cell membrane structure Flashcards
define hydrophobic
hates water
define hydrophyllic
loves water
why do phospholipids form a bilayer
form a bilayer to make sure the hydrophobic fatty acid tails stay away from water
what can pass through the phospholipid bi layer
- lipid soluble
- small uncharged molecules
(O2, CO2) - only certain things can pass through
= selectively permeable
what is the function of proteins in the phospholipid bi layer
- stability
- transport
what are the 2 types of proteins in the phospholipid bilayer
- channel proteins
- carrier proteins
what do channel proteins allow the passage of
specific ions
(each ion has it’s own specific channel protein)
e.g : Na+ channel protein is different to the Ca2+ channel protein
what do the 2 types of carrier proteins allow the passage of or the type of reaction to take place
passive process
large molecules (glucose)
specific
active process
active transport
define phospholipid
a molecule with a phosphate head and a fatty acid tail
define glycolipid
phospholipid with a carbohydrate chain attached
define glycoprotein
protein in the membrane with a carbohydrate chain attached
what is the function of glycolipids and glycoproteins
cell recognition (antigens, receptors)
tissue formation
what is the function of cholesterol in the membrane
stability and fluidity
why is the fluid mosaic model called fluid
molecules can move about within the phospholipid bi layer
why is the fluid mosaic model called mosaic
membranes made from different molecules (phospholipids, proteins)
