Cell membrane structure Flashcards
what is a phospholipid made of
one phosphate
one glycerol molecule
2 fatty acids
what are the properties of a phospholipid (head and tail)
phosphate head:
hydrophilic
touches water on outside of bilayer
polar
fatty acid tail:
hydrophobic
does not touch water
on the inside of the bilayer
non polar
what is the cell membrane made of
2 layer phospholipid
what are the properties of a cell membrane
semi permeable
allow substances in and out of cell
break and fuse back together
flexible
fluid
what is found on the outside of the cell membrane
glycoproteins
glycolipids
what is the roll of glycolipids on the outside of the cell membrane
stabilise the cell membrane
surface receptors
what is the roll of glycoproteins on the outside of the cell membrane
cellular recognition (hormones + neurotransmitters)
stabilise cell membrane structure
what is found on the inside of a cell membrane
protein
cholesterol
channel protein
what are transmembrane proteins and where are there hydrophobic and hydrophilic ends
proteins embedded in bilayer
span membrane (intrinsic and integral proteins)
hydrophobic part of protein is inside bilayer
hydrophilic part of protein is on the outside of bilayer (surface)
what is the roll of channel proteins on the inside of the cell membrane
control what substances enter and leave of the cell
spans whole bilayer
what is the roll of cholesterol on the inside of the cell membrane
regulates fluidity
prevents fatty acid tails packing closely together (sway like seaweed)
stabilises membrane
what are the features of an intrinsic protein
intrinsic-
full embedded into the membrane
span the membrane
act as channels or carrier proteins to transport water soluble molecules
what are the features of an extrinsic protein
extrinsic-
partially spans membrane
attached to either inside or outside of phospholipid layer
not embedded in plasma membrane
what is a monolayer, bilayer and micelle
monolayer- chain of phospholipids in air
bilayer- 2 phospholipid layers with hydrophobic tails facing towards each other away from water and hydrophilic heads facing the outside toward water
micelle- in water phospholipids arrange in a circle with heads facing out and tail in
what is a glycoprotein made of
protein with carbohydrates attached to
