1. Introduction

The concept of pProtons transport chains (PTCs) was deduced(H+) are vanished from the substrate-channelling hypothesis, which was experimentally demonstrated by Srivastava and Bernhard [14–16]. Critics of the substrate-channelling hypothesis have argued that free diffusion minimizes anydidactic biochemistry. A century ago, O.F. Meyerhof set glycolysis as the degradation of glucose (C₆H₁₂O₆) effects possibly provoked by substrate channellingo two molecules lactic acid 2 (C₃H₆O₃) [17]. We do not agree with this criticism for the following reasons. First of all, the substrate discussed to be transferred between two dehydrogenases is NADH [16]. Instead, we assert that the energy-rich NADH-H⁺ is prToday, the stoichiometry to metabolize glucose to two lactic acid is generally unknown. In 1953, H.A. Krebs was honoured with the Noduct/substrate ofle Prize for the dehydrogenases. If free diffusion oiscovery of the acid NADH-H⁺ into the citric acid cytosocl occurs, as an acid, NADH-H⁺ will ree. Krebs presented lactic acid acts with water to yield H⁺[H₂O]_n. Cosubstrate of a cycle unsidirequently, free diffusion of NADH-H⁺ entctionally cycling acils the change from an activds [2]. Today, the acid to an inactive salt. During reduction processes, it is clear that NADH-H⁺-anion pyruvate was considered as substrate of tKransfers two H. Therefore, a rationaleebs “citrate cycle”. The change from Krebs scientifically based on free diffusion would lead to inactivation of the reducing capacity of the co-enzyme NADH-H⁺. Secomodel to an alchemistic citrate cycle started quite early. In 1949 Kennedy and, the binding affinity of dehydrogenases for the co-enzyme excludes a concept based on free diffusion [18]. The binding of NADH-H⁺ to Lehninger investigated mitochondrial function on isolated mitochondria [3]. Kennedy and Lehninger used and enzyme frees the co-enzyme from the hydration layer. It is exactly this water-free binding of substrates to enzymes that allowed us to develop the PTC hypothesis. The term [mol/L] only applies to dissolved substrates. When bound to an enzyme, a substrate is no longer part of the aqueous layer, and both the position and movementdetermined carboxylates such as, pyruvate, malate, a-ketoglutarate and citrate. They discussed their data on basis of Krebs citric acid cycle, but phrases such as: “.oxidation of pyruvate and other intermediates of the substrate are defined, not random. This precise positioning stabilizes a specific subsKrebs cycle.” and “…aerobic citrate conformation, one prerequisite for optimal enzymatic activity.

2. The Proton Transport Chain Hypothesis

Our PTC hypothesi from pyruvate when malate s ensures that a water-free, intra-complex transfer of NADH-H⁺ rved as a source of oxaloacetate.” maintains the activity of the co-enzyme. The PTC hypothesis completely changes the overriding perspective of biological processes based on emitting entropy to a model of producing entropy. In addition, the changes include the mathematical modsquoted Krebs acid cycle. But, misquote is incorrect, because Kennedy and Lehninger missed to quote one manuscript of Krebs. Lehningers “citrate cycle” has conquered the world.

Kels usnned to calculate enzyme kinetics. For example, water-free conditions (mathematically) entail an infinite concentration [mol/L] of the substraty and Lehninger also mentioned “Fluoride was added to inhibit enolase and thereby exclude the application of a great number of commonly used mathematical formulae used to calculate enzyme kinetics. An infinite concentration changes enzymee end-point measured manometrically indicated the formation of 3-phoshoglyceric acid, which causes CO₂ klineticsberation from concentration dependency to complex kinetics and provision of substrate (mol/s).

In vivo, enzbicarbonate”. In Lehningers textbooks 3-phoshoglyceric acid as product of phosphoglymes such as muscle lactate dehydrogeerate kinase (LDH-m) and LDH-h act unidirectionally [19]. However, when they are investigated as isolated enzymes in vitro, they are disconnected from the flow of energy and material and act in a rPGK) catalysed reaction is simplified to 3-phosohoglycerateversible manner.

The PTC hypothesis provdides a mechanism explaining the observations in vivo that are not reproducible using traditional methods in the laboratory. The PTC hypothesis also integrates the well-known fact that in vivo, enzymes exist as organized complexes. Thus, we assert that the water-free NADH-H⁺ transcussed plasma membrane located PGK in complex with proton-linked monocarboxylate transporter 4 (MCT4). Permanent delivery of 3-phosfer from the proton donor, oglyceraldehyde 3-phophate dehydrogenase (GAPDH) to the proton acceptor, LDH-m ic acid drives MCT4 to unidirectionally drives the reduction of pyexport monocar⁻ tboxylic lac⁻. Thuids, in vivo, LDH-m (in complex with GA[4] [5] [6] [7].

