dehydrationcondensation

Dehydration-condensation, commonly referred to as a dehydration synthesis or condensation reaction, is a type of chemical reaction in which two molecular units are joined to form a larger molecule with the concurrent elimination of a water molecule. The process typically involves the removal of a hydrogen atom from one partner and a hydroxyl group from the other, creating a new covalent bond and releasing water. The specific bond formed depends on the reacting functional groups, such as an ester linkage (C–O–C) in esterification, an amide (N–C) in peptide formation, or a glycosidic bond (C–O–C) between sugar units.

Key examples include the formation of disaccharides from monosaccharides (for instance, glucose units condensing to form maltose with water release), peptide bond formation between amino acids during protein synthesis, and esterification reactions that produce esters. In polymer chemistry, dehydration condensation underlies condensation polymerization, where bifunctional monomers react to form long chains (for example, polyesters) with water as a byproduct. Nucleotide polymerization into nucleic acids also proceeds via dehydration steps that connect sugar-phosphate backbones, although biological contexts often involve additional enzymatic regulation.

Equilibrium considerations are important: removing water or using dehydrating conditions shifts the reaction toward product formation. Dehydration-condensation is distinct from hydrolysis, which cleaves bonds by adding water. It plays a central role across biochemistry, carbohydrate chemistry, and polymer science, enabling the construction of complex molecules and macromolecules.