membranes and membrane transport Flashcards
lipid is bilayer is …. + ….. …..
dynamic
selectively permeable
what do the proteins in the lipid bilayer enable
signalling, communication + selective permeability
what are the cell membranes a mix of
glycolipids
phospholipids
sphingolipids
cholesterol
what are phospholipids made from
glycerol
phosphate
head group
hydrocarbon tail
phospholipids are ……….
amphipathic
why are phospholipids amphipathic
hydrophilic head = face towards fluid
hydrophobic tail = face each other
where do the hydrophobic tails face
towards each other
where do the hydrophilic heads face
towards fluid
what are the tails described as
hydrophilic
what are the heads described as
hydrophobic
what determines the fluidity of the membrane
fatty acid chains
what do fatty acid chains determine
the fluidity of the membrane
what are phosphoglycerides derived from
glycerol
what are sphingolipids derived from
sphingosine
what is functionally important
lipid symmetry
describe glycolipids
found in the non cytosolic layer only
contain sugar
made from sphingosine
glycosylation occurs in lumen of golgi
what do the inner and outer monolayers have
different compositions
describe cholesterol
modulates the properties of lipid bilayers
inserts between membrane phospholipids
tightens packing in bilayer
decreases membrane permeability to small molecules
increases rigidity
different cells have different lipid compositions
what does the hydrophobic nature of fatty acids derive
the structure formed by phospholipids
what do lipid bilayers spontaneously do
close to form sealed compartments