- An endothermic process absorbs heat or energy from the surroundings. The temperature of the surroundings typically decreases. - An exothermic process releases heat or energy into the surroundings. The temperature of the surroundings typically increases. - Photosynthesis converts light energy into chemical energy stored in glucose: $6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Light Energy} \rightarrow \text{C}_6\text{H} _{12}\text{O}_6 + 6\text{O}_2$.