Membrane stuff from Agbas, some of it is under the glycosylation deck

Question 1

Integral proteins

Answer 1

Contain extensive hydrophobic regions, span the full length of the membrane, have two hydrophobic ends

can be removed with soaps and detergents

Question 2

Peripheral proteins

Answer 2

Do not span length of membrane

Attached primarily through electrostatic and hydrogen bonds, also can covalently attach themselves to the fatty acid chains in the bilayer interior

can be removed with salts or a pH change

Question 3

alpha helices are where in the phosoplipid layer?

Answer 3

interior, usually at a perpendicular angle to the plane of the membrane

Question 4

Bacteriorhodopsin (BR)

Answer 4

integral protein, light activated, possess numerous alpha helical chains in the hydrophobic interior

Question 5

Cyclooocygenase or Prostaglandin H2 synthase (PGHS)

Answer 5

an integral protein: binds to luminal leaftet of the ER

homodimer consisting of primarily alpha helices

does not span the membrane!!!!!!!!!!!

Question 6

Palmitoylation

Answer 6

when a link between occurs between cystein’s sulfur group and the carbonyl group on a lipid (such as a fatty acid): called a thiol-ester bond