Organic chemistry is the study of compounds that contain carbon atoms. These atoms share electrons with other atoms to form covalent bonds (see Bond ). Carbon atoms are unusual because they can form covalent bonds in many different ways, both with other carbon atoms and with other chemical elements. As a result, many kinds of carbon-containing compounds are possible. Scientists have identified several million organic compounds.
Organic compounds have many different structures and properties. A large number of simple organic compounds are obtained from plant and animal sources. For example, petroleum and natural gas contain many hydrocarbons from the remains of organisms that lived millions of years ago. Ethanol, a kind of alcohol, is formed by the fermentation of fruits, grains, and vegetables. Other, more complex organic compounds in living matter include amino acids (proteins), carbohydrates (sugars), lipids (fats), and nucleic acids (DNA and RNA). Inorganic compounds, which generally do not contain carbon, occur chiefly in rocks and in minerals.
Scientists once believed that carbon-containing compounds could be obtained only from living sources. However, in 1828, the German chemist Friedrich Wöhler prepared the organic compound urea in his laboratory. Since then, scientists have found many ways of making organic compounds from both organic and inorganic materials, and many important new compounds have been prepared in the laboratory. These compounds include medicines, insecticides, and chains of molecules called polymers (see Polymer ).
See also Chemistry .
