Chapter 11: Membrane Structure Flashcards
Membrane Composition
lipids and proteins
Integral proteins
directly attached to membrane
Peripheral
loosely associated with membrane
The rearrangement of the phospholipid bilayer favors what?
- repair of damage
- formation of a closed compartment ( which is more favorable)
Liposomes structure
phospholipid bilayer and aqueous interior
How can phospholipids move?
- lateral diffusion
-flexion
-rotation
-flip-floping sides ( rarely occurs)
Phospholipid affect on membrane fluidity
-fatty acid chain length (shorter = more fluid)
-fatty acid
chain saturation (cis double bond = more fluid)
Sterol affect on membrane fluidity
Cholesterol ( high concentration more fluid)
- if most fatty acids are unsaturated then cholesterol creates less fluidity
Temperature affect on membrane fluidity
high temp ( high fluidity)
low temp ( more rigid)
is cholesterol amphipathic
yes
What is the pattern of mature membranes
asymmetrical
1st step of membrane synthesis
in the smooth ER phospholipids are added no the cytosolic face
2nd Step of membrane synthesis
scramblases randomly flip phospholipids from one face of the membrane to the other in the ER
3rd Step of membrane synthesis
Flippases move specific phospholipids from the extracellular face to the cytosolic face in the Golgi. Floppases move phospholipids from the cytosolic face to the extracellular face of the Golgi
Where do glycolipids obtain their sugar?
inside the Golgi