ශ්වසනයේදී සිදුවන ප් රතික් රියා විශාල අනු කුඩා අණු බවට බිදහෙලන අපවෘත්තිය ක් රියා වේ., which break large molecules into smaller ones, releasing energy in the process, as weak so - called "high - energy" bonds are replaced by stronger bonds in the products. respiration is one of the key ways a cell releases chemical energy to fuel cellular activity. cellular respiration is considered an exothermic redox reaction which releases heat. the overall reaction occurs in a series of biochemical steps, most of which are redox reactions themselves. although cellular respiration is technically a combustion reaction, it clearly does not resemble one when it occurs in a living cell because of the slow release of energy from the series of reactions.