Polypeptides are long chains of amino acids linked together by peptide bonds. They are essential building blocks of proteins, which play crucial roles in the body, such as supporting cell structure, facilitating chemical reactions, and transporting molecules. Each polypeptide has a unique sequence of amino acids that determines its specific function and shape. When polypeptides fold into specific three-dimensional structures, they become functional proteins. The process of folding is influenced by various factors, including the surrounding environment and the presence of other molecules. Understanding polypeptides is vital in fields like biochemistry and molecular biology, as they are fundamental to life and health.