Why is respiration considered an exothermic reaction ? Explain.

Exothermic reaction is a reaction in which energy is released in the form of heat or light.In exothermic reaction total energy of product is less than total energy of reactants.
In case of Respiration: Respiration is a chemical process in which cells of an organism obtain energy by combining glucose and oxygen forming carbon dioxide,water and energy.,
Respiration is called an exothermic reaction because energy is released in the process of forming carbon dioxide and water by combining glucose and oxygen.

$$ \;\;\; C_{6}H_{12}O_{6}(aq) + 6O_{2}(g) $$

$$ \downarrow$$

$$ \;\;\; 6CO_{2}(aq) + 6H_{2}O (L) + Energy $$