Protein digestion will occur mainly in the upper part of the small intestine, where the duondenum and the jejunum are found, which are essential structures for the digestion of these molecules. In these structures, proteins will suffer the action of 4 enzymes produced by the pancreas. These enzymes are primarily responsible for the complete digestion of proteins. The enzymes are called trypsin, chymotrypsin, elastase and carboxypolipeptidase, they will break down proteins into amino acids that will be transported to the liver, or eliminated in the stool.