Where does the energy come from to add a uracil to the 3' end of a transcript?

The hydrolysis of pyrophosphate from the approaching UTP atom. The term pyrophosphate is additionally the name of esters framed by the buildup of a phosphorylated organic compound with inorganic phosphate, concerning dimethylallyl pyrophosphate. This bond is likewise alluded to as a high-vitality phosphate bond.