Final answer:
Energy is released when ATP is hydrolyzed into ADP and an inorganic phosphate. This process is essential for providing the energy necessary for various cellular activities.
Step-by-step explanation:
Energy is released during the conversion of ATP to ADP. When a cell requires energy, ATP (adenosine triphosphate) is hydrolyzed into ADP (adenosine diphosphate) and an inorganic phosphate (Pi). This process releases energy, which is then used by the cell to perform various functions such as muscle contraction, nerve impulse transmission, and synthesis of biomolecules.
The general equation for ATP hydrolysis is:
ATP + H₂O → ADP + Pi + energy
This reaction often happens during cell metabolism, for example, during the second half of glycolysis, and it is part of the light-independent reactions when ATP and NADPH are used to convert 3-PGA into G3P.