolf Virchow (1858- German physician)  concluded that cells must arise from preexisting cells

13. Because of them, today we have…

14. Advancing technology  Light microscopes

15. Electron microscopes  Early 1900’s  Higher resolution

16. Scanning probe microscopy

17. Fluorescence and light microscopy  Uses fluorescence and phosphorescence in addition to, reflection and absorption

18. What do you know about cells?

19. Cell Theory: 3 parts  1. All living things are made of cells  Composed of cells (Matthis Schleiden 1838- plants were made of cells; Theodor Schwann 1839-animals too!)  2. Cells are basic unit of structure and function of living things  3. New cells are made from existing cells  (Rudolf Virchow 1855)

20. All Cells…  Surrounded by a cell barrier (cell membrane)  Carry biological information at some point ( DNA)  Vary in size and shape

21. Two different types  Prokaryotic and Eukaryotic

22. Prokaryotic vs. Eukaryotic ProkaryotesEukaryotes “Pro” = Before Karyon = nucleus “E = True Karyon = nucleus True nucleus Size: Large/Complex Membrane bound organelles Membrane bound nucleus with linear DNA Some have cell walls Multicellular or unicellular Found in Kingdoms: Animalia Plantea Protista Fungi No true nucleus Size: Small/primative No membrane bound organelles DNA is small and in a ring Cell wall Unicellular-colonies Free Ribosomes (small) Found in Kingdoms: Archaea Bacteria