What Is An Organic Compound?

Organic compounds are simply defined as compounds that contain carbon. We then ask, why is an entire branch of Chemistry devoted to the study of carbon-containing compounds? We study organic chemistry because just about all of the molecules that make life possible (proteins, enzymes, vitamins, lipids, carbohydrates and nucleic acids) contain carbon. Thus the chemical reactions that take place in living systems, including our own bodies, are reactions of organic compounds. Most of the compounds found in nature such as those we rely on for food, medicine, clothing (cotton, wool, silk) and energy (natural gas, petroleum are organic as well.

Organic compounds are not however limited to those found in nature alone. Chemists have learnt to synthesize millions of organic compounds never found in nature, including synthetic fabrics, plastics, medicines, and so on. Many of these synthetic compounds prevent shortages of naturally occurring products.

But what makes carbon so special? Why are there so many carbon-containing compounds? The answer lies in Carbon`s position in the periodic table. Carbon is in the centre of the second row of elements. We see that atoms to the left of carbon such as Lithium, Beryllium and Boron have a tendency to give up electrons, whereas the atoms to the right such as Nitrogen, Oxygen and Fluorine have a tendency to accept electrons.

Because carbon is in the middle, it neither readily gives up nor readily accepts electrons. Instead, it shares electrons. Carbon can share electrons with several kinds of atoms and it can also share electrons with other carbon atoms. Consequently, carbon is able to form millions of stable compounds with a wide range of chemical properties simply by sharing electrons.

When we study organic chemistry, we study how organic compounds react. When an organic compound reacts, some bonds break and some new bonds form. Bonds form when two atoms share electrons, and bonds break when two atoms no longer share electrons. How readily a bond forms and how easily it breaks depends on the particular electrons that are shared, which, in turn, depend on the atoms to which the electrons belong. So the study of organic chemistry at the beginning, must start with an understanding of the structure of an atom including what electrons an atom has and where they are located.