How do integral membrane proteins enter the lipid bilayer?
A)They insert into the membrane from the RER lumen after their synthesis is complete.
B)The aqueous translocon channel has a gate that continuously opens and closes, giving each nascent polypeptide segment a chance to partition itself into the lipid bilayer's hydrophobic core.
C)They insert into the membrane from the cytosol after their synthesis is complete.
D)The membrane is disrupted and proteins are incorporated during reassembly.

Question

Quizplus · Accepted Answer

Integral membrane proteins enter the lipid bilayer through the aqueous translocon channel by partitioning themselves into the lipid bilayer's hydrophobic core. The translocon channel has a gate that continuously opens and closes, allowing the nascent polypeptide segments to insert themselves into the bilayer. Option A is incorrect because integral membrane proteins do not insert into the membrane from the RER lumen after their synthesis. Option C is incorrect because integral membrane proteins are not inserted into the membrane from the cytosol after their synthesis. Option D is incorrect because the membrane is never disrupted for protein incorporation during re-assembly.

How Do Integral Membrane Proteins Enter the Lipid Bilayer