Protein, whose smallest component molecules are amino acids, accounts for the second largest proportion of human body next to water. Amino acids connect with each other by peptide bond and are the component material of protein.
The main amino acids wanted by human body are about twenty kinds. (There must be enough kinds and quantities of amino acids to synthesize specific protein inside human body, or synthetic reaction wouldn’t happen.) Whether the twenty amino acids line up and combine with each other smoothly inside human body or not affects human structure and physical activities. Arginine is a kind of important amino acid required by human body and is a vital element determining human’s disease or health, youth or aging.