Within the cell, proteins are continuously constructed from amino acid building blocks strung together like beads on a necklace using a gene as a template for the sequence. The process of folding a protein is spontaneous and depends on the interactions of the chain with itself and surrounding water
Protein and RNA folding develops on many different timescales ranging from nanoseconds to seconds. While the longest times have been probed experimentally for many years, only in the past decade have advances in laser spectroscopy allowed a view into dynamics faster than 1 millisecond.
While the protein is folding there is always a danger of aggregating with other nearby proteins, forming disordered aggregates and fibrils. This is the basis for many diseases, such as Alzheimer's, Parkinson's and Type-II diabetes.