Final answer:
Chaperones and structural modifications ensure the proper folding of proteins in the ER before exportation.
Step-by-step explanation:
The proper folding of proteins in the endoplasmic reticulum (ER) is ensured through the involvement of chaperones and structural modifications.
Chaperones are helper molecules that assist proteins in attaining their correct conformation. They prevent proteins from forming incorrect structures by providing a favorable environment for the folding process. Chaperones can also prevent premature folding by binding to proteins before they are fully synthesized.
In addition, proteins undergo structural modifications, such as the acquisition of side chains, in the ER. These modifications are important for ensuring proper protein folding, stability, and functionality before they are exported to their final destinations.