After the initial transcription process is complete, the transcript must be processed before being translated into a completed protein. RNA splicing occurs at this stage where exons are cut from the introns and put together to form the processed mRNA. The mRNA is then read by the Ribosome unit and a polypeptide chain is assembled during polypeptide synthesis. The order of the peptides or amino acids determines the shape and function of the resulting protein. Both Sulfur bonding and hydrogen bonding or hydrophilic/hydrophobic properties of the polypeptide chain cause the protein to begin to fold into a particular form as alpha sheets and beta helixes are spontaneously formed due to bonding interactions. Later stages of protein folding are assisted by protein folding complexes known as chaperones. In most cases, folded “proteins” or more accurately polypeptide units are combine to create functioning protein complexes.