What is the functional group represented by the -COOH structure?

The structure -COOH is characteristic of a carboxylic acid, which is defined by the presence of both a carbonyl group (C=O) and a hydroxyl group (–OH) attached to the same carbon atom. This combination gives carboxylic acids their unique properties, including the ability to donate protons (H+) in aqueous solutions, which is a key feature of acids.

Carboxylic acids are commonly found in various organic compounds and are important in many biochemical processes. The -COOH group is also responsible for the acidic nature of these compounds, distinguishing them from other groups.

In contrast, alcohols contain a hydroxyl group (-OH) attached to a saturated carbon atom, and amines consist of nitrogen attached to one or more carbon atoms. Esters are derived from carboxylic acids where the –OH group is replaced by an alkoxy group (-O-R). Understanding these functional groups helps to clarify their distinct chemical behaviours and reactivities.