Question

How are integral membrane proteins thought to enter the lipid bilayer?

1) They insert into the membrane from the cytosol after their synthesis is complete
2) They insert into the membrane from the RER lumen after their synthesis is complete
3) The translocon channel appears to have a gate that gives the polypeptide segment a chance to move into the lipid bilayer's hydrophobic core
4) It is thought that they burrow into the lipid bilayer
5) It is thought that they are enzymatically implanted in the lipid bilayer

Answer 1

Integral membrane proteins enter the lipid bilayer by inserting through the translocon channel, which provides a gate for the polypeptide segment to move into the hydrophobic core of the bilayer.

Step-by-step explanation:

Integral membrane proteins enter the lipid bilayer through a process called insertion. This process involves the translocon channel, which acts as a gate to allow the polypeptide segment of the protein to move into the hydrophobic core of the lipid bilayer. It is thought that the hydrophobic domains of the protein anchor it in the membrane while the hydrophilic domains interact with molecules inside or outside the cell.