There are about 20 kinds of amino acids in human proteins, which can be divided into non-polar hydrophobic amino acids such as isoleucine, polar neutral amino acids such as glutamine, aromatic amino acids such as tyrosine, acidic amino acids such as aspartic acid, and alkaline amino acids such as lysine, according to the structure of the side chain and the physicochemical properties. 1. Non-polar hydrophobic amino acids: glycine, alanine, valine, leucine, isoleucine, proline, methionine. 2. Polar neutral amino acids: serine, cysteine, asparagine, glutamine, threonine. 3. Aromatic amino acids: phenylalanine, tyrosine, tryptophan. 4. Acidic amino acids: aspartic acid, glutamic acid. 5. Alkaline amino acids: arginine, lysine, histidine. In the daily diet, pay attention to supplement the amino acids needed by the human body, to avoid inducing related diseases due to deficiency.