Definition
Anabolism
Anabolism is the synthetic half of metabolism: the set of enzyme-catalysed reactions that assemble complex biomolecules from simpler precursors, consuming energy.
Formally, for precursors assembled into a product ,
so the reaction is unfavourable on its own and must be driven by coupling to an energy-releasing process, typically the hydrolysis of ATP. Anabolism is what builds structure — proteins, nucleic acids, polysaccharides — and is therefore the constructive counterpart to catabolism.