1. A Tour of the Cell

2. Anton Van Leeuwenhoek (1600’s) Credit for the first microscope Looked at pond water and saw “wee beasties”

4. Robert Hooke Observed plant stems, wood, and cork (1600’s) Saw all the tiny chambers and called them CELLS What cell part did Hooke observe? Cell Wall

7. Robert Brown (1833) Observed that cells had a dark structure within plant cells Brown observed the nucleus and stated that all cells have nuclei (at this time no one knew that the nucleus has DNA)

8. Matthias Schleiden (1838) Stated that all plants are made of Cells Made many observations of plants around the area

9. Theodor Schwann (1839) Stated that all animals are made of Cells Observed many animal tissues

10. Rudolf Virchow (1855) Stated that all cells come from pre-existing cells Cells arise from the division of pre-existing cells

11. The Cell Theory Microscopes Provide the Windows to the World of the Cell

12. The Cell Theory All living things are composed of cells Cells are the basic unit of structure and function in living things All cells come from pre-existing cells

13. A Prokaryotic Cell

14. The Size Range of Cells

15. Cell Sizes Average Animal Cell – 15 microns Average Plant Cell – 40 microns Average Eukaryotic Cell :10-100 microns Average Prokaryotic Cell: 1-10 microns

16. An Electron Microscope

17. Geometric Relationships Explain Why Most Cells Are Microscopic

18. Overview of an Animal Cell

19. Human Cheek Cells

20. Overview of a Plant Cell

21. Onion Epithelial Cells

22. Animal Cell’s Cell Membrane

23. Cell or Plasma Membrane “Fluid Mosaic” Model Lipid Bilayer (made of phospholipids) Proteins embedded throughout Semi-permeable or Selectively Permeable

24. Cell Wall provides support to the perimeter of plant cells, some protists, and bacterial cells

25. The Plasma Membrane

26. The Nucleus and Its Envelope

27. Nuclear Envelope/Membrane Double Membrane that surrounds the nucleus Lined with pores Supported by nuclear lamina

28. Nucleolus Inside the nucleus Site of ribosome and rRNA synthesis

29. Ribosomes

30. Endoplasmic Reticulum (ER)

31. Endoplasmic Reticulum (ER) Rough ER Intercellular transport of materials, particularly proteins; site where proteins leave ribosomes and are chemically modified

32. Smooth ER breaks down toxic substances, regulates Ca levels, synthesizes steroids and other lipids

33. The Golgi Apparatus

34. Golgi Apparatus Modifies proteins and other substances from the ER for export from the cell

35. Lysosomes

36. Digest cellular waste and foreign substances Breakdown of lipids, carbohydrates, and proteins

37. The Formation and Functions of Lysosomes

38. Plasma membrane expands by fusion of vesicles; proteins are secreted from cell Transport vesicle carries proteins to plasma membrane for secretion Lysosome available for fusion with another vesicle for digestion 4 5 6 Nuclear envelope is connected to rough ER, which is also continuous with smooth ER Nucleus Rough ER Smooth ER cis Golgi trans Golgi Membranes and proteins produced by the ER flow in the form of transport vesicles to the Golgi Nuclear envelop Golgi pinches off transport Vesicles and other vesicles that give rise to lysosomes and Vacuoles 1 3 2 Plasma membrane Relationships among organelles of the endomembrane system Figure 6.16

39. Peroxisomes Contain an assortment of enzymes that perform such roles as detoxification of alcohol, breaking down of fatty acids Produces H 2 O 2 in the process

40. Peroxisomes

41. The Chloroplast, Site of Photosynthesis

42. Plastids May be called chromoplasts or leukoplasts Store starch, fat or contain pigments such as chlorophyll or carotenoids to capture energy from the sun

43. The Mitochondrion

44. Mitochondrion Site of cellular respiration and synthesis of ATP, a source of chemical energy for the cell

45. The Plant Cell Vacuole

46. Vacuoles Store water, salts, proteins, carbohydrates, or enzymes

47. The Cytoskeleton

48. Cytoskeleton Protein strands that give the cell its shape and size Helps organize the location of organelles and their activities

49. There are three main types of fibers the make up the cytoskeleton: 1) Microtubules 2) Microfilaments 3) Intermediate Filaments

50. Microtubules Are made of the protein tubulin Shape and support the cell Are responsible for the separation of chromosomes during cell division

51. Centrosome Containing a Pair of Centrioles

52. Centrioles Appear during mitosis in animal cells; are composed of nine sets of triplet microtubules in a ring Centrosome Area from which the centrioles radiate during mitosis

53. Ultrastructure of a Cilium or flagellum

54. Cilia and Flagella In eukaryotes, a specialized arrangement (“9 + 2”) of microtubules is responsible for the beating of flagella and cilia The protein, dynein, is responsible for the movement

55. How Dynein “Walking Moves Cilia and Flagella

56. A Comparison of the Beating of Flagella and Cilia

57. The microtubule assembly of a cilium or flagellum is anchored in the cell by a Basal Body, which is structurally identical to a centriole.

58. Sea Urchin Sperm

59. Microfilaments and Motility

60. Microfilaments also aid in Cell motility (Ex: pseudopodia) Cell division (cleavage furrow formation) Cytoplasmic Streaming

61. A Structural Role of Microfilaments

62. Microfilaments Made of the protein actin Located in the cytoplasm of most eukaryotic cells Works with myosin to cause muscle cell contractions

63. Intermediate Filaments Anchor nucleus and other organelles Reinforces cell shape Make up nuclear lamina that lines the interior of the nuclear envelope

64. Plant Cell Walls

65. Intercellular Junctions in Animal Tissues

66. Extracellular matrix (ECM)

67. 1)What are the two major types of electron microscopes? 2) All cells are classified as either _______ or _____.

68. 3) Under the microscope, bacteria are typically measured in ___________ (units). 4) Two similarities between plant and animal cells are.... two differences are....

69. 5) The term used to describe the fact that the cell membrane allows some materials in and keeps others out is... 6) The lipid bilayer of the cell membrane is made of:

70. 1)The organelle that packages proteins for export from the cell is the... 2) Cellular respiration occurs in the ___________ and energy is made in the form of ________.

71. 3) The major difference between a prokaryotic and eukaryotic cell is that a prokaryotic cell lacks a/an: 4) The oldest cells on earth are ______ cells. They evolved.... years ago.

72. What characteristic of the cell membrane allows some molecules into the cell and keeps other out? The primary purpose of the cell wall is..

73. The cell membrane is composed primarily of.. Why is the cell membrane referred to as a “fluid mosaic model”? Since some molecules can pass through the cell membrane and others cannot it is termed..

74. If a molecule is too big to get through the cell membrane, it must enter through _________ channels. The centers of protein synthesis in the cell are the _________.

75. Describe the role of the cytoskeleton in the cell. Name two different things stored by vacuoles.