Talk:Endergonic reaction

Please do not merge these separate 6 pages

The merge debate goes back to '05 (see: Talk:Endergonic). The result of the debate was to not merge. Moreover, it is standard protocol, e.g. according to both The Essential Dictionary of Science (Clark 2004) and the A to Z Dictionary of Thermodynamics (Perrot 1998), to have separate entries for such closely-related but subtly-different topics such as:

• Exothermic – a process or reaction that involves the release of energy; usually in the form of heat.
• Exothermic reaction – a chemical reaction in which heat is give out.

As well as for the other terms: endothermic, endothermic reaction, etc. For example, the melting of an ice-cube is an endothermic process; combustion evolves an exothermic reaction, warm-blooded animals are endothermic, arguing with other Wikipedians is an endergonic activity, etc. Help us expand on these separate stubs, but please don't merge. Wikipedia has unlimited storage space. Articles are sure to grow. Thanks:--Sadi Carnot 17:30, 22 March 2006 (UTC)

However, could it be justified to explain the distinction between 'endergonic' and 'endothermic' in the article, and ditto for 'exo-'? 72.24.227.225 (talk) 04:05, 14 September 2022 (UTC)

"Making Endergonic reactions happen" is misleading

Endergonic reactions never happen. The methods in the "Making Endergonic reactions happen" section don't make endergonic reactions happen; instead they change endergonic reactions into exergonic ones. For example, the first one ("Pull") decreases the concentration, and therefore the chemical potential, of the products, which causes $\Delta G_{r}$ to decrease until it becomes negative, i.e. the reaction becomes exergonic. Semantics, or crucial distinction? You decide, because I have to finish my thermodynamics homework. —Keenan Pepper 02:57, 13 March 2007 (UTC)

The article defines an endergonic reaction as one for which the standard change in free energy is positive. Jheald 08:41, 13 March 2007 (UTC)

True, but this section is still deeply misleading since the examples imply that energy can be "borrowed" to make endergonic reactions "happen". It would be much better phrased in terms of chemical equilibrium i.e. even if the equilibrium is heavily biased towards reactants, if the products are constantly being chewed up, then eventually all the reactants will proceed through the reaction. —Preceding unsigned comment added by 84.92.241.186 (talk) 10:37, 27 October 2007 (UTC)

"Reagents can be pulled through an endergonic reaction, if the reaction products are cleared rapidly by a subsequent exergonic reaction." Isn't the article already saying exactly what you are asking for? Jheald 11:03, 27 October 2007 (UTC)

2 in the diagram is wrong

The difference between the energy of the transition state and the free energy of the products as indicated by (2) in the diagram is not equal to the energy change of the reaction (deltaG). The deltaG is measured as the difference between the free Energy of the reactants and the free energy of the products. The energy of the transition state does not have any influence on this. — Preceding unsigned comment added by 87.245.72.60 (talk) 14:42, 26 December 2013 (UTC)

Why standard temperature and pressure?

Under constant temperature and constant pressure conditions, this means that the change in the standard Gibbs free energy would be positive

$\Delta G^{\circ }>0$

for the reaction at standard state (i.e. at standard pressure (1 bar), and standard concentrations (1 molar) of all the reagents).

The reference to standard state seems totally gratuitous and irrelevant here. An endergonic reaction is defined as one that would require a positive change in the Gibbs free energy at constant temperature and pressure. That is a fully general definition, and it is clear that the "endergonicity" of a reaction is therefore a function of temperature, pressure and concentration. Why then the sudden anchoring to standard state? Are we not allowed to apply this utterly fundamental thermodynamic concept except at standard state? 178.38.83.46 (talk) 22:44, 8 March 2015 (UTC)