1. Organization of the Cell Organization of the Cell Chapter 4

2. Learning Objective 1 What is cell theory? What is cell theory? How does cell theory relate to the evolution of life? How does cell theory relate to the evolution of life?

3. Cell Theory (1) Cells are basic units of organization and function in all living organisms (2) All cells come from other cells All living cells have evolved from a common ancestor

4. Learning Objective 2 What is the relationship between cell organization and homeostasis? What is the relationship between cell organization and homeostasis?

5. Homeostasis Cells have many organelles, internal structures that carry out specific functions, that help maintain homeostasis Cells have many organelles, internal structures that carry out specific functions, that help maintain homeostasis

6. Plasma Membrane Plasma membrane Plasma membrane surrounds the cell surrounds the cell separates cell from external environment separates cell from external environment maintains internal conditions maintains internal conditions allows the cell to exchange materials with outer environment allows the cell to exchange materials with outer environment

7. Learning Objective 3 What is the relationship between cell size and homeostasis? What is the relationship between cell size and homeostasis?

8. Biological Size

9. Surface to Volume Ratio SVR SVR ratio of plasma membrane (surface area) to cell’s volume ratio of plasma membrane (surface area) to cell’s volume regulates passage of materials into and out of the cell regulates passage of materials into and out of the cell Critical factor in determining cell size Critical factor in determining cell size

10. SVR

11. Learning Objective 4 What methods do biologists use to study cells? What methods do biologists use to study cells? How are microscopy and cell fractionation used? How are microscopy and cell fractionation used?

12. Microscopes Light microscopes Light microscopes Electron microscopes Electron microscopes superior resolving power superior resolving power

13. Microscopes

14. Fig. 4-4a, p. 79 Light source Light microscope Light beam Ocular lens Objective lens Specimen Condenser lens (a) A phase contrast light microscope can be used to view stained or living cells, but at relatively low resolution. 100 μm

15. Fig. 4-4b, p. 79 Projector lens (electromagnetic) Transmission electron microscope Electron gun Electron beam First condenser lens (electromagnet) Specimen Film or screen (b) The transmission electron microscope (TEM) produces a high- resolution image that can be greatly magnified. A small part of a thin slice through the Paramecium is shown. 1 μm

16. Fig. 4-4c, p. 79 Electron gun Electron beam First condenser lens (electromagnet) Secondary electrons Scanning electron microscope Second condenser lens Scanning coil Final (objective) lens Cathode ray tube synchronized with scanning coil Electron detector Specimen 100 μm (c) The scanning electron microscope (SEM) provides a clear view of surface features.

17. Cell Fractionation Cell fractionation Cell fractionation purifies organelles purifies organelles to study function of cell structures to study function of cell structures

18. Cell Fractionation

19. Learning Objective 5 How do the general characteristics of prokaryotic and eukaryotic cells differ? How do the general characteristics of prokaryotic and eukaryotic cells differ? How are plant and animal cells different? How are plant and animal cells different?

20. Prokaryotes Prokaryotic cells Prokaryotic cells No internal membrane organization No internal membrane organization nuclear area (not nucleus) nuclear area (not nucleus) cell wall cell wall ribosomes ribosomes flagella flagella

21. Prokaryotes

22. Animation: Typical Prokaryotic Cell CLICK TO PLAY

23. Eukaryotes Eukaryotic cells Eukaryotic cells membrane-enclosed nucleus membrane-enclosed nucleus cytoplasm contains organelles cytoplasm contains organelles cytosol (fluid component) cytosol (fluid component)

24. Animal Cells

25. Fig. 4-8, p. 83 Lysosome Ribosomes Rough ER Smooth ER CentriolesMitochondrion Rough and smooth endoplastic reticulum (ER) Nuclear envelope Nucleolus Nucleus Chromatin Nuclear pores Nuclear envelope Membranous sacs of Golgi Golgi complex Plasma membrane Cristae

