Question

Determine whether the following classes of proteins are synthesized on free ribosomes or ER docked ribosomes.

a) Single-pass membrane proteins

b) Multi-pass membrane proteins

c) Peripheral membrane proteins (on the cytosolic side)

d) Peripheral membrane proteins (on the luminal side)

e) Peripheral membrane proteins (on the extracellular side)

f) Fatty acid-anchored membrane proteins

g) GPI- anchored membrane proteins

- Where would a protein likely go if you were to remove a characteristic hydrophobic membrane spanning domain?

Answer 1

a) Single-pass membrane proteins - ER docked Ribosome
b) Multi-pass membrane proteins - ER docked Ribosome
c) Peripheral membrane proteins (on the cytosolic side) - Free Ribosome
d) Peripheral membrane proteins (on the luminal side) - ER docked Ribosome
e) Peripheral membrane proteins (on the extracellular side) - ER docked Ribosome
f) Fatty acid-anchored membrane proteins - Free Ribosome
g) GPI- anchored membrane proteins - ER docked Ribosome

It will circulate inside the cytoplasm or export outside of the cell because hydrophobic membrane spanning domain involves in plasma membrane protein like intergal membrane protein