karboxýlhóp

The carboxyl group, often written as -COOH, is a functional group in organic chemistry. It consists of a carbonyl group (C=O) bonded to a hydroxyl group (-OH). This specific arrangement of atoms gives the carboxyl group its characteristic properties. It is the defining functional group of carboxylic acids, which are organic compounds that contain one or more carboxyl groups.

Carboxyl groups are polar due to the electronegativity of the oxygen atoms. This polarity allows them to form hydrogen bonds, which influences the solubility and boiling points of compounds containing them. The hydrogen atom in the hydroxyl part of the carboxyl group is weakly acidic. This means it can dissociate in water, releasing a proton (H+) and forming a carboxylate anion (-COO-). The acidity of carboxylic acids varies depending on the other substituents present in the molecule.

Carboxyl groups are ubiquitous in biochemistry. They are found in amino acids, the building blocks of proteins, and in fatty acids, which are components of lipids. The carboxylate form is typically predominant at physiological pH. This functional group plays a crucial role in many biological processes, including metabolism and signaling. Its presence also impacts the overall charge and reactivity of biomolecules.