Amines are a type of organic molecule that is derived from ammonia. They tend to have distinctive and unpleasant odors that are reminiscent of rotting fish. Despite their unpleasant smells, they are critical to the survival of life. Amines help create amino acids, which then help build living proteins. Many vitamins — substances that are critical to sustaining life — are also built out of amines.
Generally, an amine is a molecule that centers around a single atom of nitrogen. This nitrogen is usually connected to two hydrogen atoms and to a single group of other atoms. This is, however, only a general rule. One or both of the hydrogen atoms can be replaced by groups of other atoms and the molecule can still be classified as an amine.
Beside the amines that the human body is built out of, humankind has found important uses for a number of others. Demerol™ and morphine are used as analgesics — generally known as pain relievers. Novocaine and similar compounds are used as anesthetics. Ephedra is an important decongestant. Tetramethylammonium iodide is used to disinfect drinking water.
Serotonin is generally considered to be an important amine, as it functions as one of the primary neurotransmitters used by the brain. It regulates feelings of heat and hunger, and controls how fast the brain operates. Serotonin affects feelings of happiness, and forms a part of the brain's ability to regulate the waking and sleeping cycle.
Amines have many other functions as well. Some are used for industrial applications, such as tanning and pest control. Aniline is used in the production of man-made dyes. Cadaverine and putrescine produce the odor of rotting, decaying flesh. Some amines, such as amphetamines and methamphetamines, are even used as recreational drugs.
Like ammonia, amines are bases, meaning that they have a pH above seven. Due to this fact, they can be neutralized by acids. When this occurs, they form alkylammonium salts, which themselves have many important properties. One of these salts, choline, is involved in the production of some of the other neurotransmitters that make the human brain work.
Amines are classified as primary, secondary, or tertiary, depending on how many groups of organic compounds are bonded to the central nitrogen atom. An amine with two hydrogen atoms and one organic group is a primary amine. One with one hydrogen atom and two organic groups is secondary, while a nitrogen atom with three organic groups is called tertiary.