7 research outputs found
Mitochondrial physiology
Get PDFAs the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Mitochondrial physiology
Get PDFAs the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Thermochromic and Photoresponsive Cyanometalate Fe/Co Squares: Toward Control of the Electron Transfer Temperature
No full textTwo structurally related and photoresponsive cyanide-bridged Fe/Co square complexes, {Fe2Co2}, are reported: {[(TpMe)Fe(CN)3]2[Co(bpy)2]2[(TpMe)Fe- (CN)3]2}·12H2O (2) and {[(TpMe)Fe(CN)3]2[Co-(bpy)2]2[BPh4]2}·6MeCN (3), where TpMe and bpy are hydridotris(3-methylpyrazol-1-yl)borate and 2,2′-bipyridine, respectively....
Thermochromic and Photoresponsive Cyanometalate Fe/Co Squares: Toward Control of the Electron Transfer Temperature
No full textTwo
structurally related and photoresponsive cyanide-bridged Fe/Co
square complexes, {Fe<sub>2</sub>Co<sub>2</sub>}, are reported: {[(Tp<sup>Me</sup>)Fe(CN)<sub>3</sub>]<sub>2</sub>[Co(bpy)<sub>2</sub>]<sub>2</sub>[(Tp<sup>Me</sup>)Fe(CN)<sub>3</sub>]<sub>2</sub>}·12H<sub>2</sub>O (<b>2</b>) and {[(Tp<sup>Me</sup>)Fe(CN)<sub>3</sub>]<sub>2</sub>[Co(bpy)<sub>2</sub>]<sub>2</sub>[BPh<sub>4</sub>]<sub>2</sub>}·6MeCN (<b>3</b>), where Tp<sup>Me</sup> and bpy
are hydridotris(3-methylpyrazol-1-yl)borate and 2,2′-bipyridine,
respectively. Through electrochemical and spectroscopic studies, the
Tp<sup>Me</sup> ligand appears to be a moderate σ donor in comparison
to others in the [NEt<sub>4</sub>][(Tp<sup>R</sup>)Fe<sup>III</sup>(CN)<sub>3</sub>] series [where Tp<sup>R</sup> = Tp, hydridotris(pyrazol-1-yl)borate;
Tp<sup>Me</sup> = hydridotris(3-methylpyrazol-1-yl)borate; pzTp =
tetrakis(pyrazol-1-yl)borate; Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate;
Tp*<sup>Me</sup> = hydridotris(3,4,5-trimethylpyrazol-1-yl)borate].
The spectroscopic, structural, and magnetic data of the {Fe<sub>2</sub>Co<sub>2</sub>} squares indicate that thermally-induced intramolecular
electron transfer reversibly converts {Fe<sup>II</sup><sub>LS</sub>(μ-CN)Co<sup>III</sup><sub>LS</sub>} pairs into {Fe<sup>III</sup><sub>LS</sub>(μ-CN)Co<sup>II</sup><sub>HS</sub>} units near
ca. 230 and 244 K (<i>T</i><sub>1/2</sub>) for <b>2</b> and <b>3</b>, respectively (LS: low spin; HS: high spin).
These experimental results show that <b>2</b> and <b>3</b> display light-induced {Fe<sup>III</sup><sub>LS</sub>(μ-CN)Co<sup>II</sup><sub>HS</sub>} metastable states that relax to thermodynamic
{Fe<sup>II</sup><sub>LS</sub>(μ-CN)Co<sup>III</sup><sub>LS</sub>} ones at ca. 90 K. Ancillary Tp<sup>R</sup> ligand donor strength
appears to be the dominant factor for tuning electron transfer properties
in these {Fe<sub>2</sub>Co<sub>2</sub>} complexes
Assessing haemorrhage-critical values of cerebral blood flow by modelling biomechanical stresses on capillaries in the immature brain
No full text
