2. Compartmentalize

3. Used by organelle membranes as well

4. Made of lipids, a major constituent

5. Not formed by linear polymerization of a smaller lipid monomer

6. Used for energy storage

7. Important for membrane structure

8. Can be used as signaling molecules

9. Provide ability for fluidity of the membrane

10. Allows for expansion

11. Not just fats and oils

12. Types of Lipids

13. Fatty acids

14. Hydrophilic and hydrophobic end

15. Hydrophilic is the COOH end

16. 16-18 carbons on average (12-20 range) is the average length of the carbon chain

17. saturated FA is CnH2nO2

18. Phospholipids

19. Membrane structure

20. 2 classes of PL

21. phosphoglycerides

22. glycerol + Pi + R group + hydrocarbon chains

23. sphingolipids

24. amino group + hydrocarbon chain + R + O

25. Serine, ethanolamine, choline, inositol can be broken down or be used for signaling or both

26. Triglycerides

27. Have fatty acids in them

28. A glycerol molecule through dehydration/condensation is linked to three fatty acids

29. Energy storage and insulation

30. Solid fats are saturated,

31. Margarine made from unsaturated fatty acids and hydrogenating it

32. Oils, unsaturated fatty acids

33. Glycolipids

34. Sugar group attacted to glycolipid molecule

35. Glycosphingolipid

36. Glycosphingosine

37. R groups with 1 to 6 monosaccharide units

38. Terpenes

39. Carotenoid

40. Plastoquinone

41. Vitamin a

42. Coenzyme Q

43. Steroids

44. Cholesterol

45. Most common in animal cells found in the PL bilayer

46. Amphipathic

47. Hydrophilic end is facing out or inside of cell, not in between

48. Important in regulating lipid fluidity

49. Terpenes

50. Bilayers form Spontaneously

51. Favorable for cell to have membrane form a spherical shape

52. Injury?

53. Phospholipids inserted to repair tear

54. If can’t be repaired by insertion, round in on itself instead

55. Lipid Bilayer

56. Import and export of molecules

57. Signaling/activation by extracellular ques

58. Motility

59. Made of phospholipids with embedded fatty acids/cholesterol/and proteins

60. Boundary for things

61. If cholesterol is embedded, space reduced between fatty acids and restricts what moves in and out, such as ions

62. Organization and localization of function of organelles

63. Allow for regulated transport processes

64. Membrane allows to bind to EXC factors because of proteins in the membrane

65. GFs

66. Cell-Cell communication

67. Signaling molecules interact by EXC contact, and activate signaling on either side

68. Gap junctions

69. Proteins that allow direct communication between cells so cytoplasm of two cells are like one

70. Fluid Mosaic Model

71. PL Bilayer is fluid and not rigid

72. Using FRAP (Fluorescence Recovery After Photobleaching), how fluid is the membrane

73. Label the cell surface with fluorescent dyes

74. Took laser and bleached spot on membrane

75. Looked over time how quickly fluorescent molecules repopulated bleached area

76. There is PL motility

77. Mechanisms of movement

78. Rotation

79. Lateral movement

80. Move by diffusion, so no energy is needed

81. Flipases

82. Enzymes that drive the flipping of PLs

83. PL Bilayer

84. The EXC and cytosolic side are different

85. Immune system responds to certain things on the outside of the cell

86. When PL are exposed that are normally on the cytosolic side, immune cells phagocytose b/c it’s a signal of a dead or dying cell

87. Membrane Fluidity

88. Tm is the temp at which membrane transitions from gel to fluid

89. Lets say 28 degress C

90. If past, more fluid

91. If lower, more solid

92. What changes Tm is strength of van der wall interactions of fatty acids in PL bilayer

93. The more linear, the stronger the van der walls forces and the higher the Tm

94. More carbons increases Tm

95. Steroids/Sterols

96. In the PM affect fluidity

97. As place in PL bilayer, there is an equal amount in both layers of the bilayer

98. Cholesterol stabilizes membrane

99. Hydroxyl groups forms H bond with carboxyl group

100. Decrease fluidity

101. Holds structure better

102. Phytosterol is in plants instead of cholesterol

103. Different Lipids in the Membrane

104. Study them by using Thin Layer Chromatography

105. Separate lipids based on polarity

106. Lipid Distribution

107. Phosphatidyl ethanolamine and serine are in the cytosol

108. Negatively charged and point to cytosol

109. Choline and spingomyelin are on the EXC side

110. Have sugar moieties resulting in EXC love

111. Lipid Raft

112. Concentrated area of PL and cholestoerl and protein embedded in membrane brought together in rigid structure.

113. More cholesterol and more saturated fatty acid tails so interaction is very tight

114. With embedded proteins, forms solid structure that moves as a unit

115. Signaling molecules are all held together

116. Glycolipids attract signaling molecules in the cell, lectins

117. Often signaling receptors on EXC

118. Results in an intracellular change

119. Help localize the functional embedded proteis to signaling molecules in the cells.