Nucleoside triphosphate

A nucleoside triphosphate is a molecule formed by a purine or pyrimidine binding to a carbohydrate (forming a nucleoside) bound to three phosphate groups, each of which are connected to each other by two pyrophosphate bonds. The main nucleoside triphosphates are ATP and GTP (purine nucleotides), CTP, UTP and TTP (pyrimidine nucleotides).