Question

Using the formulas for photosynthesis and for respiration, explain how these two processes are connected.

Answer 1

Cellular respiration is the process of putting energy from glucose into a usable form in a molecule called ATP. It is a series of complex biochemical reactions where all the energy stored in glucose (which stores a lot) is transferred to other molecules, which can use it more efficiently.

The equation of respiration is

C6H12O6+6O2→6CO2+6H2O+energy in ATP

Photosynthesis can be thought of as the opposite reaction. Photosynthesis absorbs energy, rather than emits energy. Plant cells which photosynthesise take in CO2 and H2O from the atmosphere and light energy from the sun, and undergo the reaction

6CO2+6H2O+energy from sun→C6H12O6+6O2

The two are clearly dependent on each other. Without photosynthesis, there wouldn't be any glucose or oxygen which kick off the respiration reaction.