Energy is released from adenosine triphosphate (ATP) during cellular respiration through a process known as hydrolysis, which involves breaking the bonds between its phosphate groups.

To elaborate, ATP is a crucial molecule that functions as the primary energy currency of the cell. It consists of an adenosine molecule bonded to three phosphate groups. The bonds between these phosphate groups are considered high-energy bonds because they store a considerable amount of potential energy. During cellular respiration, this energy is harnessed to fuel various cellular activities.

The release of energy from ATP occurs through hydrolysis, a chemical reaction that incorporates a water molecule to cleave the bond between the second and third phosphate groups. This reaction is exothermic, meaning it releases energy that the cell can utilize. The products of this reaction are adenosine diphosphate (ADP) and a free inorganic phosphate group ($P_i$).

The energy liberated from ATP hydrolysis is employed in a multitude of cellular processes, including protein synthesis, muscle contraction, and active transport across cell membranes. Notably, this energy is not released as heat; rather, it is directly utilized to propel these essential functions.

ATP hydrolysis and the subsequent regeneration of ADP back to ATP form a continuous cycle within the cell. This cycle is sustained by the processes of cellular respiration, particularly the stages of glycolysis, the Krebs cycle, and oxidative phosphorylation. These metabolic pathways break down glucose and other nutrients to produce ATP, which is then available to support the cell’s activities.

In summary, the energy stored in the high-energy bonds of ATP is released through hydrolysis during cellular respiration. This energy is crucial for driving various cellular processes, highlighting the importance of ATP as an essential molecule for life.