Final answer:
When the SRP binds to the signal peptide, protein synthesis slows down as the SRP-ribosome complex searches for the RER membrane. The SRP later detaches from the growing polypeptide chain, and elongation resumes with the hydrolysis of the signal peptide. This process ensures proper targeting and membrane insertion of the translated protein.
Step-by-step explanation:
When the SRP (signal recognition particle) binds to the hydrophobic signal peptide, it slows down protein synthesis. This is because the SRP-ribosome complex needs to find the RER membrane before translation elongation can resume. The SRP detaches from the growing polypeptide chain to be recycled, and translation elongation continues through a translocation channel.
A signal peptidase in the RER membrane then catalyzes the co-translational hydrolysis of the signal peptide, which remains embedded in the RER membrane. Elongation continues, and the growing polypeptide begins to fold in the RER. Overall, the binding of SRP to the signal peptide temporarily slows down protein synthesis to ensure proper targeting and membrane insertion of the translated protein.