Life on Earth is based on a vast array of organic or carbon-based compounds. All species of plants and animals use them for structure and biological functioning.

Carbon is unique among the known elements. As a nonmetal, it forms covalent bonds. A carbon atom can form four bonds, so it can combine with several other atoms in many different ways, thereby yielding a huge variety of diverse molecules.

Most chemicals known today are organic, and many of them are found in nature. But chemists have also synthesized millions of organic compounds not found in nature.

Chemists classify organic molecules according to the functional groups they contain. A functional group is a specific combination of bonded atoms that reacts in a characteristic and predictable way.

We'll use functional groups as a way of exploring the structure and function of organic compounds. We'll start by learning the names and formulas of some biologically important functional groups, then consider the structure and function of food energy molecules and nitrogen-containing molecules.

Objectives