Biological membranes Flashcards
what is sarcoplasmic reticulum
inner membrane of mussel cells (like clam)
describe the lipid bilayer
- trilaminar
- made up of phospholipids
- proteins are embedded in the phospholipid bilayer
- head is hydrophilic (love water)
- Tails are hydrophobic (hate water)
describe how proteins are embedded in the bilayer and their movement
- they are diffused within the bilayer
- movement is restricted
- long range diffusion is slow
- biological modification can alter protein mobility in the membrane
define amphipathic
having both hydrophobic (non-polar) and hydrophilic (polar) regions
what are the characteristics all membranes share
they are the same size
stable
flexible
capable of self assembly
the inner membranes of ______ contains a very high concentration of protein
the inner membrane of mitochondria contains a very high concentration of protein
what is a myelin sheath
the myelin sheath consists of layers of plasma membrane, forming insulation around the nerve axons (a modified plasma membrane structure)
what are the three classes of plasma membrane proteins
integral
lipid-anchored
peripheral
describe integral membrane proteins
they span the lipid bilayer
describe lipid-anchored proteins
protein attached to a lipid in the bilayer
describe peripheral
associated with surfaces of the lipid bilayer
in many plasma membranes, the outer layer contains ______ and _______
glycolipids and glycoproteins
what are glycolipids and glycoproteins
lipids and proteins with carbohydrate attached
cells with different functions have ?
cells with different function have membranes with different protein compositions
integral proteins have?
integral proteins have hydrophobic transmembrane domains that are embedded in membranes
