Dehydration Synthesis

∞ generated and posted on 2016.12.13 ∞

Joining of two compounds in association with the loss of a water molecule between them.

Dehydration Synthesis is the covalent joining of two compounds via the removal of one water molecule between them, an -H from one and an -OH from the other.

Protein, nucleic acid, and carbohydrate polymers as well as fats are all assembled (polymerized) via a series of dehydration synthesis reactions, which also can be described as condensation reactions or condensation polymerization.

Figure legend: Shown is the opposing chemical reaction going from top to bottom (dehydration synthesis, a.k.a., condensation reaction). Hydrolysis instead is shown going from bottom to top. Note the insertion of the water molecule into the central bond between subunits, also known as moieties at this point, such as in amino acid moiety.

The converse of dehydration synthesis is hydrolysis. Dehydration synthesis, that is, builds molecules up – at the expense of energy (endergonic reaction) – while hydrolysis breaks molecules apart, liberating energy (exergonic reaction).

ATP, for example, is synthesized from ADP and inorganic phosphate via an energy-requiring dehydration synthesis reactions, and is converted back to ADP in the course of a hydrolysis reaction.