Arginine (English: Arginine) is an α amino acid, is one of 20 kinds of common natural amino acids. In molecular genetics, messenger ribonucleic acid structure, CGU, CGC, CGA, CGG, AGA and AGG. Is a nucleotide base or genetic codons code when protein synthesis is arginine triad. In mammalian life, arginine is classified as a semi-essential or conditionally essential amino acid (non-essential amino acids), the body can produce on their own, but at the time of stress or illness, you may need more. Also depends on the developmental stage and health status of organisms may be. Preterm children the body can not synthesize arginine, making supplement their nutrition arginine becomes very important. Was first isolated in 1886 by the Swiss chemist Ernst arginine • Schultz extracts from lentil seedlings. Semen constitutes 80% by arginine, so called arginine. Arginine can ingest any food containing protein from the such as meat, poultry, cheese products, fish and so on. The food contains a lot of arginine include chocolate, peanuts, walnuts, bananas, eggs and sesame seeds. Arginine can be counted as a double of amino acids, which is due to the main chain is the closest part of the longer side chains, organic and hydrophobic, while the other end of the side chain is a guanidine. The acidity coefficient (pKa value) guanidine was 12.48, in neutral, acidic or alkaline environment are positively charged lightning's. Because of its double bonds in the conjugated system and nitrogen isolation between the electron pair, such that it is positively charged lightning dislodged. The guanidine can form multiple hydrogen bonds.