Journey Through the Microscopic World of Cells

1. Chapter Seven A View of the Cell Free powerpoints at http://www.worldofteaching.com

2. The History of the Cell • The Cell • The basic unit of an organism • Discovery made possible by the invention of the microscope

3. Microscopes and Cells • 1600’s. • Anton van Leeuwenhoek first described living cells as seen through a simplemicroscope.

4. Microscopes and Cells • Robert Hooke used the first compound microscope to view thinly sliced cork cells. • Compound scopes use a series of lenses to magnify in steps. • Hooke was the first to use the term “cell”.

5. Microscopes and Cells • 1830’s. • Mathias Schleiden identified the first plant cells and concluded that all plants made of cells. • - Thomas Schwann made the same conclusion about animal cells.

6. Terminology • Magnification-the process of enlarging something only in appearance, not in physical size • Resolution- the degree of sharpness of an image

7. Today’s Microscopes • Light- aka Compound microscopes are light illuminated. Uses visible light and a system of lenses to magnify images of small samples • The image seen with this type of microscope is two dimensional. This microscope is the most commonly used. You can view individual cells, even living ones

8. Today’s Microscopes • Electron- uses a particle beam of electrons to illuminate a specimen and create a highly-magnified image • Transmission Electron-TEM is electron illuminated. This gives a 2-D view. Thin slices of specimen are obtained. The electron beams pass through this.

9. Today’s Microscopes • Scanning Electron-SEM use electron illumination. The image is seen in 3-D. The specimen is coated in gold and the electrons bounce off to give you and exterior view of the specimen.

10. Cell Theory: • All organisms are made up of one or more cells. • The cell is the basic unit of organization of all organisms. • All cells come from other cells all ready in existence.

11. Cell Size • The ratio between the surface area and volume of cells and organisms has an enormous impact on their biology. • An increased surface area to volume ratio also means increased exposure to the environment • Individual organs in animals are often shaped by requirements of surface area to volume ratio

12. Common Cell Features • Cell Membrane • Cytoplasm • Cytoskeleton • Ribosomes

13. Two Basic Cell Types 1) Prokaryote • Lacks internal compartments. • No true nucleus. • Single-celled (unicellular) organisms. • Cell Wall • Examples: bacteria

15. Kingdoms Ancient Life forms Diseases

16. Type two 2) Eukaryote • Has several internal structures (organelles). • True nucleus. • Either unicellular or multicellular. unicellular example: yeast multicellular examples: plants and animals

17. The Parts of The Eukaryotic Cell:Organelles • Parts of a cell that perform specific functions • All Eukaryotic cells have mitochondria, membrane, nucleus, golgi, endoplasmic reticulum, lysosome, chloroplast, vacuole, ribosome

18. Plants: Chloroplast Cell Wall Central Vacuole

19. ATP Rough: proteins Smooth: Lipids and steroids

20. Other Parts • Cilia- communication, locomotion • Flagella- locomotion • Cytoskeleton- support/anchors, “highways” • Microfibers • Microtubules • Lysosome- digestion • Ribosomes- protein synthesis