Amino acids are a group of organic compounds containing amino and carboxyl groups. First of all, it is the basic building block of macromolecule proteins and the basic substance of animal proteins. It refers to organic compounds containing basic amino and acidic carboxyl groups. Amino acids are proteins as the first nutrient elements of the body. Their nutritional role in food is very important and obvious, but they can not be directly used by the human body. They will become small amino molecules of nutrients and then be used. After a variety of digestive enzymes in the gastrointestinal tract, the high molecular protein is decomposed into low molecular amino acids or polypeptides, which are absorbed through the small intestine, and then along the portal vein into the liver, as life activities must be absorbed and used, it mainly plays four roles: First, nitrogen balance, amino acids are made up of amino and carboxyl groups, and amino is nitrogenous, so you get the right amount of nitrogen to maintain your total nitrogen balance. Second, amino acids can be converted to fat, and the alpha ketoacids produced by amino acid catabolism are metabolized along metabolic pathways, either to form new amino acids or to be converted to sugars or fats, stored in the body, and then, through a series of cycles, broken down into carbon dioxide and water, and released simultaneously. Third, amino acids produce carbon units, including methyl and methylene groups, which are the raw materials for the synthesis of purines and pyrimidines. Fourth, it is involved in the formation of enzymes, which can form some enzymes, hormones and part of vitamins, which can play a role in regulating physiological effects and catalyzing physiological metabolism, which is a very key performance.