Amine

An amine is an organic chemical containing a nitrogen atom with tetrahedral arrangement of it electron pairs and its lone pair of electrons. The atoms bonded to nitrogen can be any chemical group except for a carbonyl group. In that case, the compound is called an amide. Amines are related to ammonia (NH₃) and have one or more of the protons present in ammonia replaced by a carbon atom. Methylamine, CH₃NH₂, is the smallest amine. When the nitrogen atom is bonded to one, two, three or four carbon atoms, the chemical is called a primary amine, secondary amine, tertiary amine or quaternary amine, respectively.

The amino group, NH₂, is a functional group which serves as a site for chemical reactivity. Amines are basic, like ammonia, meaning that they can accept protons from protic acids or donate electrons to Lewis bases. Thus, dimethylamine (CH₃)₂NH can be protonated by a strong acid to become a dimethylammonium ion, (CH₃)₂NH₂⁺. Amines typically have a "fishy" odor.

In biochemistry, amines act on biogenic amine receptors.