1. And Molecular Movement Across Them
Biological Membranes
And Molecular Movement Across Them

2. Structure and Composition of Membranes

5. Membrane Lipids

7. Amphipathic
hydrophobic tails

12. Decrease Fluidity by: Increase Cholesterol Increase Length of FA Tails
Increase FA saturation

14. Decrease Fluidity by: Increase Cholesterol Increase Length of FA Tails
Lipid Raft
Fluid membrane area
Lipid raft (ridged membrane area)
Transmembrane glycoprotein
Transmembrane protein
Carbohydrate
Lipid-linked (GPI) protein
Cholesterol
Glycolipid
Decrease Fluidity by:
Increase Cholesterol
Increase Length of FA Tails
Increase FA saturation

15. Phosphatidylserine (PS) Phosphatidylethanolamine (PE)
GOLGI LUMEN
Phosphatidylserine (PS)
Phosphatidylethanolamine (PE)
Phosphatidylinositol (PI)
CYTOSOL

16. Unless flippase(s) is/are at work, the original orientation of the bilayer established in the ER is maintained

17. Membrane Asymmetry Phosphatidylcholine (PC) Sphingomyelin (SM)
Carbohydrate (glycolipid)
Phosphatidylserine (PS)
Phosphatidylethanolamine (PE)
Phosphatidylinositol (PI)
Membrane Asymmetry

18. Membrane Proteins

20. Integral
Peripheral
NaCl, , H+ , OH-

21. = Transmembrane protein Lipid-linked protein
Monolayer associated protein =
Integral Membrane Proteins

22. Cell Cortex
Cytoplasm
Extracellular Space

23. Fluorescence Recovery After Photobleaching
apical
basolateral

24. Membrane Carbohydrates

26. Molecular Movement Across Membranes

29. CARRIER
Both are SPECIFIC
Both are SATURABLE
Carriers move solutes more slowly than channels

30. facilitated diffusion
Against
With
facilitated diffusion
No Energy Required

32. With Electrical Gradient
Against Electrical Gradient

33. Active Transport

34. Outside
Inside

35. Na+-K+ ATPase

37. Co-Transport

38. Na+-Glucose Symporter
Against
With
chemical

39. Transport Through Channels
Passive Transport

41. Gated Ion Channels

46. Movement of ions across a cell membrane sets up a “voltage” across that membrane (Vm).
The Vm is the membrane potential
The Vm is measured in millivolts (mV)
The Vm of a typical resting cell is ~70mV
The Vm can change if ion channels open or close
“Excitable cells” (e.g., muscle cells, neurons) are ‘excited’ when their Vm changes rapidly.
The Vm of a resting cell can be calculated if you know ion concentrations and you make some assumptions.

48. The Vm of a typical resting cell is ~70mV

50. V = 62z log10 (Co /Ci)

51. “Electrical” Signal Transmission
Synaptic Cleft/Synapse

52. -70

53. Na+ in
DEpolarize
REpolarize
K+ out
-70
HYPERpolarize

54. Na+ in