Final answer:
Cells store energy temporarily in ATP molecules when they break down food molecules. This energy is then used in various cellular processes in a controlled and temporary manner, rather than being released all at once or as body heat.
Step-by-step explanation:
When cells break down food molecules, energy is stored temporarily in ATP molecules (adenosine triphosphate). ATP is the energy currency of cells, which stores energy for later use by body cells. During catabolic reactions, which break down large organic molecules into smaller ones, energy stored in chemical bonds is released. Approximately 40 percent of this energy is directly transferred to ATP. The ATP then carries this energy to where it is needed for cellular activities such as muscle contraction, nerve signal conduction, and biosynthesis. Once ATP is at the location where energy is required, it is broken down and a controlled amount of energy is released for the cell to perform its functions. It is important to note that the energy release is controlled and temporary, not in uncontrolled bursts or entirely as body heat.