Final answer:
During hydrolysis of ATP, it loses a phosphate group, resulting in an increase in entropy and release of energy.
Step-by-step explanation:
During hydrolysis of ATP, it loses a(n) phosphate group, which results in an increase in entropy. When ATP is hydrolyzed into ADP and a phosphate group, the high-energy phosphate bond is broken, releasing energy that can be used for cellular reactions. This hydrolysis reaction is considered an exergonic reaction, meaning it releases energy.