How many K calories of energy are released upon breaking the terminal phosphate of an ATP molecule?

The correct answer is based on the amount of energy released when the terminal phosphate group is cleaved from an ATP molecule. When ATP (adenosine triphosphate) undergoes hydrolysis to form ADP (adenosine diphosphate) and an inorganic phosphate, approximately 7.3 K calories of energy are released. This energy is available for cellular processes and is a vital reason why ATP is often called the "energy currency" of the cell.

The energy released during this reaction is due to the breaking of a high-energy phosphoanhydride bond, which is significant in the context of biochemistry and metabolic energy transfer. This energy is utilized by cells to perform various functions, including muscle contraction, active transport, and biosynthesis. Understanding this value is crucial for comprehending how energy metabolism operates in biological systems.