2. Cell Structure and Function

3. The Cell  the basic unit of life and organisms  discovery made possible by the invention of the microscope

4. 1-Galileo Galilei  arranged two glass lenses within a cylinder; was the first to record observations through a microscope.

5.  He took slices of cork from a tree, observed the tiny compartments, and gave them the name, cellulae (cell).

6.  Used a microscope to view pond water and discovered what we know today as single-celled organisms.

7.  Notices opaque spots in cells and named them nucleus.

8.  Concluded that all plants are made of cells.  Plant cells develop as independent units even though they are part of a plant.

9. 6-Theodor Schwann (Zoologist)  Concluded that all animals were made of cells.  Animal cells develop as independent units even though they are part of the animal.

10.  Determined that cells come from other cells.

11. The observations of Schleiden, Schwann, and Virchow formed the Cell Theory.

12. cell theory - is a scientific theory which describes the properties of cells.

13. 1. All organisms are made of cells. 2. The cell is the most basic unit of life. 3. All existing cells are produced from other living cells.

15. Characteristics  DO NOT HAVE internal compartments, structures, or organelles.  Have a cell wall  Single-celled organisms  Relatively small and simple  Can not carry out many specialized functions.  Bacteria are the only Prokaryotes!

16. Eukaryotes- HAVE a nucleus Characteristics  HAVE internal compartments, structures, and organelles.  Single-celled (Protists) and multicellular organisms  Plants and Fungi – have a cell wall; Animals – do not have a cell wall; Protist - mixed (some have cell walls and others do not)  Organelles allow cells to carry out specific (specialized) functions.  Animals, Fungi, Plants, and Protists  are Eukaryotes!

17. All cells have 1. Cell membrane (plasma membrane):  A phospholipid bilayer that regulates what enters and leaves the cell. 2. Cytoplasm:  Fluid substance between the cell membrane and the DNA region.

18. 3. DNA containing region  Prokaryote cells-a circular piece of DNA called plasmid.  Eukaryote cells-genetic material is in the nucleus. 4. Cytoskeleton:  network of protein fibers in the cytoplasm that give structure and support to the cell. 5. Ribosome:  cell structures that make proteins.