Proline is an Essential Amino Acid (EAA) found in many proteins. It contains an imino acid side chain, which is characterized by a ring structure in the backbone. Proline is also known for its role as a structural element of proteins, as it forms covalent bonds with the backbone and structure of proteins, helping to stabilize the tertiary structure. Other roles of proline include helping to form enzymes, being part of the energy metabolism and locomotion of cells, and helping with wound healing. Proline is also a precursor to a wide variety of bioactive compounds, such as collagen and thymidine, making it an important part of the human body.