Molecular chaperones play a critical role in protein folding, ensuring that newly synthesized proteins acquire their proper tertiary structure. These chaperones assist in preventing the misfolding or aggregation of proteins, a process that can lead to diseases such as Alzheimer's or cystic fibrosis. By binding to nascent polypeptides, molecular chaperones provide an environment conducive to correct folding and allow for the proper assembly of multi-subunit complexes. They facilitate the protein's functionality and stability, highlighting their essential role in cellular homeostasis.