Removal of the signal peptide from the preproinsulin molecule synthesized by the beta-cell
A) occurs in the lumen of the endoplasmic reticulum during, or shortly following, translation of the preproinsulin mRNA.
B) is inhibited by hyperglycemia.
C) occurs during packaging of the insulin molecule by the Golgi apparatus.
D) occurs in plasma.
E) none of the other answers is correct.

Question

Quizplus · Accepted Answer

The removal of the signal peptide from the preproinsulin molecule synthesized by the beta-cell occurs in the lumen of the endoplasmic reticulum during, or shortly following, translation of the preproinsulin mRNA. This process transforms the preproinsulin molecule into proinsulin, which is then further processed and packaged by the Golgi apparatus to form mature insulin. Hyperglycemia does not inhibit this process, and insulin does not get processed in plasma.

Removal of the Signal Peptide from the Preproinsulin Molecule Synthesized