1. Cellular Level of Organization

2. Introduction Two types of cells Sex cells (haploid)
Somatic cells (diploid)

4. Cell Membranes
4 main functions

5. 1. Physcial Isolation
Separates inside of cell from outside

6. 2. Selectively Permeable Membrane
Regulates exchange with the environment

7. 3. Sensitivity
Contains receptors

8. 4. Structural Support
The cell membrane can connect to other cells or extracellular proteins

9. Cell Membrane Structure
Hydrophilic head
Hydrophobic tails

11. Cell Membrane Structure
Ions and water soluble compounds cannot cross the membrane

12. Cell Membrane Structure
This separates the extracellular fluid from the cytosol which is important for homeostasis

13. What are in membranes?
1. Cholesterol

15. What are in membranes?
Integral proteins

17. What are in membranes?
Enzymes
Catalyzes reactions

18. What are in membranes?
Receptor proteins
Protein – lock
Ligand - key

19. What are in membranes? 5. Carrier Protein
Transports things across the membrane

20. What are in membranes? Channels
Allows continuous movements of ions and water soluble materials

21. What are outside cell membranes?
Peripheral proteins
Glycoproteins
Glycolipids

23. Glycoprotiens and glycolipids
Can tell if certain cells are normal or abnormal by their glycoproteins and glycolipids

24. Organelles
Components of cells

25. 1. Cytoskeleton Strength and flexibility Composed of 3 main structures
Microfilaments ( actin )
Intermediate filaments ( collagen )
Microtubules ( tubulin )

27. 2. Microvilli Increase surface area
Finger-shaped projections of cell membranes

28. 3. Centrioles Their involved in cell division
Not found in RBC, skel. muscle cells, cardiac muscle cells, and neuron cells

30. 4. Cilia
Long slim extensions of the cell membrane
Found in trachea

31. 5. Ribosomes Synthesize proteins
Composed of two subunits ( one small and one large)
Free ribosomes
Fixed ribosomes

34. 6. Endoplasmic Reticulum
Network within the cytoplasm attached to the nucleus

37. 6. Endoplasmic Reticulum
Two types
SER
RER

40. 6. Endoplasmic Reticulum
SER
Detoxifies drugs or toxins
Synthesizes lipids and carbs

41. 6. Endoplasmic Reticulum
RER
Transports materials and synthesizes proteins

42. 7. Golgi Apparatus
Proteins come from the ER into the golgi for modification

45. 8. Lysosome Breaks down and recycles organelles
Breaks down bacteria and foreign material

48. 9. Peroxisomes
Breaks down fatty acids and organic compounds

50. 10. Mitochondria Powerhouse of the cell Produces ATP – energy
Contains two membranes (outer and inner)

53. 11. Nucleus
Chromosomes are stored here
Composed of DNA

54. Membrane Transport
Membranes are selectively permeable

55. Membrane Transport
Passive processes do not require energy

56. Membrane Transport
Active processes require energy

57. Membrane Transport 3 major ways in which materials are transported
Diffusion
Carrier-mediated transport
Vesicular transport

58. Diffusion
Hypotonic solution – less concentrated

59. 1. Diffusion
Hypertonic – more concentrated

60. 1. Diffusion
Isotonic solutions – equal concentration

61. 1. Diffusion
Solutes move from hypertonic solution to hypotonic solution

62. Ions and Water
Remember ions and water must pass through channels

63. Lipid Soluble Substances
Alcohol, fatty acids, and steroids are lipid soluble

64. O2 and CO2
O2 and CO2 pass easily

65. Glucose
Glucose to big to cross cell membrane

66. 2. Carrier-Mediated Transport
Can be passive or active

67. 2. Carrier-Mediated Transport
Proteins carry substances across

68. 2. Carrier-Mediated Transport
Sometimes carries two things at once (cotransport)

69. 2. Carrier-Mediated Transport
Sometimes carries to things in opposite directions (countertrasnport)

70. 2. Carrier-Mediated Transport
Fascilitated Diffusion
Active Transport
Secondary Active Transport

71. Facilitated Diffusion
Passive

72. Facilitated Diffusion
Carries substances such as glucose and amino acids

73. Facilitated Diffusion
Goes down conc. Gradient but limited to number of carrier proteins

74. Active Transport
Requires energy

75. Active Transport
Not dependent on concentration gradient

76. Active Transport
Ion pumps use active transport

77. Active Transport
Exchange pumps move two kinds of ions in different directions
Example: Na+/K+ Pump

78. Na+/K+ Pump
Na higher in concentration outside cell
K higher in cell

79. Na+/K+ Pump
Sometimes Na diffuses into cell and K leaves through leaky channels

80. Na+/K+ Pump
Na+/K+ pump puts things back into order

81. Na+/K+ Pump
Ejects on average 3Na+ and bringing in 2K+ ions

83. Secondary Active Transport
Does not require energy

84. Secondary Active Transport
Goes down a conc. gradient

85. Secondary Active Transport
It uses the concentration gradient of a molecule as the driving force to move another molecule against the concentration gradient

86. 3. Vesicular Transport
Requires energy

87. 3. Vesicular Transport
Endocytosis
Exocytosis

88. Endocytosis
Imports substances into the cell

89. Endocytosis
Receptor mediated endocytosis
Pinocytosis
Phagocytosis

90. Receptor Mediated Endocytosis
Extremely selective

91. Receptor Mediated Endocytosis
Plasma membrane proteins bind only with certain substances

93. Pinocytosis
Cell drinking

94. Pinocytosis
Dissolved proteins gather on the external surface of the plasma membrane, causing the membrane to invaginate and to incorporate a droplet of fluid

96. Phagocytosis
Cell eating

97. Phagocytosis
Parts of the plasma membrane flow around a relatively large or solid material and engulf it.

99. Exocytosis
Expels material out of the cell