Can thermodynamic quantity, delta G, be used to predict the speed of a reaction in a living organism? Why and why not?
No. Delta G can be used to determine if a reaction is at equilibrium and/or spontaneous (or not spontaneous) but it tells you nothing about the rate of a reaction.
Yes, thermodynamic quantity delta G, also known as Gibbs free energy change, can be used to predict the speed of a reaction in a living organism to some extent. Delta G represents the energy difference between the reactants and products of a chemical reaction and is related to the spontaneity of the reaction.
In a living organism, reactions occur in the context of a complex biochemical network. While delta G provides information about whether a reaction will occur spontaneously or not, it does not provide direct information about the speed or rate of the reaction. The rate of a reaction is determined by factors such as the activation energy, the concentration of reactants, and the presence of catalysts or enzymes.
However, delta G can still be a useful guide in predicting the reaction speed in some cases. A reaction with a highly negative delta G value (-ΔG), meaning a large decrease in Gibbs free energy, is likely to be thermodynamically favorable and can proceed spontaneously. Moreover, a more negative delta G value indicates a greater driving force for the reaction and, thus, a potentially higher reaction rate.
It is worth noting that other factors beyond thermodynamics, such as enzyme activity and substrate availability, can also significantly influence the speed of reactions in living organisms. Therefore, while delta G can provide a rough indication of the thermodynamic feasibility of a reaction, it alone cannot fully predict the speed of a reaction in a living organism.
Yes, the thermodynamic quantity delta G (Gibbs free energy change) can be used to predict the speed of a reaction in a living organism to some extent. Delta G provides information about the spontaneity and direction of a chemical reaction. It combines both the enthalpy change (delta H) and the entropy change (delta S) of the reaction.
In living organisms, reactions occur under specific physiological conditions, such as temperature and pH, which can determine the delta G value. If the delta G value is negative (delta G < 0), it indicates that the reaction is thermodynamically favorable and spontaneous, meaning it will proceed on its own. This suggests that the reaction has the potential to occur at a relatively faster rate.
However, it is important to note that delta G alone cannot solely predict the speed of a reaction in a living organism. This is because the speed of a reaction is influenced by various factors like the presence of enzymes, catalysts, and the concentration of reactants.
Enzymes are biological catalysts that accelerate reactions by lowering the activation energy required for the reaction to proceed. They achieve this by providing an alternative reaction pathway with a lower activation energy. Enzymes can significantly increase the rate of a reaction, even if the delta G value is not highly negative.
Additionally, the concentration of reactants can also influence the speed of the reaction. Even if the delta G value suggests that the reaction is thermodynamically favorable, if the concentration of reactants is low, the reaction may still proceed slowly.
Therefore, while delta G provides valuable insights into the thermodynamics of a reaction, other factors such as enzymes and reactant concentrations must also be considered to accurately predict the speed of a reaction in a living organism.