1. Chapter 3

2. Cells Under the Microscope Anton van Leeuwenhoek (1632- 1723) - First to see “animalcules” in pond water

3. The Cell Theory  1. All living things are made of one or more cells.  2. Cells are the basic unit of structure & function of all living things.  3. All cells arise from existing cells.

4. Cell Size  Small cells More efficient Higher surface area-to-volume ratio

5. All Cells Have  Plasma Membrane: Selective outer boundary  Cytoplasm: Water-like interior  DNA: Genetic material  Ribosomes: Synthesize Proteins

6. Two Basic Cell Types ProkaryoteEukaryote SizeSmallLarge DNAIn “nucleoid” regionWithin membrane-bound nucleus OrganellesNo organellesMembrane-bound organelles Body TypeUnicellularUnicellular or Multicellular NutritionHeterotropic or Autotrophic Heterotrophic or Autotrophic KingdomsBacteria & ArchaeaProtista, Fungi, Plantae, & Animalia

7. Prokaryote  Bacteria  Smallest simplest cells  Cell Wall: Surrounds cell membrane & provides structural support  Flagellum: Long threadlike structures that enable movement

8. Organelle  Membrane-bound structure that carries out specific activities for the cell.

9. They Both Have

10. Nucleus  Contain DNA  Nuclear Envelope: Membrane surrounding nucleus  Nucleolus: Where ribosomes are made

11. Endoplasmic Reticulum (ER)  Membrane bound  Rough ER: Contains Ribosomes Synthesizes Proteins  Smooth ER: Makes Lipids Breaks down toxic substances

12. Golgi Apparatus  Golgi packages & distribution center for cell.  Vesicles: small membrane bound sacs that transport substances around the cell.

13. Mitochondria  Makes ATP from breaking down food  Cells that need lots of energy have lots of mitochondria. (muscle cells)  Surrounded by membranes, contain DNA & ribosomes, and are thought to be descendents of prokaryotic cells (endosymbiosis)

14. Lysosomes  Contains special enzymes for digestion in the cell.

15. Animals Cells Can Have  Cilia: Hair-like structures used for cell movement  Flagella: Like those found in bacteria

16. Plant Cells

17. Chloroplasts  Uses light energy to make carbohydrates from water and carbon dioxide.  Provide energy for cell.  Surrounded by double membrane, contains DNA, thought to be descendents of prokaryotic cells. (endosymbiosis)

18. Cell Wall  Surrounds & supports Cell  Maintains cell shape  Protects  Connects to other cells

19. Central Vacuole  Large membrane bound sac that stores water & other substances  When full makes cell rigid enables plants to stand upright

20. Cell Analogy