Lymphedema (lymphoedema in British English), also known as lymphatic obstruction, is a condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system, which normally returns interstitial fluid to the thoracic duct and then the bloodstream.ymphedema (lymphoedema in British English), also known as lymphatic obstruction, is a condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system, which normally returns interstitial fluid to the thoracic duct and then the bloodstream.
1 A polypeptide is a single linear chain of many amino acids, held together by amide bonds. 2  A protein is one or more polypeptide (more than about 50 amino acids long).  An oligopeptide consists of only a few amino acids (between two and twenty).
Proteins are composed of Î±-amino acids linked together by peptide bonds into polypeptide chains. An amino acid is characterized by an amino group (-NH2) and a carboxylic acid group (-COOH) linked to a carbon, known as the Î±-carbon.Also attached to the Î±-carbon is a H and various R-groups or side-chains.he peptide bond has a number of characteristics that are critical in determining how polypeptides behave. Although drawn as a single bond, the peptide bond behaves more like a double bond. While there is free rotation around a single bond, rotation around a peptide bond is constrained.