26. Plant Cells Plant cells Plant cells rigid cell walls rigid cell walls plastids plastids large vacuoles large vacuoles no centrioles no centrioles

27. Plant Cells

28. Animation: Plant Cell Walls CLICK TO PLAY

29. Learning Objective 6 What are the three functions of cell membranes? What are the three functions of cell membranes?

30. Cell Membranes Divide cell into compartments Divide cell into compartments Vesicles transport materials between compartments Vesicles transport materials between compartments Important in energy storage and conversion Important in energy storage and conversion Endomembrane system Endomembrane system

31. Animation: Common Eukaryotic Organelles CLICK TO PLAY

32. Learning Objective 7 What are the structures and functions of the nucleus? What are the structures and functions of the nucleus?

33. The Nucleus Control center of cell Control center of cell genetic information coded in DNA genetic information coded in DNA Nuclear envelope Nuclear envelope double membrane double membrane Nuclear pores Nuclear pores communicate with cytoplasm communicate with cytoplasm

34. Nuclear Structures Chromatin Chromatin DNA and protein DNA and protein Chromosomes Chromosomes DNA condensed for cell division DNA condensed for cell division Nucleolus Nucleolus ribosomal RNA synthesis ribosomal RNA synthesis ribosome assembly ribosome assembly

35. The Nucleus

36. Learning Objective 8 What are the structural and functional differences between smooth ER and rough ER? What are the structural and functional differences between smooth ER and rough ER?

37. Endoplasmic Reticulum (ER) Network of folded membranes Network of folded membranes in cytosol in cytosol Smooth ER Smooth ER lipid synthesis lipid synthesis calcium ion storage calcium ion storage detoxifying enzymes detoxifying enzymes Rough ER Rough ER ribosomes on outer surface ribosomes on outer surface assembles proteins assembles proteins

38. ER

39. Learning Objective 9 Trace the path of protein synthesis: Trace the path of protein synthesis: synthesis in the rough ER synthesis in the rough ER processing, modification, and sorting by the Golgi complex processing, modification, and sorting by the Golgi complex transportation to specific destinations transportation to specific destinations

40. The Golgi Complex Processes proteins synthesized by ER Processes proteins synthesized by ER Manufactures lysosomes Manufactures lysosomes Cisternae Cisternae stacks of flattened membranous sacs stacks of flattened membranous sacs

41. Transport Vesicles Formed by membrane budding Formed by membrane budding Move glycoproteins Move glycoproteins from ER to cis face of Golgi complex from ER to cis face of Golgi complex Carry modified proteins from trans face to specific destination Carry modified proteins from trans face to specific destination

42. Protein Synthesis

43. Fig. 4-14, p. 92 trans face Plasma membrane Glycoprotein Rough ER Ribosomes Polypeptides synthesized on ribosomes are inserted into ER lumen. Sugars are added, forming glycoproteins. Transport vesicles deliver glycoproteins to cis face of Golgi. Glycoproteins modified further in Golgi. Glycoproteins move to trans face where they are packaged in transport vesicles. Glycoproteins transported to plasma membrane (or other organelle). Contents of transport vesicle released from cell. Golgi complex cis face

44. Animation: The Endomembrane System CLICK TO PLAY

45. Learning Objective 10 What are the functions of lysosomes, vacuoles, and peroxisomes? What are the functions of lysosomes, vacuoles, and peroxisomes?

46. Other Organelles Lysosomes Lysosomes enzymes break down structures enzymes break down structures Vacuoles Vacuoles store materials in plant cells store materials in plant cells Peroxisomes Peroxisomes produce and degrade hydrogen peroxide (catalase) produce and degrade hydrogen peroxide (catalase)

47. Learning Objective 11 Compare the functions of mitochondria and chloroplasts Compare the functions of mitochondria and chloroplasts How is ATP synthesized by each of these organelles? How is ATP synthesized by each of these organelles?

