3. Cell scientists outline II.Scientists 1. Anton van Leeuwenhoek 2. Robert Hooke 3. Matthias Schleiden 4. Theodore Schwann II. 3 parts of cell theory III. Vocabulary 1. All cells have: 2. organelle: 3. prokaryote ex. 4. eukaryote ex.

4. Section 7.1 Summary – pages 171-174 The History of the Cell Theory Before microscopes--people believed that diseases were caused by curses and supernatural spirits Microscopes enabled scientists--to view and study cells

5. Section 7.1 Summary – pages 171-174 Anton van Leeuwenhoek—developed first microscope (single lens), observed pond organisms Simple light microscope--contains one lens and uses light to view objects Development of Light Microscopes

6. Compound light microscopes – Uses a series of lenses to magnify objects in steps, can magnify up to 1500X. Section 7.1 Summary – pages 171-174 Development of Light Microscopes

7. Section 7.1 Summary – pages 171-174 Electron microscope--Uses a beam of electrons instead of light to magnify structures up to 500,000x Development of Electron Microscopes - Specimens must be dead to observe under an electron microscope

8. Section 7.1 Summary – pages 171-174 Robert Hooke--Used compound light microscope to study cells in cork. Hooke observed--small shapes he named cells after rooms in a monastery The Cell Theory

9. Unit Overview – pages 138-139Chapter Intro-page 170 Cell--The basic units of all living organisms The Cell Theory

10. Unit Overview – pages 138-139Chapter Intro-page 170 Matthias Schleiden--Concluded that all plants are made of cells Theodor Schwann--Concluded that all animals are made of cells The Cell Theory

11. Rudolph Virchow stated that new cells can be produced only from the division of existing cells (pre-existing cells)

12. Section 7.1 Summary – pages 171-174 Cell theory--developed by discoveries of Hooke, Schleiden, and Schwann All cells come from pre-existing cells. The cell is the basic unit of structure and organization of organisms. All organisms are composed of one or more cells.

13. Cells come in a variety of shapes and sizes. ALL CELLS: 1.Are surrounded by a cell membrane 2. Contain DNA at some point in their lives

14. Microscopes With better microscopes--scientists observed that all cells contain specialized structures called organelles Organelles--Mostly membrane bound structures that have specific functions inside the cell

15. Section 7.1 Summary – pages 171-174 Prokaryotic cells--Cells that do not contain a nucleus or other internal membrane-bound organelles Examples of prokaryotes--Bacteria Two Basic Cell Types Click here

16. Section 7.1 Summary – pages 171-174 Examples of eukaryotes --plants and animals Eukaryotic cells--Cells that contain a nucleus and other membrane-bound organelles 7.1 Two Basic Cell Types Click here

17. A prokaryotic cell does not have internal organelles surrounded by a membrane. Most of a prokaryote’s metabolism takes place in the cytoplasm. 1. Ribosomes 2. DNA 3. Plasma membrane 4. Cell wall Click here to return to chapter summary Chapter Assessment

18. This eukaryotic cell from an animal has distinct membrane-bound organelles that allow different parts of the cell to perform different functions. 4. Plasma membrane 1. Nucleus 2. Nucleolus 3. Chromosomes 5. Organelles Click here to return to chapter summary Chapter Assessment