ATP is thermodynamically suited as a carrier of phosphoryl groups in animal cells because of all except it is hydrolyzed in cells without enzyme action.
Why is ATP used as energy source?
The energy currency of the cell is ATP as it releases a large amount of energy on the release of second and third phosphate group. To be hydrolyzed, ATP requires enzyme action.
The structure of ATP consists of adenosine backbone, ribose sugar bound to three phosphate groups.
It is stable inside the cells and also functions as a signaling molecule, helps in synthesis of DNA and RNA.
Most of the ATP is synthesized in the mitochondria through aerobic respiration.
ATP serves as a carrier of phosphoryl group because it is stable and used as an intermediate for group transfer reactions.