Which of the following sequences of events correctly describes the progress of a protein that will be secreted from the cell?(A)
SRP binds to the growing polypeptide chain and to the ribosome.(B) Translation resumes.(C) SRP binds to its receptor.(D) The signal sequence is cleaved.(E) Protein synthesis begins in the cytosol.(F) Translation pauses.•E → A → F → C → B → D•E → F → A → C → B → D•C → F → A → B → D → E
After the export of mRNA from the nucleus, translation (protein synthesis) begins in the cytosol. Proteins that should be secreted from the cell, must e targeted to the endoplasmic reticulum (ER) and this process occurs co-translational (while translation is still in progress).The signal recognition particle (SRP) is involved in the process of targeting, because it recognizes specific signal sequences in proteins and targets that protein to the endoplasmic reticulum (SRP binds to its receptor in the membrane of the ER).
