1. An Introduction To Cell Biology Chapter 6 in your book Pages 155-181 --> Why are we on chapter 6 already?!

2. Objectives For This Unit 1. Explain the basic tenets of the cell theory 2. Predict the possible effects of improved technology on the study of cells 3. Distinguish between prokaryotic and eukaryotic cell structures. 4. Identify the function of the organelles in a typical eukaryotic cell.

3. Objectives For This Unit 5. Describe the structure of a cell membrane. 6. Compare and contrast the mechanisms for transport of material across the membrane by developing models to illustrate these processes.

4. Objectives For This Unit 7. Summarize the advantages of multi-cellular organization

5. What is the basic unit of life? Biosphere Ecosystem Community Species Population Individual Organ system Organ Tissue Cell Organelle

6. What is the basic unit of life? Biosphere Ecosystem Community Species Population Individual Organ system Organ Tissue Cell Organelle

7. Discoveries that led to the CELL THEORY 1. Robert Hooke - 1665 - slices of cork seen under a microscope.

8. Discoveries that led to the CELL THEORY 2. Anthony Leeuwenhoek (also memorable for his pioneering microscopy) looked at yeast, blood cells, algae, which he thought were tiny animals.

9. Discoveries that led to the CELL THEORY 3. Matthias Jakob Schleiden, a botanist, concluded, “Plants are made of cells!”

10. Discoveries that led to the CELL THEORY 4. Theodor Schwann, a zoologist, concluded, “Animals are made of cells!”

11. Discoveries that led to the CELL THEORY Rudolph Virchow, a pathologist, concluded, “Every living cell comes from a previously living cell!”

12. Psssst… August Weismann connected cell biology with evolution. “All cells can trace their ancestry back to ancient times!”

13. THE CELL THEORY 1. Cells, or products made by cells, are the units of structure and function in organisms. 2. All cells come from preexisting cells. *3. All living things are composed of at least one cell, and cell products

14. Cell Theory: Intepretations Energy flow occurs within cells. Cells contain hereditary information (DNA) which is passed from cell to cell during cell division. All cells are basically the same in chemical composition. The activity of an organism depends on the total activity of independent cells.

15. Macromolecules in the Cell Carbs 1. Carbs : Structure, energy storage Proteins 2. Proteins : Structure, catalysis, movement, messaging, defense, transport Nucleic acids : 3. Nucleic acids : encoding information (Did you realizeATP is actually a nucleotide?) Lipids 4. Lipids : Insulation, concentrated energy and the cellular membrane (Transparency available upon request)

16. How Small Are Cells, Anyway? Smallest cells (prokaryotes) - one micron One micron or micrometer = one-millionth of a meter Most cells are 10-20 microns in diameter. Human red blood cells - 10 microns Unicellular organisms - 100 microns Fish egg - 1 millimeter Ostrich egg yolk - 100 mm Giraffe nerve cell - 7 m!!

17. So How Are We Supposed To See Them!? “ Predict the possible effects of improved technology on the study of cells.” That is, what do you think we will be able to discover? Light microscopes Transmission electron microscopes Scanning electron microscopes

18. Electron Microscopes Drawbacks Extremely expensive Specimen can’t be alive Can’t see moving processes 1. Coat with heavy metals, gold, or carbon 2. Fire electrons at specimen 3. Record image on a computer

19. Electron Microscopes Transmission EM Black and white image Magnification = 250,000X Resolution = 1 nm To see inside cells (INSIDE) Scanning EM 3D imagery Magnification = 100,00X Resolution = 10 nm To see organs of small organisms (OUTSIDE)

20. What Have We Covered? Next: Proks vs Euks Organelles Animals vs Plants Cell Membranes and Membrane Transport Multicellularity