Main Page | See live article | Alphabetical index Chemically, an imino acid is any molecule that contains both imino (-NH-) and carboxylic acid functional groups. Proline (one of the 20 'amino acids' encoded in DNA) is an imino acid as the nitrogen is bound to two carbons an only one hydrogen. In an amino group the nitrogen is in the form -NH2. This article is a stub. You can help Wikipedia by fixing it. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.