Final answer:
Photosynthesis is an endothermic process that requires energy input in the form of light, creating glucose; cellular respiration is an exothermic process that releases energy by breaking down glucose to produce ATP.
Step-by-step explanation:
Photosynthesis is endothermic, meaning that it requires the input of energy/light to occur. Whereas cellular respiration is exothermic, meaning the release of energy occurs. Photosynthesis utilizes energy from the sun to build carbohydrates like glucose, which are then used in cellular respiration to produce ATP (adenosine triphosphate). In contrast, cellular respiration metabolizes these carbohydrates to generate ATP, and during this process, energy is released, which is then used for various cellular activities.