Exercise Physiology: Theory and Application to Fitness and Performance 9th Edition by Scott Powers, Edward Howley

Exercise 2

Briefly explain the concept of coupled reactions.

Step 1 of 2

Energy can neither be created nor be destroyed. It is converted from one form to another form. Cells need energy to perform various actions. The cells derive energy from the food an organism eats. The energy conserved in the chemical bonds of food molecules is trapped through the bioenergetic processes, and is used to drive cellular reactions. While some of the reactions are biochemical, the other reactions may involve mechanical energy.

Chemical reactions that occur in the cell are either exergonic or endergonic. While an exergonic reaction releases energy during the process, an endergonic reaction requires an input of energy to the reactants, for the reaction to occur.