Proteins are the product of a gene that are formed from translation of a mature mRNA molecule. Proteins contain 4 elements in regards to their structure: primary, secondary, tertiary and quaternary. The linear amino acid sequence is also known as the primary structure. Hydrogen bonding between the amino acids of the primary structure results in the formation of alpha helices or beta sheets. These stable foldings are the secondary structure. The particular combination of the primary and secondary structures form the tertiary structure of a polypeptide. The quaternary structure refers to the way multiple chains of polypeptides fold together.