Why ATP is preffed over CTP GTP TTP UTP as energyproviding molecule?

Answer 1

The amounts of ATP found in a healthy cell are often mirrored by GTP, and provide similar amounts of energy as these are both purine nucleotides. They are not only energy providing molecules but they also send signals.

Answer 2

Because Adenosin triphosphate ATP has the highest capacity to store AND release energy from its electronic bonds. the other compounds do not have same capacity to store AND release energy on their phosphate links