Answer:
Both are opposite cellular metabolisms; one being anabolic while the other being catabolic breaking down the products synthesized in the other (photosynthesis).
Explanation:
Both photosynthesis and respiration are cellular metabolisms intertwined in the sense that photosynthesis assembles the products of respiration while respiration on the other hand breaks down the product of photosynthesis.
Photosynthesis is a metabolic (anabolic) process unique to the cells of organisms called autotrophs. Autotrophs including plant have the ability, using their Chlorophyll to trap the energy from sunlight and use it to power the combination of C02 and water (H2O) to produce glucose.
6C02 + 6H2O -------> C6H12O6 + 6O2
On the other hand, all living organisms including the photosynthetic organisms themselves require energy to power their life processes. They obtain this energy by breaking down organic food molecules (glucose) in the presence or absence of oxygen to produce CO2, water and ATP (energy currency of the cell). This process is called CELLULAR RESPIRATION.
C6H12O6 + 6O2 ------> 6CO2 + 6H2O
The relationship between these two processes is that photosynthesis utilizes CO2 and H2O as reactants to produce glucose (products), while respiration uses glucose as reactant to produce CO2 and H2O (products). Hence, products of one is the reactant of the other.
