Final answer:
The signal recognition particle (SRP) is responsible for directing proteins to the ER for secretion.
Step-by-step explanation:
The (SRP) signal recognition particle is responsible for directing proteins to the ER for secretion.
Once a protein's first few amino acids have been translated, the SRP binds to a tag called a signal sequence on the protein. This binding stops translation and allows the mRNA-ribosome complex to be shuttled to the endoplasmic reticulum (ER). Once the complex reaches the ER, the SRP is removed and translation resumes.
Overall, the SRP plays a crucial role in ensuring that proteins are correctly directed and transferred to the ER for further processing and secretion.