1. Prokaryotic vs. Eukaryotic Cells

2. Major Cell Types Prokaryotic –(Bacteria and archaea) cells lack a membrane-bounded nucleus or membrane-bounded organelles. Eukaryotic –cells have a membrane-bounded nucleus and membrane-bounded organelles.

3. Prokaryotes Archaea Extreme halophiles Extreme thermophiles Methanogens Bacteria Cyanobacteria (blue-green algae)

4. Prokaryotic Characteristics  Strong Cell Wall  Rotating Flagella  Simple Interior Organization

5. Cell Walls  With peptidoglycan –Bacteria  Without peptidoglycan –Archaea –Plants –Fungi –Most protists

6. Rotating Flagella  Protein fibers  0, 1 or more  Rotary “motor” uses proton gradient for energy

7. Simple Internal Organization  No membrane-bound nucleus  No membrane-bound organelles  Plasma membrane carries out some “organelle” functions –DNA separation –Folds containing pigments for photosynthesis

8. Botulism!

9. Cholera!

10. Black Death!

11. Flesh Eating Bacteria!

12. E. coli!

13. All caused by... Bacteria!

14. Bacteria Size: 1-1.4  m wide, 2-6  m long Shapes:spherical (coccus) rod-shaped (bacillus) spiral (spirillum)

15. Bacterial Morphology

16. Key Bacteria Features  Cell wall – peptidoglycan strengthens  Capsule/slime layer (glycocalyx)  Flagellum – motility appendage  Plasma membrane  Cytoplasm (cytosol)  Ribosomes  Nucleloid  Plasmids  Thylakoids  Sex pili

17. Bacteria Most bacteria living today “true bacteria.” CStrong cell walls containing peptidoglycan (protein cross-linked carbohydrate ) (protein cross-linked carbohydrate ) CSimple gene architecture CPhotosynthetic - cyanobacteria (blue-green algae) CFolded plasma membrane CFolds contain photosynthetic pigments

18. Representative Prokaryotic (Bacterial) Cell

19. Archaea From the Greek for “ancient ones.” Anaerobic (“without air”) Similarities to bacteria  DNA  Lipid cell membrane  Exterior cell wall  Metabolism based on ATP

20. Archaea Differences from bacteria  Also lobed, plate-shaped or simply irregular  DNA & RNA sequences closer to eukaryotes  Inhabit extreme environments  Lack peptidoglycan in cell walls  Unique lipids in cell membrane  Differences in basic biochemical processes

21. Eukaryotic Cells Far more complex! BioFlix: Tour Of An Animal Cell BioFlix: Tour Of An Animal Cell BioFlix: Tour Of A Plant Cell BioFlix: Tour Of A Plant Cell

22. Key Eukaryotic Cell Features  Membrane-bound nucleus –chromosomes  Membrane-bound organelles –Compartmentalization  Cytoskeleton

23. Review  Identify the major characteristics that distinguish a cell as being prokaryotic.

24. Review  Define the following key terms related to prokaryotic cells. cytosolnucleoid region capsuleslime layer cell wallcapsule flagellumplasma membrane cytoplasm (cytosol)ribosomes nucleloidplasmids thylakoidsglycocalyx