organic chemistry

Look at almost anything that was once alive or made to live among us — the wood of a chair, the sugar in your tea, the cotton in a shirt, a tablet of aspirin, the plastic of your phone case, the fuel in a car — and you are looking at organic chemistry. It is the branch of chemistry that studies compounds built around carbon. Centuries ago people thought such substances could only come from living things and carried a mysterious 'vital force', which is where the old word 'organic' comes from; that idea was wrong, and chemists now make countless 'organic' molecules from scratch in the lab.

More precisely, organic chemistry is the study of the structure, properties, reactions and synthesis of carbon-containing compounds, especially those in which carbon bonds to hydrogen and to other carbons. The whole subject rests on one fact: a carbon atom can form four strong, stable bonds and can chain to other carbons endlessly, so the same handful of atoms — carbon, hydrogen, oxygen, nitrogen and a few more — can be arranged into millions of different molecules. Organic chemists learn to read those arrangements, predict how they will react, and build new ones on purpose.

This matters because organic molecules are the stuff of life and of modern materials: every protein, every strand of DNA, every medicine, dye, fuel and polymer is an organic compound. One honest warning about the name: 'organic' here means 'carbon-based', and has nothing to do with pesticide-free food at the grocery store. A few simple carbon compounds — carbon dioxide, carbonates, diamond — are traditionally counted as inorganic, so the boundary is partly a matter of convention rather than a sharp law of nature.