"Suppose that, as indicated in the figure, the catalyst affects only the forward reaction. In its presence, the sum of the forward rates would clearly be larger than otherwise, while the backward rate would be unchanged. The position of equilibrium would therefore shift to the right, by the law of mass action. If we suppose further that the reaction produces heat q when it occurs, then a violation of the second law would be possible. We first allow equilibrium to be reached without the catalyst...and then add the catalyst, and heat δq is produced as the equilibrium is shifted. This heat is used to run a machine, and thus do work, cooling the system back to its original temperature in the process. We then remove the catalyst and the equilibrium shifts back. Heat δq is now extracted from the surroundings, which must warm the system back to the ambient temperature. A cycle has therefore been completed for which the net effect has been the isothermal conversion of heat energy into work, and a perpetual motion machine of the second kind has been found. We conclude that the supposed situation is impossible and that the catalyst must accelerate the forward and backward reactions equally." https://dtk.tankonyvtar.hu/bitstream/handle/123456789/8903/B9780120442621500128.pdf

The following conditional can be extracted from the above text:

If the second law of thermodynamics is true, catalysts accelerate the forward and backward reactions equally.

The consequent, "catalysts accelerate the forward and backward reactions equally", is false, and therefore the second law of thermodynamics is false as well (logic forbids the combination "true antecedent, false consequent"):

"However, many enzymes reversibly convert their substrate and product, and if one is interested in catalysis in only one direction, it may be necessary to prevent the reverse reaction...This is the first demonstration, on a specific example, that slowing a step that is rate limiting only when the enzyme works in one direction is a general mechanism for biasing the enzyme in the other direction." https://hal.science/hal-01977597/document

"PtO-clusters were found to have a pivotal role in unidirectional suppression of undesirable H2 oxidation [the backward reaction] in photocatalytic water cleavage process. More importantly, these PtO-clusters can also demonstrate excellent efficiency in hydrogen evolution rate [the forward reaction].." https://www.nature.com/articles/ncomms3500

"Interestingly, although [FeFe]-hydrogenases all possess the same active site H cluster, they display a large range of H2 gas oxidation and proton reduction activities, with some displaying a dramatic catalytic bias, that is, the propensity of a catalyst to effect rate of acceleration in one reaction direction over the other. " https://europepmc.org/article/pmc/pmc8653774

"The protein scaffold around an enzyme’s catalytic core exquisitely controls reactivity, including the direction and rate of chemical processes. Scientists refer to this fine tuning as “catalytic bias”—and how it occurs remains widely debated...A research team from three U.S. Department of Energy (DOE) national laboratories and four universities found that subtle changes to the environment surrounding some enzymes can not only change the rate of a cellular reaction by a staggering six orders of magnitude but also its direction. That reversal—the root of the catalytic bias dilemma—is like speeding in one direction at 10 miles-per-second, then going in the opposite direction at 1,000,000 miles-per-second." https://www.pnnl.gov/news-media/remarkable-rate-return-catalytic-bias

"Traditional catalysis is a central pivot around which much of the industrial and biological worlds turn. Positive catalysts satisfy three general principles. First, they increase reaction rates by providing lower activation energies for rate-limiting steps. Second, they are not consumed by their net reactions although they are intimately involved in them. Third, they do not alter final thermodynamic equilibria of their reactions. Epicatalysts bend this third principle in that they shift the final gas-phase equilibria of reactions." https://www.sciencedirect.com/science/article/pii/S2213138818301838

"In 2000, a simple, foundational thermodynamic paradox was proposed: a sealed blackbody cavity contains a diatomic gas and a radiometer whose apposing vane surfaces dissociate and recombine the gas to different degrees (A_2 ⇌ 2A). As a result of differing desorption rates for A and A_2 , there arise between the vane faces permanent pressure and temperature differences, either of which can be harnessed to perform work, in apparent conflict with the second law of thermodynamics. Here we report on the first experimental realization of this paradox, involving the dissociation of low-pressure hydrogen gas on high-temperature refractory metals (tungsten and rhenium) under blackbody cavity conditions. The results, corroborated by other laboratory studies and supported by theory, confirm the paradoxical temperature difference and point to physics beyond the traditional understanding of the second law." https://link.springer.com/article/10.1007/s10701-014-9781-5

Pentcho Valev https://twitter.com/pentcho_valev

Enzymes dramatically increase the rate of metabolic reactions but the main function of most of them is to favour one direction over the other and so to make the reaction more or less unidirectional. Metaphorically speaking, their main function is to violate the second law of thermodynamics:

"Catalytic bias refers to the relative rate preference of a catalyst for either the forward or reverse direction. In enzymatic metal cofactor-based oxidation–reduction catalysis, the tuning of catalytic bias plays an underlying role in controlling rates of reactivity. For this, enzymes have evolved complex active sites that can exist in multiple oxidation states with differing reduction potentials in order to achieve challenging multi-step, oxidation–reduction reactions. Conceivably, the relative stability of the intermediates that contribute to determining the rate-limiting step of the catalytic cycle could impose catalytic bias, although mechanisms for this concept are just beginning to be realized. As one example, recent work on Clostridium pasteurianum [FeFe]-hydrogenases which catalyze reversible hydrogen oxidation have shown that the differential stabilization/destabilization of active site oxidation states through either static or dynamic protein interactions can preferentially promote either the hydrogen oxidation or proton reduction direction of the reaction." https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119951438.eibc2770

