<P> In humans, approximately 60 percent of the energy released from the hydrolysis of one mole of ATP produces metabolic heat rather than fuel the actual reactions taking place . Due to the acid - base properties of ATP, ADP, and inorganic phosphate, the hydrolysis of ATP has the effect of lowering the pH of the reaction medium . Under certain conditions, high levels of ATP hydrolysis can contribute to lactic acidosis . </P> <P> Hydrolysis of the terminal phosphoanhydridic bond is a highly exergonic process . The amount of released energy depends on the conditions in a particular cell . Specifically, the energy released is dependent on concentrations of ATP, ADP and P . The further the concentrations are from equilibrium the greater the absolute value of Gibbs free energy change (ΔG) will be . In standard conditions (ATP, ADP and P concentrations are equal to 1M, water concentration is equal to 55M) the value of ΔG is between - 28 to - 34 kJ / mol . </P> <P> The variability of the ΔG value exists, because this reaction is also dependent on the concentration of Mg cations . The cation Mg plays a role in stabilizing the ATP molecule . But the conditions in a cell are far from the standard state . In fact the ΔG in standard conditions would mean that the concentrations are close to equilibrium . And if cells were actually at equilibrium the change in Gibbs free energy would be zero . That would mean, that no energy is acquired by ATP hydrolysis, and that would have fatal consequences for the organism . Because this reaction is often coupled with thermodynamically unfavorable reactions, to give an overall negative (spontaneous) change in Gibbs free energy (ΔG) for the reaction sequence . </P> <P> The outcome of ATP hydrolysis is dependent not only on the studied organism, but also on the tissue or even the compartment within the cell . The current demand for energy must be taken into account as well . Variability in the ΔG are therefore to be expected . It is important to realize how far away are the actual concentrations from the standard condition concentrations . They are lower by three orders of magnitude (standard condition values are in M and in reality they are in mM). Because these concentrations are so low, the reaction will be energetically more favorable . </P>

How do you release the energy from a molecule of atp