1. Honors Biology Ch. 7 Cellular Structure and Function

2. CH. 7Cell Structure and Function A. History -before 1600 ’s - fiber / tissue thought to be the basic unit of life -spontaneous generation 1.Robert Hooke (1665) - observed cork cells I.The Cell Theory:

3. Robert Hooke (1665) - Coined term ‘Cell’

4. 2.Van Leeuwenhoek (1683) - first to see living cells

5. Van Leeuwenhoek (1683) - first to see living cells Van Leeuwenhoek (1683) - first to see living cells

6. 3.Mathias Schleiden (1838) -plants made of cells

7. 4.Theodor Schwann 4.Theodor Schwann (1838) -animals made of cells

8. 5.Rudolph Virchow 5.Rudolph Virchow (1855) -cells come from other cells

9. B.The Cell Theory (3 parts): 1.All living things are made of cells. 2.All cells come from preexisting cells. 3.Cells are the basic units of structure and function. -developed over several hundred years involving many scientists -followed the development of the microscope

10. Research Method: Light Microscopy TECHNIQUERESULTS Brightfield (unstained specimen). Passes light directly through specimen. Unless cell is naturally pigmented or artificially stained, image has little contrast. [Parts (a)–(d) show a human cheek epithelial cell.] (a) Brightfield (stained specimen). Staining with various dyes enhances contrast, but most staining procedures require that cells be fixed (preserved). (b) Phase-contrast. Enhances contrast in unstained cells by amplifying variations in density within specimen; especially useful for examining living, unpigmented cells. (c) 50 µm

11. Differential-interference-contrast (Nomarski). Like phase-contrast microscopy, it uses optical modifications to exaggerate differences in density, making the image appear almost 3D. Fluorescence. Shows the locations of specific molecules in the cell by tagging the molecules with fluorescent dyes or antibodies. These fluorescent substances absorb ultraviolet radiation and emit visible light, as shown here in a cell from an artery. Confocal. Uses lasers and special optics for “optical sectioning” of fluorescently-stained specimens. Only a single plane of focus is illuminated; out-of-focus fluorescence above and below the plane is subtracted by a computer. A sharp image results, as seen in stained nervous tissue (top), where nerve cells are green, support cells are red, and regions of overlap are yellow. A standard fluorescence micrograph (bottom) of this relatively thick tissue is blurry. 50 µm (d) (e) (f)

12. Micrograph of a neuron and dendrites using antibodies, fluorescent proteins, and confocal microscope

13. Research Method: Electron Microscopy TECHNIQUERESULTS Scanning electron micro- scopy (SEM). Micrographs taken with a scanning electron micro- scope show a 3D image of the surface of a specimen. This SEM shows the surface of a cell from a rabbit trachea (windpipe) covered with motile organelles called cilia. Beating of the cilia helps move inhaled debris upward toward the throat. (a) Transmission electron micro- scopy (TEM). A transmission electron microscope profiles a thin section of a specimen. Here we see a section through a tracheal cell, revealing its ultrastructure. In preparing the TEM, some cilia were cut along their lengths, creating longitudinal sections, while other cilia were cut straight across, creating cross sections. (b) Cilia 1 µm Longitudinal section of cilium Cross section of cilium 1 µm

14. Everything that lives is made of cells.

15. C.Two Basic Cell Types: 1.Prokaryotes: -no nucleus nor organelles -simple internal structure -very small, primitive, unicellular -bacteria

16. ProkaryoteProkaryote Bacteria Cell

17. 2.Eukaryotes: -have a nucleus and membrane- bound organelles -complex internal structure -animals, plants, fungi, protists

18. EukaryoteEukaryote Animal Cell

19. EukaryoteEukaryote Plant Cell

20. II.Cell Structure A.Plasma membrane: - bilayer of phospholipids embedded with proteins - “fluid mosaic” theory

21. -holds cell together -regulates movement of molecules into or out of the cell

22. Cell Wall -rigid, layered structure on the outside of cells that protects and supports cell -in plants, fungi, and bacteria -made of cellulose (in plants)

23. Cell Wall

24. B.Nucleus: -control center of the cell -contains chromatin (DNA “blueprint” for cell’s proteins) -Nucleolus: makes ribosomes

25. Organelles Cytoplasm -liquid interior of the cell -mostly water with dissolved substances (O 2,CO 2, sugar, etc.) -contains organelles C.Cytoplasm

26. D.Assembly, Storage, and Transport 1.Ribosomes: - site of protein synthesis

27. 2.Endoplasmic Reticulum: - produces and transports molecules

28. 3.Golgi Body: -store, modify, and package proteins, hormones, etc.