48. Mitochondria Site of aerobic respiration Site of aerobic respiration Double membrane Double membrane inner membrane folded (cristae) inner membrane folded (cristae) matrix (cristae and inner compartment) matrix (cristae and inner compartment) Important in apoptosis Important in apoptosis programmed cell death programmed cell death

49. Mitochondria

50. Aerobic Respiration Breaks down nutrients using oxygen Breaks down nutrients using oxygen Energy from nutrients packaged in ATP Energy from nutrients packaged in ATP CO 2, H 2 O produced as by-products CO 2, H 2 O produced as by-products

51. Plastids Plastids Plastids organelles that produce and store food organelles that produce and store food in cells of plants and algae in cells of plants and algae Chloroplasts Chloroplasts plastids that carry out photosynthesis plastids that carry out photosynthesis

52. Chloroplast Structure Stroma Stroma fluid-filled space enclosed by inner membrane of chloroplast fluid-filled space enclosed by inner membrane of chloroplast Grana Grana stacks of membranous sacs (thylakoids) stacks of membranous sacs (thylakoids) suspended in stroma suspended in stroma

53. Chloroplasts

54. Photosynthesis Chlorophyll Chlorophyll green pigment in thylakoid membranes green pigment in thylakoid membranes traps light energy traps light energy Light energy converted to chemical energy in ATP Light energy converted to chemical energy in ATP used to synthesize carbohydrates from carbon dioxide and water used to synthesize carbohydrates from carbon dioxide and water

55. Mitochondria and Chloroplasts

56. Learning Objective 12 What are the structures and functions of the cytoskeleton? What are the structures and functions of the cytoskeleton?

57. The Cytoskeleton Microtubules Microtubules hollow tubulin cylinders hollow tubulin cylinders MTOCs and MAPs MTOCs and MAPs Microfilaments Microfilaments actin filaments actin filaments important in cell movement important in cell movement Intermediate filaments Intermediate filaments strengthen cytoskeleton strengthen cytoskeleton stabilize cell shape stabilize cell shape

58. Microtubules

59. Fig. 4-22b, p. 98

60. Intermediate Filaments

61. Microfilaments

62. Fig. 4-26b, p. 101 (b) Many bundles of microfilaments (green) are evident in this fluorescent LM of fibroblasts, cells found in connective tissue. 100 μm

63. Cytoskeleton

64. Animation: Cytoskeletal Components CLICK TO PLAY

65. Centrosome Main MTOC of animal cells Main MTOC of animal cells Usually contains two centrioles Usually contains two centrioles Each centriole has 9 x 3 arrangement of microtubules Each centriole has 9 x 3 arrangement of microtubules

66. Centrioles

67. Animation: Motor Proteins CLICK TO PLAY

68. Learning Objective 13 How do cilia and flagella differ in structure and function? How do cilia and flagella differ in structure and function?

69. Cilia and Flagella Cilia and flagella Cilia and flagella thin, movable structures thin, movable structures project from cell surface project from cell surface function in movement function in movement Cilia are short, flagella are long Cilia are short, flagella are long

70. Animation: Flagella Structure CLICK TO PLAY

71. Cilia

72. Fig. 4-25, p. 100

73. Learning Objective14 Describe the glycocalyx, extracellular matrix, and cell wall Describe the glycocalyx, extracellular matrix, and cell wall

74. Cell Coat Glycocalyx (cell coat) Glycocalyx (cell coat) Surrounds cell Surrounds cell Polysaccharides extend from plasma membrane Polysaccharides extend from plasma membrane

75. ECM Extracellular matrix (ECM) Extracellular matrix (ECM) Surrounds many animal cell Surrounds many animal cell Carbohydrates and protein Carbohydrates and protein Fibronectins Fibronectins glycoproteins of ECM glycoproteins of ECM bind to integrins bind to integrins Integrins Integrins receptor proteins in plasma membrane receptor proteins in plasma membrane

76. ECM

77. Cell Wall Cellulose & other polysaccharides Cellulose & other polysaccharides form rigid cell walls form rigid cell walls in bacteria, fungi, and plant cells in bacteria, fungi, and plant cells