Nicotine is a psychoactive amine, or nitrogen-containing compound, found in tobacco. The molecule is responsible for many of tobacco's physiological effects, including appetite suppression and increased ability to focus. The chemical properties of biomolecules stem from both their elemental components and the manner in which atoms of those elements are arranged into the overall molecular shape. There are three elements that comprise nicotine.
Carbon
In organic and bioorganic molecules, meaning molecules that are important to or have an effect upon living organisms, carbon is a key element. This is because carbon forms the "backbone" or "skeleton" of all organic molecules. While carbon skeletons aren't particularly chemically reactive in and of themselves, they nevertheless provide a scaffold to which other, more reactive elements are connected, and also help to determine the overall shape of the molecule. According to the "CRC Handbook of Chemistry and Physics," the carbon skeleton of nicotine consists of two connected ring structures, one made up of six atoms--five of which are carbon--and one made up of five atoms, four of which are carbon.
Nitrogen
While all the elements that make up nicotine are important to its physiological activity, nitrogen is perhaps the most essential with regard to nicotine's effect upon the brain. Molecules must have certain shapes and contain certain elements to bind to receptors in the brain and induce psychological responses. Most psychoactive molecules are nitrogen-containing, because nitrogen has chemical properties that help it bind to brain receptors, explain Drs. Reginald Garrett and Charles Grisham in their book, "Biochemistry." Like other psychoactive chemicals, including morphine, heroin, and many therapeutic pharmaceuticals, the nitrogen in nicotine lends it the ability to bind to brain receptors and produce effects such as suppressed appetite and increased physiological arousal.
Hydrogen
The third and most prevalent element in nicotine is hydrogen. The nicotine molecule consists of 10 carbon atoms and only two nitrogen atoms, but 14 hydrogen atoms. While hydrogen atoms form the bulk of the elemental composition of nicotine by quantity, however, they account for only a small portion of its mass--less than 9 percent of the mass of nicotine is made up of hydrogen, according to the "CRC Handbook of Chemistry and Physics."
Hydrogen accounts for very little of nicotine's overall shape, ability to bind to receptors in the body, and chemical reactivity. While hydrogen atoms bound to atoms of certain other elements, such as oxygen and nitrogen, are chemically reactive, hydrogen atoms bound to carbon rarely react. All nicotine's hydrogen atoms are bound to carbon, making the atoms essentially fixed and nonreactive in the molecule.
References
- "CRC Handbook of Chemistry and Physics"; David Lide; 1974
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
