Answer: A substance made up of atoms of two or more different elements joined by chemical bonds. Organic compounds. Compounds that contain bonds between carbon atoms. The four major groups of organic compounds are carbohydrates, proteins, lipids, and nucleic acids.
<em>Organic compound, any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen. The few carbon-containing compounds not classified as organic include carbides, carbonates, and cyanides. </em>
