This document discusses the composition and structure of cell membranes. It notes that membranes contain lipids like sterols and glycolipids that form lipid rafts and help attach proteins. Membranes contain different ratios of proteins to lipids depending on their origin, such as mitochondria or myelin sheaths. The document categorizes types of membrane proteins and how they can attach to or span the membrane. It also outlines techniques for extracting and analyzing membrane proteins, such as using detergents and SDS-PAGE gel electrophoresis.

2. Lipid Rafts

3. Negative charge in cytosol is important for movement of ions

4. Made of carbs and hydrocarbon chains

5. Serine-based glycolipids

6. Lectin helps hold structure and important for recruiting proteins that can be important for signaling

7. GPI – anchored proteins are importat for signaling

8. Way proteins can be attached and used for metabolic processes

9. Carb/glycolipid concentration is high

10. Can contain kinases that are held close to receptors so when bound, the kinases can respond and recognize the Pi and induce intracellular signaling

11. Concetration of embedded proteins varies depending on membrane

12. Bacterial: protein/lipid ratio = 3

13. Myelin: protein/lipid ratio = .23

14. Mitochondria: protein/lipid ratio = 1.2 for outer, inner is 3.5, for ETCs

15. Membrane Composition/Classification of Membrane Proteins

16. Transporters

17. Anchors

18. Receptors

19. PDGF

20. Enzymes

21. Transmembrane Proteins

22. Cytosolic is amino terminus normally, or multiple transmembrane spanning region

23. Monolayer Associated

24. Pores

25. Lipid-linked

26. covalent

27. Protein-attached

28. Associated with transmembrane proteins.

29. H-bonds

30. Lipid-Anchored Protein

31. Amide linakge

32. Myristal linker

33. Attaches any available protins with proper groups

34. Farnesyl anchor

35. Thio-ether linkage between cystein and prenyl group

36. Hydrophobicity Plot

37. Extracting Membrane Proteins

38. Treat with detergents

39. Denatures proteins

40. SDS or

41. Triton with negative charge

42. MAINTAINS STRUCTURE OF PROTEIN BETTER and prevents denaturization

43. Detergents forms micelle like structure

44. Detergent will interact with hydrophobic membrane spanning regions of the protein

45. Use SDS-Page – western blotting

46. Due to SDS’ negative charge, the positive charge attracts proteins and will separate based on size and according to charge

47. One stain is coomasie stain

48. Indicates stained proteins and which proteins you have based on size

49. More Biology Techniques

50. Membrane Proteins can be Glycosylated

51. N-lined glycoslyation

52. Carb group bound to amino group of asparagine

53. O-linked glycoslyation

54. OH groups of serine or threonine linked to carbohydrate