"This has resulted in a deeper understanding of the hydrogenase model system and the ability to directly influence catalytic bias. Thus, the work presented here represents key progress towards developing unidirectional catalysts, and demonstrates the possibility of targeted, rational design and implementation of unidirectional catalysts." https://scholarworks.montana.edu/xmlui/handle/1/14621

"When enzymes are optimized for biotechnological purposes, the goal often is to increase stability or catalytic efficiency. However, many enzymes reversibly convert their substrate and product, and if one is interested in catalysis in only one direction, it may be necessary to prevent the reverse reaction...We evidence a novel strategy for tuning the catalytic bias of an oxidoreductase, which consists in modulating the rate of a step that is limiting only in one direction of the reaction, without modifying the properties of the active site." https://pubs.acs.org/doi/10.1021/ja301802r

So an anti-second-law technology is quickly developing, and at the same time the idiotic consequences of the second law of thermodynamics are universally taught. Post-truth (post-sanity) science:

"In the presence of a catalyst, BOTH THE FORWARD AND REVERSE REACTION RATES WILL SPEED UP EQUALLY, thereby allowing the system to reach equilibrium faster. However, it is very important to keep in mind that the addition of a catalyst has no effect whatsoever on the final equilibrium position of the reaction. It simply gets it there faster. [...] If the addition of catalysts could possibly alter the equilibrium state of the reaction, this would violate the second rule of thermodynamics..." https://courses.lumenlearning.com/introchem/chapter/the-effect-of-a-catalyst/

"As is true of any catalyst, enzymes do not alter the equilibrium point of the reaction. This means that the enzyme accelerates the forward and reverse reaction by precisely the same factor." http://www.columbia.edu/itc/chemistry/ARCHIVE/chem-c2407_f99/problems/kinetics1.pdf

Pentcho Valev https://twitter.com/pentcho_valev

On 2023-03-20 09:57:43 +0000, Pentcho Valev said:

> Enzymes dramatically increase the rate of metabolic reactions but the
> main function of most of them is to favour one direction over the other
> and so to make the reaction more or less unidirectional. Metaphorically
> speaking, their main function is to violate the second law of
> thermodynamics:

Absolute bollocks. Why don't you stick to Einstein's wickedness and
leave the 2nd Law of Thermodynamics alone, as it's clear that you know
nothing relevant.

(Ihave devoted 50 years of my life to the study of enzymes and
enzyme-catalysis. So although I may not know much about relativity I
know a great deal about enzyme-catalysis. Go back and read all the
discussiion of this when you were spouting similar nonsense in the
1990s.)

--
athel -- biochemist, not a physicist, but detector of crackpots

On Monday, March 20, 2023 at 2:38:47 PM UTC+1, Athel Cornish-Bowden wrote:

> Absolute bollocks. Why don't you stick to Einstein's wickedness and
> leave the 2nd Law of Thermodynamics alone, as it's clear that you know
> nothing relevant.

You belong to the brotherhood of thermodynamics deniers, Cornish. Why do you hate brothers heretics?

Athel Cornish-Bowden: "The concept of entropy was introduced to thermodynamics by Clausius, who deliberately chose an obscure term for it, wanting a word based on Greek roots that would sound similar to "energy". In this way he hoped to have a word that would mean the same to everyone regardless of their language, and, as Cooper [2] remarked, he succeeded in this way in finding a word that meant the same to everyone: NOTHING. From the beginning it proved a very difficult concept for other thermodynamicists, even including such accomplished mathematicians as Kelvin and Maxwell; Kelvin, indeed, despite his own major contributions to the subject, never appreciated the idea of entropy [3]. The difficulties that Clausius created have continued to the present day, with the result that a fundamental idea that is absolutely necessary for understanding the theory of chemical equilibria continues to give trouble, not only to students but also to scientists who need the concept for their work." https://www.beilstein-institut.de/download/712/cornishbowden_1.pdf

Athel Cornish-Bowden <athel.cb@gmail.com> wrote:

> On 2023-03-20 09:57:43 +0000, Pentcho Valev said:
>
> > Enzymes dramatically increase the rate of metabolic reactions but the
> > main function of most of them is to favour one direction over the other
> > and so to make the reaction more or less unidirectional. Metaphorically
> > speaking, their main function is to violate the second law of
> > thermodynamics:
>
> Absolute bollocks. Why don't you stick to Einstein's wickedness and
> leave the 2nd Law of Thermodynamics alone, as it's clear that you know
> nothing relevant.
>
> (Ihave devoted 50 years of my life to the study of enzymes and
> enzyme-catalysis. So although I may not know much about relativity I
> know a great deal about enzyme-catalysis. Go back and read all the
> discussiion of this when you were spouting similar nonsense in the
> 1990s.)

Yes. All those wannabee second kind machines
are based on sometimes subtle errors.
A forgotten heat transfer,
or a change in the chemical potential somewhere,
or yet something else.
It is just that analysis of what went wrong
is more subtle for second kind machines.

The ultimate remedy is of course the same as for the first law.
Let those who propose a perpetuum mobile of the second kind build one,
and demonstrate the production of unlimited free energy.
The second law will not be given up before someone really does that,

Jan