29. Processing a Protein from Rough Endoplasmic Reticulum to Golgi Body to a Secretory Vesicle

30. - stores food, waste, sugar, water, etc. 4.Vacuole:

31. 5.Lysosome: -digest food molecules or worn-out cell parts

32. 6.Leucoplasts: -store starch (in plants) leucoplast

33. 7.Chromoplasts: -contain colorful pigments (in plants) chromoplasts

34. Energy Transformations E.Energy Transformations 1.Mitochondria: - "power house" of cells - site of cellular respiration

35. -site of photosynthesis in plant cells 2.Chloroplasts:

36. F.Support and Locomotion 1.Cytoskeleton - internal framework of cell

37. F.Support and Locomotion 1.Cytoskeleton - internal framework of cell

38. F.Support and Locomotion 1.Cytoskeleton - internal framework of cell a.Microtubules - provide support b.Microfilaments - contractile proteins - enable cells to move

39. 2.Centrioles -aid in the division of animal cells

40. 3.Cell Locomotion a.Cilia: -short fibers b.Flagella: -long fibers

41. III.Cellular Transport -molecules constantly enter and leave the cell

42. A.Diffusion Crystal of dye placed in water Diffusion of dye and water molecules Equilibrium reached -movement of molecules from high concentration to low conc. - requires no cell energy (passive)

43. B.Osmosis: -diffusion of water through a selectively permeable membrane Concentrated sugar solution (water less concentrated) Diluted sugar solution (water more concentrated) Sugar molecules Selectively permeable membrane Movement of water

44. C.Effects of Osmosis 1.Isotonic Solution -concentration of solutes the same on inside and outside of cell Animal Cell Plant Cell

45. 2.Hypotonic Solution -solution outside of cell contains a lower conc. of solutes than the cell (more water) Animal Cell Plant Cell

46. a)Turgor pressure: - pressure inside plant cells

47. Leaves and Onion Epidermis a)Turgor pressure:

48. Plant Movements from Osmosis a)Turgor pressure:

49. b) Cytolysis: -bursting of cells due to increased osmotic pressure

50. c)Contractile Vacuoles: -“pump” water out of cells of ameba, paramecium, etc. living in a hypotonic solution Paramecium

51. 3.Hypertonic Solution -solution outside of cell contains a higher conc. of solutes than the cell (less water) Animal Cell Plant Cell

52. a) Plasmolysis: -loss of cytoplasm (shrinking of the cell)

53. b) Wilting: - loss of turgor in plant cells

54. D.Passive vs. Active Transport 1.Passive Transport: - requires no cell energy a)Diffusion and Osmosis b) Facilitated Diffusion: - transport proteins in membrane move sugar, amino acids, etc. - follows concentration gradient

55. b) Facilitated Diffusion:

56. 2.Active Transport: - requires cell energy a)Carrier proteins - transport molecules from low conc. to high conc. using cell energy

57. Active Transport:

58. b)Endocytosis:

59. -movement of large amounts of material into a cell by engulfing and enclosing within a membrane - forms a vacuole within cell

60. b)Endocytosis: Ameba

61. c)Exocytosis: -expelling large amounts of material from the cell

62. c)Exocytosis: Paramecium

63. Active and Passive Transport Animation (6:13) Active and Passive Transport Animation (6:13)

64. Voyage Inside the Cell (14:51) Voyage Inside the Cell (14:51)

65. The End The End

66. Moss (Mnium) Leaf Cells

67. Tomato Cells

68. Potato Cells

69. Human Epithelial Cells

70. Bacteria Cells CoccusBacillusSpirillum

71. Onion Cells- Unstained (40x)

72. Onion Cells- Stained (40x)

73. Elodea Leaf Cells