scholarly journals Thermodynamics, kinetics and reaction chemistry of aerobic respiration

2019 ◽  
Author(s):  
Kelath Murali Manoj ◽  
Nikolai Mikhailovich Bazhin
Keyword(s):  
Proton Transport ◽  
Atp Synthesis ◽  
Electrical Energy ◽  
Reaction Model ◽  
Cellular Respiration ◽  
Aerobic Respiration ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Definite Answer ◽  
Kinetics Of

Three fundamental queries are addressed on the thermodynamics of aerobic cellular respiration (viz. ATP-synthesis and thermogenesis)- (1) Can the energy of oxygen reduction be utilized for proton transport?, (2) Is the trans-membrane proton differential harness-able as a potential energy capable of doing useful work?, and (3) If the movement of a miniscule amount of mitochondrial protons could give rise to a potential of ~200 mV and if such an electrical energy could sponsor ATP-synthesis. Further, we provide a definite answer to a fourth question- what is the thermodynamic role of protons in the oxygen-centric scheme of aerobic respiration? Finally, we demonstrate that the rotary ATPase activity of Complex V cannot account for physiological ATP synthesis and establish that the murburn reaction model explains the kinetics of mitochondrial oxidative phosphorylation.

scholarly journals Aerobic Respiration: Criticism of the Proton-centric Explanation Involving Rotary Adenosine Triphosphate Synthesis, Chemiosmosis Principle, Proton Pumps and Electron Transport Chain

2018 ◽  
Vol 11 ◽  
pp. 117862641881844 ◽  
Author(s):  
Kelath Murali Manoj
Keyword(s):  
Electron Transport ◽  
Adenosine Triphosphate ◽  
Electron Transport Chain ◽  
Atp Synthesis ◽  
Cellular Respiration ◽  
Aerobic Respiration ◽  
Proton Pumps ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Transport Chain ◽  
Interactive Dynamics

The acclaimed explanation for mitochondrial oxidative phosphorylation (mOxPhos, or cellular respiration) is a deterministic proton-centric scheme involving four components: Rotary adenosine triphosphate (ATP)-synthesis, Chemiosmosis principle, Proton pumps, and Electron transport chain (abbreviated as RCPE hypothesis). Within this write-up, the RCPE scheme is critically analyzed with respect to mitochondrial architecture, proteins’ distribution, structure-function correlations and their interactive dynamics, overall reaction chemistry, kinetics, thermodynamics, evolutionary logic, and so on. It is found that the RCPE proposal fails to explain key physiological aspects of mOxPhos in several specific issues and also in holistic perspectives. Therefore, it is imperative to look for new explanations for mOxPhos.

Kinetics of Proton-Transport-Coupled ATP Synthesis Catalyzed by the Chloroplast ATP Synthase

1986 ◽  
Vol 90 (11) ◽  
pp. 1034-1040 ◽  
Author(s):  
P. Gräber ◽  
P. Fromme ◽  
U. Junesch ◽  
G. Schmidt ◽  
G. Thulke
Keyword(s):  
Atp Synthase ◽  
Proton Transport ◽  
Atp Synthesis ◽  
Chloroplast Atp Synthase ◽  
Kinetics Of

Kinetics of hydrosilylation of tert-butylphenylketone by diphenylsilane catalysed by [Rh(1,5-COD)(-)-DIOP]+ClO-4

1980 ◽  
Vol 45 (8) ◽  
pp. 2224-2239 ◽  
Author(s):  
Ivan Kolb ◽  
Jiří Hetflejš
Keyword(s):  
Activation Parameters ◽  
Reaction Rates ◽  
Reaction Model ◽  
Initial Reaction ◽  
Title Reaction ◽  
Rate Determining Step ◽  
Kinetic Isotope ◽  
Arene Complex ◽  
Kinetics Of

Kinetic analysis of the title reaction has been made by the method of initial reaction rates. On the basis of the rate data, kinetic isotope effect and spectroscopic study of the reaction of the organosilicon hydride with the catalyst, the reaction model was proposed involving the following steps: the displacement of the diene by reaction with the silicon hydride from a rhodium-arene complex in an induction period of the hydrosilylation, the oxidative addition of the organosilicon hydride to the rhodium-arene complex, followed by the interaction of the ketone with the silylhydridorhodium (III) species in the rate determining step. The process is characterized by the following activation parameters: ΔU = 54.5 ± 8.5 kJ mol-1 and ΔS = -88± 25 J mol-1.K-1. The significant role of the entropic factor was supported by the analysis of the temperature dependence of the asymmetric efficiency of the catalyst.

