Question: why are cellular respiration and photosynthesis considered cycles of coupled reactions?
Answer: Cellular respiration is a complex set of enzyme-catalyzed reactions that break apart glucose, making 6 molecules of CO2 along the way. ... So, the glucose and O2 created by photosynthesis is used in respiration to make CO2 and water - the materials needed in photosynthesis. In this way, these two reactions are coupled.