Chapter 7-Section 1 The Discovery of Cells

1. Chapter 7-Section 1The Discovery of Cells

2. History of the Cell Theory • B/f microscopes disease believed to be caused by curses and supernatural spirits • Bacteria & microorganisms unknown • Invention & use of microscopes lead to a new world of microoroganisms & the idea of the cell • Cell-def p171-the basic units of living organisms

3. Light Microscopes i) Improvement of Microscope = better understanding of microorganisms & cells • 1st microscope was used by Anton van Leeuwenhoek in 1600s • Improvement of microscopes • Higher quality lenses • Development of compound microscope • Compound Microscope-def p171-a microscope that uses a series of lenses to magnify objects in steps • Can magnify up to 1500x • Microscope established as validate scientific tool • Can draw conclusions about organization of living matter • Relate actual size to magnified size

4. Parts of the microscope

5. Cell Theory • Robert Hooke & His discoveries • English Scientist & used microscope to look at cork (dead cells of oak bark) • Observed box-like structures & named them cells-after rooms in a monastery • Concluding idea-Cells are the basic unit of life

6. Cell Theory • Expanding on Hooke’s ideas • 1830s- Matthias Schleiden-German scientist-observed plants • Concluding idea- all plants are composed of cells • 1830s-Theodor Schwann-1839-was studying animals • Concluding idea- all organisms are made of cells.

7. Cell Theory • 3 main ideas of Cell Theory • All organisms are composed of one or more cells • Organisms can be multicellular (many celled organism) (i.e.-humans, dogs,etc.) • Organisms can be unicellular (one celled organism) (i.e.-amoeba) • The cell is the basic unit of structure and organization of organisms • Cell is always the most basic component of any organism • All cells come from preexisting cells • Cell theory was what informed people about the cells come from. • Cells divides to form 2 identical cells

8. Electron Microscopes • 1930s-1940s-new microscope developed-Electron Microscope • Electron Microscope-def-pg172-a microscope that uses a beam of electrons instead of light to magnify structures up to 500,000X their actual size • This type of microscope allowed scientists see structures inside cells • Specimens must be looked at in a vacuum

9. Electron Microscope • 2 basic type of electron microscopes: • SEM (Scanning Electron Microscope)- microscope used to scan the surface of cells to learn their 3-D shape • TEM(Transmission Electron Microscope)-microscope that allows scientists to study the structures contained within cell • New Advances in Microscope • STM (Scanning tunneling microscope)-a microscope that uses the flow of electrons to create computer images of atoms on the surface of a molecule

10. Two basic cell types • Better microscopes = observation of more specialized parts of the cell • Organelles-def p173-small specialized structures found in all cells • Surrounded by membranes • Each organelle has special fxn • 2 basic Cell Types: • Prokaryotes-def p173-cells that don’t contain membrane bound organelles and have no nucleus • No membrane bound organelles • No nucleus • Ex/ unicellular organisms- bacteria • Eukaryotes-def-173- cells that contain membrane bound organelles and have a nucleus • Has membrane bound organelles • Has a nucleus • Ex/ multicellular organisms-amoebas, yeast, algae • Eukaryotes vs. Prokaryotes • Benefits of membrane bound organelles: • Separation of cell fxn into distinct compartments • Chemical rxns that can happen simultaneously • Organelle & Organelle Fxn • Nucleus-def-p174- the central membrane bound organelle that manages or controls cellular fxn