Organic chemistry is a specific discipline within chemistry which involves the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of chemical compounds consisting primarily of carbon and hydrogen, which may contain any number of other elements, including nitrogen, oxygen, halogens as well as phosphorus, silicon and sulfur.
The original definition of "organic" chemistry came from the misperception that these compounds were always related to life processes, but it has been shown that this is not the case (See Historical highlights). Moreover, it is known that life also depends heavily on inorganic chemistry; for example, many enzymes rely on transition metals such as iron and copper; and materials such as shells, teeth and bones are part organic, part inorganic in composition. Apart from elemental carbon, inorganic chemistry deals only with simple carbon compounds, with molecular structures which do not contain carbon to carbon connections (its oxides, acids, salts, carbides, and minerals). This does not mean that single-carbon organic compounds do not exist (viz. methane and its simple derivatives). Biochemistry mainly deals with the chemistry of proteins (and other large biomolecules).
Because of their unique properties, multi-carbon compounds exhibit extremely large variety and the range of application of organic compounds is enormous. They form the basis of, or are important constituents of many products (paints, plastics, food, explosives, drugs, petrochemicals, and many others) and of course (apart from a very few exceptions) they form the basis of all life processes.
The different shapes and chemical reactivities of organic molecules provide an astonishing variety of functions, like those of enzyme catalysts in biochemical reactions of live systems. The autopropagating nature of these organic chemicals is what life is all about.
Because of the special properties of carbon, it is likely that life in other star systems would be carbon-based, in spite of speculations about the possibility of substituting silicon, which lies just below carbon in the periodic table.
Trends in organic chemistry include chiral synthesis, green chemistry, microwave chemistry, fullerenes and microwave spectroscopy.