Proton semiconductors and energy transduction in biological systems

1978 ◽  
Vol 235 (3) ◽  
pp. R99-R114 ◽  
Author(s):  
H. J. Morowitz
Keyword(s):  
Proton Transport ◽  
Hydrogen Transfer ◽  
Atp Synthesis ◽  
Present Theory ◽  
Energy Transduction ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Detailed Model ◽  
Hydrogen Ion Concentration

Energy transduction processes in biology are analyzed in terms of ordered chains of hydrogen bonds. The theory is an extension of studies on proton conductance in ice and is stimulated by current ideas on the role of hydrogen ions in oxidative phosphorylation and photophosphorylation. The possibility of a protochemistry paralleling electrochemistry is presented along with experimental evidence. The theory relating transmembrane electrochemical potential difference of hydrogen ion concentration to the synthesis of ATP is reviewed. The thermodynamics of hydrogen transfer across a membrane is treated including electrochemical and electromechanical factors. As a prelude to considering ATP synthesis, the acid-base dissociation reactions of ATP, ADP, and phosphate are analyzed. The thermodynamics of ATP synthesis is discussed and a detailed model is presented coupling the synthesis to proton transport. The model assumes a gated proton semiconductor that carries protons and allows them to interact specifically with well-defined substrate molecules. The physics of proton transport is outlined and various methods examined in the context of biological membranes. Emphasis is placed on solid-state proton semiconductors and the present theory of such structures is given. A section is included on possible biological applications of these semiconductors.

scholarly journals Stochastic rotational catalysis of proton pumping F-ATPase

2008 ◽  
Vol 363 (1500) ◽  
pp. 2135-2142 ◽  
Author(s):  
Mayumi Nakanishi-Matsui ◽  
Masamitsu Futai
Keyword(s):  
Proton Transport ◽  
Atp Synthesis ◽  
Energy Coupling ◽  
Proton Pumping ◽  
Proton Channel ◽  
Phosphate Binding ◽  
Stochastic Fluctuation ◽  
Rotational Catalysis ◽  
Α Helix

F-ATPases synthesize ATP from ADP and phosphate coupled with an electrochemical proton gradient in bacterial or mitochondrial membranes and can hydrolyse ATP to form the gradient. F-ATPases consist of a catalytic F 1 and proton channel F 0 formed from the α 3 β 3 γδϵ and ab 2 c 10 subunit complexes, respectively. The rotation of γϵ c 10 couples catalyses and proton transport. Consistent with the threefold symmetry of the α 3 β 3 catalytic hexamer, 120° stepped revolution has been observed, each step being divided into two substeps. The ATP-dependent revolution exhibited stochastic fluctuation and was driven by conformation transmission of the β subunit (phosphate-binding P-loop/α-helix B/loop/β-sheet4). Recent results regarding mechanically driven ATP synthesis finally proved the role of rotation in energy coupling.

scholarly journals Chemiosmosis principle versus murburn concept: Why do cells need oxygen? Deducing the underpinnings of aerobic respiration by mechanistic predictability

2019 ◽  
Author(s):  
Kelath Murali Manoj ◽  
Vidhu Soman ◽  
Vivian David Jacob ◽  
Abhinav Parashar ◽  
Daniel Andrew Gideon ◽  
...  
Keyword(s):  
Atp Synthesis ◽  
Cellular Respiration ◽  
Proton Pumps ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Alternative Scheme ◽  
Theoretical Concepts ◽  
Transport Chain ◽  
Experimental Strategies

The long-standing explanation for cellular respiration (mitochondrial oxidative phosphorylation, mOxPhos) in textbooks is proton-centric and involves the elements of Rotary ATP synthesis, Chemiosmosis principle, Proton pumps and Electron transport chain (in short, the RCPE model). Addressing certain lacunae in the RCPE model, an alternative scheme based on murburn concept was proposed in 2017 (Manoj, 2017). The new proposal is oxygen-centric in essence, and it advocates constructive roles for diffusible reactive oxygen species (DROS) in electron transfer reactions and ATP-synthesis. By the end of 2018, significant arguments and experimental evidences (in vitro, in situ, and in silico) had accumulated supporting the new mechanism. Herein, the authors compare the predictive capabilities of the two models. Theoretical concepts and expectations are detailed to differentiate the two models, and the correlations are cross-checked with the available data/information. Experimental strategies are further charted to delineate and demarcate the two hypotheses’ relevance in mOxPhos.

scholarly journals Mystery of the Toxic Flea Dip: An Interactive Approach to Teaching Aerobic Cellular Respiration

2004 ◽  
Vol 3 (1) ◽  
pp. 62-68 ◽  
Author(s):  
A. T. Baines ◽  
M. McVey ◽  
B. Rybarczyk ◽  
J. T. Thompson ◽  
H. R. Wilkins
Keyword(s):  
Small Groups ◽  
Real Life ◽  
Cellular Respiration ◽  
Aerobic Respiration ◽  
Interactive Approach ◽  
Group Discussions ◽  
Biology Students ◽  
Physiological Processes ◽  
Transport Chain

We designed an interrupted case study to teach aerobic cellular respiration to major and nonmajor biology students. The case is based loosely on a real-life incident of rotenone poisoning. It places students in the role of a coroner who must determine the cause of death of the victim. The case is presented to the students in four parts. Each part is followed by discussion questions that the students answer in small groups prior to a classwide discussion. Successive parts of the case provide additional clues to the mystery and help the students focus on the physiological processes involved in aerobic respiration. Students learn the information required to solve the mystery by reading the course textbook prior to class, listening to short lectures interspersed throughout the case, and discussing the case in small groups. The case ends with small group discussions in which the students are given the names and specific molecular targets of other poisons of aerobic respiration and asked to determine which process (i.e., glycolysis, citric acid cycle, or the electron transport chain) the toxin disrupts.

