How do chemical equations for respiration and photosynthesis compare?

1 Answer
Jan 18, 2017

Well, one is the reverse of the other..........

Explanation:

AS you know, photosynthesis is the production of simple sugars from water and carbon dioxide:

#6CO_2(g) + 6H_2O(g) +Deltararr C_6H_12O_6(aq) +6O_2(g)#

And dioxygen is also produced as a bonus......

On the other hand, respiration involves combustion of sugars with dioxgen:

#C_6H_12O_6(aq) + 6O_2(g) rarr 6CO_2(g) + 6H_2O(l) + Delta#

Because the combustion reaction involves the formation of strong #C=O# bonds, this reaction is exothermic. And fixation of carbon dioxide, where strong #C=O# bonds are broken is endothermic. From where does the energy come? Have green plants an energy source that we cannot utilize?