Question

why is photosynthesis considered as an endothermic reaction​

Answer 1

Photosynthesis is an endothermic reaction because sunlight energy is absorbed during the process of photosynthesis by the plants. And our definition says that when in a reaction heat is absorbed it is termed as endothermic reaction. Plants absorb direct sun energy, CO2 and water to produce glucose and oxygen

Answer 2

Unlike many other endothermic reactions, photosynthesis does not absorb energy as heat. Instead, during plants absorb energy from sunlight to turn carbon dioxide and water into oxygen and glucose, which is a type of sugar molecule. The energy is stored in the glucose molecules, ready to be used when needed.