PDH) only catalyses in the opposite direction the name of the enzyme suggests [20,21]. Citrate synthase is traditionally thought to be an enzyme that catalyses in only one direction. However, a couple of recent studies have reported citrate synthase enzymes capable of catalysingasma membrane located MCT1 is discussed in complex with carbonic anhydrase II (CAII). Permanent export of carbonic acid (H₂CO₃) dreversibly [22,23]. The enzymes characterized are both from bacteria, namely a sulphur-reducing anaerobic deltaproteobacterium,ives MCT1 to unidirectionally import monocarboxylic acids Desulfurella acetivorans[4] [225], and a chemol [6] [7].

Mitochotrophic bacteria,ndrial membrane located Thermosulfidibacter takaiiLDHh-MCT1 ABI70S6^Twas [23]. Adis bacteria do not have mitochondria, it is extremely difficult to draw comparisons with what happens in a eukaryotic cell. Metabolic enzymes within a eukaryotic cell are compartmentalized, separated by multiple membranes, exposed to different pH levels and are known to exist in enzyme cussed to catalyse the first reaction of Krebs citric acid cycle: oxidation of lactate to pyruvate and membrane transfer of pyruvic acid to the PDHc complexes. T. takaii ABI70S6^T acqu

Mires the carbon for metabolic processes from CO₂ iochondrial membran their environment. Therefore, considering that eukaryotes generate CO₂ f located LDHh-MCT1 was also introm glducose acquired from their environment, it is not surprising that these bacteria possess a cied to pyruvic acid to pyruvate carboxylase as substrate synthase capable of driving a reverse TCA cycle. Interestingly, characterization of the enzymes was performed in vitro using recombinant enzymesof oxaloacetic acid synthesis [4] [5] [6] [7]. Mor

Theover, anaerobic respiration was performed via fumarate reductase and not via succinate dehydrogenase (SDH)/complex II of the Citric Acid Cycle. Finally, we do not believe that the discovery that bacterial citrate synthase enzymes act reversibly in vitro has any bearing on the eukaryoticproposed citric acid cycle 1.1 balances burning of lactic acid and malic acid synthesis. Citric Acid Cycle concept. First, the eukaryotic enzyme is present on the human chromosome 12q13.3 and not a product oacid cycle 1.1 provides the mechanism of the mitochondrial genome. Therefore, it has likely diverged from its bacterial ancestor. Second, the condensation reaction catalysed by eukaryotic citrate synthase is practically irreversible, as it has a ΔG⁰′ data O.F. Meyerhof presented at his Noble Prize lecture: up-taken lactic acid is burned as well used as building blof −7.7 kcal/mol (−32.2 kJ/mol) [24k [8].

Combitrining enzyme complexes with PTCs creates a new and completely different understanding in Biology. The well-established didactically based sorting of glycolytic enzymes suggests single enzymes perform glycolysis, whereas our concept organizes enzymes into complexes optimizing energy and materialc acid cycle 1.1 illustrates the molecular mechanism for: synthesis is the product of degradation and thereby the transfer. A critical step in of the 4^th applying the tentative Fourth Law of Taw of thermodynamics to biological processes is the identification of the nature of the energy entity, ordering organisms. Glucose metabolism permanently creates the energy entity H⁺. Th [9]. Textbooks, such as A. Lehningers Biochemistry, propagate maximal entropy and thereby e energy of a H⁺ is high. The absoxclutde hydration free energy of the proton, ΔG_hyd(H⁺), haordered s been quoted in the literature to be from −252.6 kcal/mol to −262.5 kcal/mol, which corresponds to approximately 35-times the energy released by the hydrolysis of 1 mol of ATP [25]. Thus, H⁺ is ructures, such as membranes, enzyme-complexes, metabolons, organelways solvated, usually disolvated [26], and ‘free’ protons only exist in a chemical reaction written on a piece of paper. We illustrate this by combining H⁺ witles, cells, brief biologic systems, the PTC h yproton carriers, such as H⁺[H₂O]_n, NADH-H⁺, lactic acid (lacH), pyrH and H₂CO₃.othesis .  

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