32 - ORGANIC CHEMISTRY: FUNCTIONAL GROUPS AND THE MOLECULES OF BIOCHEMISTRY

Abstract

This chapter discusses the most common functional groups of the two main types, such as groups with only covalent single bonds and groups that include covalent double bonds. It explains the nomenclature of compounds containing those groups. The chapter describes proteins, carbohydrates, lipids, and nucleic acids, which are the molecules of biochemistry. A functional group is an atom or group that bonds to one or more carbon atoms in an organic molecule and contributes a characteristic chemical behavior to the molecule. In organic compounds, the OH group is usually covalently bonded and is called the hydroxyl group. The attachment of a hydroxyl group to an aromatic ring gives a class of organic compounds known as phenols, ArOH. Replacement of the hydrogen atoms of an ammonia molecule by hydrocarbon groups gives amines. The carbonyl group consists of a carbon atom and an oxygen atom joined by a covalent double bond. An aldehyde, RCHO, is a compound in which a hydrogen atom and a hydrocarbon group are bonded to a carbonyl group. Ketones are used extensively as solvents, especially in lacquers. A carboxylic acid, RCOOH, has a functional group that is a combination of a carbonyl group and a hydroxyl group. The chapter explains the concept of infrared and ultraviolet spectroscopy.