Type of chemical reaction that involves the loss of water from the reacting molecules. in biological systems, it usually refers to the production of larger, biomolecules or polymers from smaller monomers.

The type of chemical reaction is dehydration synthesis.
Polymers are large molecules formed by combining monomers, theses monomers combined to each other by making a covalent bond. When these polymers are formed from monomers, water molecules are released as byproduct. This is called dehydration synthesis.