ATPhydrolyzing

ATPhydrolyzing is the biological process by which adenosine triphosphate (ATP) is cleaved by hydrolysis to release usable energy for cellular work. The fundamental reaction most commonly carried out is ATP plus water yielding adenosine diphosphate (ADP) and inorganic phosphate (Pi), though some reactions produce adenosine monophosphate (AMP) and pyrophosphate (PPi). The hydrolysis reaction is energetically favorable, providing energy that powers a wide range of cellular activities. In cells, ATP hydrolysis typically occurs in the presence of a divalent metal ion such as Mg2+, which stabilizes the transition state and affects the actual free energy change.

Enzymes that catalyze ATP hydrolysis are collectively known as ATPases. They include P-type ATPases (for example, Ca2+-ATPase and Na+/K+-ATPase) that drive active transport across membranes, F-type and V-type ATPases that couple ATP hydrolysis to proton transport or generate a proton motive force, and various motor and AAA+ ATPases involved in mechanical work or protein remodeling. ATP hydrolysis is also tightly integrated into the function of motor proteins such as myosin, kinesin, and dynein, where it drives conformational changes that enable movement along cytoskeletal tracks. Other ATPases participate in substrate transport (ABC transporters), protein folding (e.g., chaperones that use ATP to remodel client proteins), and signal transduction.

The energy released by ATP hydrolysis is a key driver of cellular metabolism, often used in coupling endergonic processes to exergonic ones, thereby supporting growth, maintenance, and response to environmental changes.