Where does the water molecule come from during large molecul

Where does the water molecule come from during large molecules synthesis reaction?

Solution

During large molecules synthesis reaction, either the hydrogen (-H) of one monomer (molecule I) combines with the hydroxyl group (-OH) of another monomer (molecule II) resulting in the formation of a molecule of water (H2O), or two hydrogens (H2) from one monomer (molecule I) combine with one oxygen (-O-) from the other monomer (molecule II) releasing a molecule of water. The two monomers join by a Covalent bond to form a large polymer.

(Enzyme/ Catalyst)

Case-1: Monomer(1) -H + OH- Monomer(2) --------------------------------------------------------------) Polymer + H20

(large molecule)   

(Enzyme/ Catalyst)

Case-2: Monomer(1) -H2 + O- Monomer(2) ---------------------------------------------------------------) Polymer + H20

  (large molecule)