| An essential amino acid, commonly found at the active/catalytic site in proteins and enzymes. Arginine isn't assembled by the body, so it must be ingested, especially by people at a young age.
Sources of arginine include:
structural formula for arginine:
_ _
| H H | +
| \ / |
| N H H H H O |
| \\ \ / \ / // |
| C -- N -- C -- C -- C -- C -- C |
| / | / \ / \ \ |
| H -- N H H H H N O -- H |
| / / \ |
| H arginine H H |
|_ C6H15N4O2+ _|
| 
