The first part of a new polypeptide chain being produced in a eukaryotic cell has a signal peptide. Translation of this polypeptide ____.
A) occurs on a free ribosome in the cytosol
B) begins on a free ribosome in the cytosol and is completed on the rough ER
C) occurs in the Golgi apparatus
D) begins on the rough ER and is completed in the Golgi apparatus
E) occurs on the rough ER

Question

Quizplus · Accepted Answer

The presence of a signal peptide directs the ribosome to the rough endoplasmic reticulum (ER) where translation is completed. Translation begins on a free ribosome in the cytosol, and once the signal peptide emerges, it is recognized by a signal recognition particle that directs the ribosome to the ER.

The First Part of a New Polypeptide Chain Being Produced