scholarly journals Murburn model of mitochondrial aerobic respiration is robust in comparison to the ‘chemiosmotic rotary or two-ion torsional’ ATP-synthesis proposals

2020 ◽  
Author(s):  
Daniel Andrew Gideon
Keyword(s):  
Oxidative Phosphorylation ◽  
Experimental Research ◽  
Atp Synthesis ◽  
Reaction Scheme ◽  
Aerobic Respiration ◽  
Evidence Based ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Paul Boyer ◽  
Intense Debate ◽  
Biophysical Chemistry

One of the most fundamental questions in biology pertains to how mechano-chemical energy is derived from metabolic fuels. In particular, how oxidation of NADH is linked to ATP synthesis in mitochondrial oxidative phosphorylation (mOxPhos) has been a topic of intense debate. Together, the Peter Mitchell-Paul Boyer proposals for mOxPhos are termed herein as “chemiosmotic rotary ATP synthesis” (or CRAS) model, which was recently defended/advocated by Pedro Silva in Biophysical Chemistry . Over the last two decades, Sunil Nath had questioned some aspects of the CRAS proposal, and made subtle alterations on the roles of Complex V and ions within the reaction scheme, and continues to advocate his framework as “two-ion torsional ATP synthesis” (abbreviated herein as TITAS) model in Biophysical Chemistry . Kelath Murali Manoj had revisited the data on the respiratory machinery’s structures/distributions and based on two-decades of evidence-based experimental research in redox enzymology of heme/flavin proteins, had formulated the murburn model for mOxPhos. In this work, the ETC-CRAS hypothesis and its off-shoot, the TITAS proposal, are questioned in the light of the convincing chemicophysical logic provided by the murburn hypothesis.

143 Stimulated glycolysis is able to maintain ATP levels and motility of bull spermatozoa submitted to mitochondrial depolarisation

2020 ◽  
Vol 32 (2) ◽  
pp. 198
Author(s):  
J. Losano ◽  
J. Padín ◽  
I. Méndez-López ◽  
D. Angrimani ◽  
N. Montez ◽  
...  
Keyword(s):  
Atp Synthesis ◽  
The Other ◽  
Atp Levels ◽  
Other Hand ◽  
Significant Difference ◽  
Carbonyl Cyanide ◽  
Bovine Spermatozoa ◽  
Kinetics Of ◽  
Glucose Supplementation

Studies have reported the importance of mitochondria in sperm metabolism. However, for some species, glycolysis appears to be as essential as oxidative phosphorylation in sperm physiology. On the other hand, these mechanisms have not been fully elucidated for bovine spermatozoa. Therefore, the aim of this study was to evaluate the role of mitochondria and glycolysis in ATP synthesis and sperm kinetics of bovine spermatozoa. For this purpose, sperm from seven bovine epididymides (n=7) was collected and diluted to a concentration of 100×106 spermatozoamL−1 in Tyrode's albumin lactate pyruvate medium. Then, each sample was divided into 10 aliquots and evaluated in a 2×5 factorial design, with the first factor being the presence or absence of glucose (5mM) to stimulate glycolysis and the second factor being treatment with the mitochondrial uncoupler carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP; 0, 0.1, 0.3, 1, and 3 µM) to deplete mitochondrial ATP. Sperm samples were subjected to measurements of ATP levels using a luminescence technique (CellTiter-Glokit, Promega), with ATP levels measured in duplicate. In addition, sperm samples were subjected to computerised analysis of total and progressive motilities (ISAS, Proiser). Statistical analysis was performed using SAS (SAS Institute Inc.), where the interaction between the factors was analysed using PROC GLM and the comparison between groups was performed using means analysis of variance (least significant difference test). It was considered significant at 5%. Adenosine triphosphate was lower at FCCP concentrations of 0.3 µM (180.3±31.9nM), 1 µM (220.2±40.4nM), and 3 µM (272.3±70.4nM) than at 0 µM (control; 448.6±63.7nM) and 0.1 µM (422.4±41.5nM) in the absence of glucose. However, in the groups treated with FCCP supplemented with glucose, ATP concentrations did not differ among the groups (0 µM: 577.2±70.4 nM; 0.1 µM: 610.8±57.8 nM; 0.3 µM: 606.2±64.2 nM; 1 µM: 670.9±61.9 nM; 3 µM: 696.1±68.5nM). Additionally, total motility was lower in FCCP-treated groups without glucose supplementation. On the other hand, total motility increased in the groups treated with 0.3, 0.1, 1, and 3 µM FCCP supplemented with glucose. A similar effect was verified for progressive motility. Based on these results, we can suggest that glucose supplementation is able to maintain ATP levels and motility in bull sperm undergoing FCCP-induced mitochondrial depolarisation.

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