Final answer:
ATP (adenosine triphosphate) is the molecule produced during both photosynthesis and cellular respiration to provide energy for cellular functions.
Step-by-step explanation:
The molecule that is produced during both photosynthesis and cellular respiration to power chemical reactions is ATP (adenosine triphosphate). ATP is the energy currency of the cell, providing the power needed for work, such as muscle movement. While photosynthesis uses sunlight to convert carbon dioxide and water into glucose and oxygen, cellular respiration breaks down glucose in the presence of oxygen to release carbon dioxide, water, and energy in the form of ATP. The energy stored in glucose from photosynthesis is thus transferred to ATP during cellular respiration, which is then used by the cells to perform various functions.