IAC White Set Science Bee Practice Test 2026 – Complete Exam Prep Resource

ATPases are enzymes that hydrolyze ATP, removing a phosphate group to release energy for cellular work. In their action, the molecule being dephosphorylated is ATP (adenosine triphosphate), which is converted to ADP and inorganic phosphate. That’s why ATP is the substrate here. NAD and glucose are involved in other pathways and processes, not the dephosphorylation step performed by ATPases, and ADP is the product of ATP hydrolysis, not the substrate.