membrane proteins

Question 1

list the 4 functions of membrane proteins

Answer 1

transporters, anchors, receptors, enzymes

Question 2

what are the 2 types of membrane protein

Answer 2

membrane imbedded (integral) and peripheral

Question 3

what is the difference between integral and peripheral membrane proteins

Answer 3

integral proteins are permanently attached to the membrane

peripheral proteins are temporarily adhered to integral proteins/ penetrate peripheral regions of the bilayer

Question 4

what is the difference between single pass TM proteins & multi pass TM proteins

Answer 4

single pass proteins pass the membrane once, multiples proteins may pass the membrane more than once

Question 5

describe alpha helices

Answer 5

uncharged polar side chains and stable H bonds in backbone (no competing water)

Question 6

describe beta barrels

Answer 6

anti parallel beta strands, aqueous pore in the middle

hydrophobic chains on outside, hydrophilic on inside

Question 7

describe amphiphatic helices

Answer 7

associated with monolayer, hydrophobic on inside, hydrophilic on outside

Question 8

what do detergents do

Answer 8

detergents extract membrane proteins from their natural environment to an aqueous enviroment

Question 9

how do detergents work

Answer 9

they hold the lipid tails/hydrophobic regions of membrane protein inside the hydrophobic interior of micelles. they hydrophilic regions are in contact with the aqueous environment

Question 10

what is the critical micelle concentration

Answer 10

the concentration at which above, detergent monomers become micelles