1. Lecture 2 Anatomy and Physiology of Prokaryotic and Eukaryotic Cells

2. Prokaryotic Cells

3. Bacterial Shape and Arrangement

4. Streptococcus chain © Dr. David M. Phillips/Visuals Unlimited

5. Sarcinae cube © David B. Fankhauser, University of Cincinnati, http://biology.clc.uc.edu/Fankhauser/

6. Staphylococcus aureus cluster © Dr. Fred Hossler/Visuals Unlimited

7. Spiral-shaped bacterial cell © Michael Abbey/Visuals Unlimited

8. Prokaryotic Cell Structure

9. Cytoplasmic Membrane Surrounds cytoplasm and defines boundaries of cell Acts as barrier, but also functions as an effective and highly discriminating conduit between cell and surroundings Made up of phospholipid bilayer

10. Figure 4.14c

11. Phospholipid

12. Figure 4.14b

13. Movement of Molecules through Cytoplasmic Membrane Several ways for molecules to move through membrane 1.Simple Diffusion 2.Osmosis 3.Facilitated Diffusion 4.Active Transport

14. Simple Diffusion Does not require expenditure of energy Process by which some molecules move freely into and out of the cell Small molecules such as carbon dioxide and oxygen

15. Microbiology: An Introduction, 9e by Tortora, Funke, Case Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 4.18: The principle of osmosis - Overview. (a) At beginning of osmotic pressure experiment (b) At equilibrium (c) Isotonic solution — no net movement of water (d) Hypotonic solution — water moves into the cell and may cause the cell to burst if the wall is weak or damaged (osmotic lysis) (e) Hypertonic solution — water moves out of the cell, causing its cytoplasm to shrink (plasmolysis) Glass tube Rubber stopper Rubber band Sucrose molecule Water molecule Cellophane sack Cytoplasm SolutePlasma membrane Cell wall Water

16. Transport Proteins Transport proteins (or transporters) responsible for: Facilitated Diffusion Active Transport

17. Microbiology: An Introduction, 9e by Tortora, Funke, Case Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 4.17: Facilitated diffusion. Transported substance Transporter protein Outside Inside Glucose Plasma membrane

18. Cell Wall Composed of peptidoglycan Comprised of alternating NAG and NAM molecules Attached to each NAM is four amino acid peptide: tetrapeptide

20. Categories of Bacteria Two Major Categories: Difference due to difference in chemical structures of their cell walls –Gram positive: stains purple –Gram negative: stains red

21. Gram + Cell Wall Thick Layer of Peptidoglycan Contains techoic acid: chains of ribitol- phosphate or glycerol-phosphate to which sugars or alanine attached Techoic Acid sticks out above the peptidoglycan layer

24. Gram – Cell Wall More complex than Gram + cell wall Thin layer of peptidoglycan –Sandwiched between the cytoplasmic membrane and outer membrane Outside of peptidoglycan is outer membrane

25. Figure 4.13c

26. Outer Membrane Unlike any other membrane in nature A lipid bilayer with the outside layer made of lipopolysaccharides instead of phospholipids Also called LPS Contains Porins

28. Periplasm - Region between cytoplasmic membrane and the outer membrane - Gel-like fluid Filled with secreted proteins and enzymes

29. External Structures Glycocallyx Flagella Axial Filaments Fimbrae and Pili

30. Glycocallyx Gel-like structure –Functions in protection and attachment –Two types- capsule and slime layer –Involved in attachment, enabling bacteria to stick to teeth, rocks –Enables bacteria to brow as biofilm

31. Capsule in Acinetobacter species by gram negative staining Courtesy of Elliot Juni, Department of Microbiology and Immunology, The University of Michigan

32. Filamentous Protein Appendages Anchored in membrane and protrude from surface Flagella: long structure responsible for motility Fimbrae and Pili: shorter, responsible for attachment

33. Four types of bacteria with flagella Montrichious- one flagella Amphitrichous- flagella at both ends Lophitrichous- many flagella at the end of the cell Peritrichous- flagella all over entire cell

34. Figure 4.7 - Overview

35. Movement of Bacteria

37. Axial Filament Present in Spirochetes Attach at end of cell, spiral around, underneath an outer sheath Move like a corkscrew

38. Figure 4.10 - Overview

39. Fimbrae and Pili Shorter and surround the cell Similar structural theme to filament of flagella Fimbrae- enable cell to adhere to surfaces, including other cells Pili- join bacterial cells in preparation for the transfer of DNA from one cell to another

41. Internal Structures of Prokaryotic Cells

42. Cytoplasm Substance of cell inside the cytoplasmic membrane About 80% water Thick, aqueous, semitransparent, elastic

43. Chromosome Found within a central location known as nucleoid Single, circular, double stranded Consists of all DNA required by cell

45. Plasmids Some bacteria contain plasmids- small circular double-stranded DNA Typically cell does not require genetic information carried on plasmid However, it may be advantageous

46. Ribosomes Site of protein synthesis Relative size and density of ribosomes and their subunits expressed as distinct unit (S) Two units of prokaryotic ribosomes: 50S + 30S= 70S Eukaryotic ribosomes: 80S

47. Microbiology: An Introduction, 9e by Tortora, Funke, Case Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 4.19: The prokaryotic ribosome. (a) Small subunit(b) Large subunit(c) 50S 30S (c) Complete 70S ribosome

48. Inclusions Store excess nutrients Examples: Polysaccharide granules- glycogen and starch Lipid inclusions Metachromatic granules- inorganic phosphate that can be used to synthesize ATP

50. Endospores Occurs in members of genera Bacillus and Clostridium Dormant cell produced by a process called Sporulation Germination- when they exit the dormant state and then become a vegetative cell Several species of endospore formers can cause disease

53. Eukaryotic Cells

54. Plasma Membrane Very similar in structure and function to cytoplasmic membrane of prokaryotes Differences in types of proteins found in membranes Also contain carbohydrates, sterols

55. External Structures Cell wall: much simpler then prokaryotic cell walls, no peptidoglycan Glycocallyx: sticky carbohydrate Flagella: long in relation to size of cell Cilia: numerous and short

56. Internal Structures Cytoplasm Ribosomes Organelles

57. Ribosomes Attached to surface of endoplasmic reticulum or free floating 40S + 60S  80S

58. Organelles Structures with a specific shape and specialized function Nucleus: DNA found here Endoplasmic reticulum Golgi complex Lysosomes Mitochondria: ATP production