1. Ch. 6.1: Cell Theory Objectives  Explain the main ideas of cell theory.  Describe how microscopes aid the study of cells.  Distinguish between prokaryotic and eukaryotic cells.  Compare and contrast plant and animal cells.  Vocab.  Cell theory  Organelle  Plasma membrane  Nucleus  Cytoplasm  Cell wall  Prokaryotic cell  Eukaryotic cell

2. Developing Cell Theory Robert Hooke (1665) Observes “compartments” in cork (dead plant cells)…names them “CELLS” Anton von Leeuwenhoek (1700) Observes living organisms in pond water

3. Cell Theory (mid 1800s) All living things are composed of cells. Cells are the basic units of structure and function in living things. New cells are produced from pre- existing cells.

4. Modern Microscopes 1. Light Microscope  1000x mag.  Uses lenses & light  Bacteria cells & larger.  Most organelles not visible.  Live specimens

5. Modern Microscopes 2. Scanning Electron Microscope (SEM)  Up to 10 6 mag.  Bounces beam of electrons off of surfaces  Surface features only  No live specimens

6. Prokaryotes v. Eukaryotes Prokaryotes  Bacteria & Archae life forms  Lacks nucleus  DNA is “free” in cytoplasm  Lack most organelles; Has ribosomes & cell wall  Small size (1-10 um)  Simplier Eukaryotes  Plant & Animal cells  DNA in nucleus w/ nuclear membrane  Many organelles  Larger size (10 - 100 um)

7. Eukaryotic Cells: Animal v. Plant Plant 1. Cell walls (protects & gives shape) 2. Chloroplast (contains photosynth. Pigments) 3. Large central vacuole (store water and dissolved minerals) Animal  Centrioles (used in cell division)  Cytoskeleton (filaments for shape & movement)  Flagella (motion)

8. Eukaryotic Cells: Animal v. Plant Plant Animal

9. All Cells Eukaryotes  Plasma (Cell) Membrane  Cytoplasm  Ribosomes Prokaryotes