Question

In the process of translocating a polypeptide across the membrane of the endoplasmic reticulum, a stop transfer sequence halts the process. What eventually becomes of the stop transfer sequence?

Answer 1

Alpha-helical membrane spanning  segments

Explanation:

• In single-pass trans membrane proteins, the polypeptide crosses just a single time, while in multi pass trans membrane proteins, the polypeptide chain crosses on different occasions. An elective path for the peptide bonds in the lipid bilayer to fulfill their hydrogen-holding prerequisites is for different trans membrane strands of polypeptide chain to be orchestrated as a β sheet as a shut barrel  This type of multi pass trans membrane structure is seen in proteins, which we examine later. The solid drive to augment hydrogen holding without water likewise implies that a polypeptide chain that enters the bilayer is probably going to go completely through it before altering course, since chain bowing requires lost ordinary hydrogen-holding communications.  
• Since trans membrane proteins are famously hard to take shape, generally few have been examined completely by x-beam crystallography. The collapsed three-dimensional structures of practically the entirety of the others are dubious. DNA cloning and sequencing strategies, in any case, have uncovered the amino corrosive successions of enormous quantities of trans membrane proteins, and it is frequently conceivable to foresee from an investigation of the protein's arrangement which parts of the polypeptide chain reach out over the lipid bilayer.