Semantic search

This page or action requires JavaScript to work, please enable JavaScript in your browser or use a browser where this is supported so that functionality can be served and is provided as requested. For further assistance, please have a look at the noscript help page.

Search Clear all entries

Term	Abbreviation	Description
French Group of Bioenergetics	FGoB	The French Group of Bioenergetics...
Full screen		By clicking/enabling Full screen in the Graph-menu in DatLab the currently selected graph is shown alone on the full screen (On) or together with the other defined graphs (Off). Full screen is particularly useful for a single channel overview and for Copy to clipboard [ALT+G B].
Fumarase	FH	Fumarase or fumarate hydratase (FH) is an enzyme of the tricarboxylic acid cycle catalyzing the equilibrium reaction between fumarate and malate. Fumarase is found not only in mitochondria, but also in the cytoplasm of all eukaryotes.
Fura2		Fura2 is a ratiometric fluorescence probe for the measurement of calcium. Its derivative Fura-2-acetoxymethyl ester (Fura2-AM) is membrane permable and can thus be used to measure intracellular free calcium concentration (Grynkiewicz et al., 1985). For this purpose, cells are incubated with Fura2-AM, which crosses the cell membrane by diffusion and is cleaved into free Fura2 and acetoxymethyl groups by cellular esterases. Intracellular free calcium is measured by exciting the dye at 340 nm and 380 nm, which are the excitation optima of calcium-bound and free Fura2, respectively, and emission detection above 500 nm. Through the ratiometric detection unequal distribution of the dye within the cell and other potential disturbances are largely cancelled out, making this a widely used and relatively reliable tool for calcium measurements.
GM-pathway control state	GM	GM: Glutamate & Malate. MitoPathway control state: NADH electron transfer-pathway state The GM-pathway control state (glutamate-malate pathway control state) is established when glutamate&malate are added to isolated mitochondria, permeabilized cells and other mitochondrial preparations. Glutamate and transaminase are responsible for the metabolism of oxaloacetate, comparable to the metabolism with acetyl-CoA and citrate synthase.
GMS-pathway control state	GMS	GMS: Glutamate & Malate & Succinate. MitoPathway control: NS Transaminase catalyzes the reaction from oxaloacetate to 2-oxoglutarate, which then establishes a cycle without generation of citrate. OXPHOS is higher with GS (CI&II) compared to GM (CI) or SRot (CII). This documents an additive effect of convergent CI&II electron flow to the Q-junction, with consistent results obtained with permeabilized muscle fibres and isolated mitochondria (Gnaiger 2009).
Gain		The gain is an amplification factor applied to an input signal to increase the output signal.
Gas constant	R [J·mol^-1·K^-1]	The gas constant, R = 8.314462618 J·mol^-1·K^-1, has the SI unit for energy per amount per temperature. R is primarily known from the ideal gas equation, pV = nRT or p = cRT. Therefore, RT is the ratio of pressure p and concentration c. R = f·F, the electrochemical constant f times the Faraday constant F. R = k·N_A, the Boltzmann constant k times the Avogadro constant N_A.
Getting started - DatLab		Users have to enter their user details the first time they use DatLab 8 on a specific computer. As well, entering some basic settings is required when connecting DatLab 8 with an O2k for the first time.
Gibbs energy	G [J]	Gibbs energy G [J] is exergy which cannot be created internally (subscript i), but in contrast to internal-energy (d_iU/dt = 0) is not conserved but is dissipated (d_iG/dt < 0) in irreversible energy transformations at constant temperature and (barometric) pressure, T,p. Exergy is available as work in reversible energy transformations (100 % efficiency), and can be partially conserved when the exergonic transformation is coupled to an endergonic transformation.
Glucose	Glc	Glucose, also known as D-glucose or dextrose, is a monosaccharide and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate.
Glutamate	G	Glutamic acid, C₅H₉NO₄, is an amino acid which occurs under physiological conditions mainly as the anion glutamate^-, G, with pK_a1 = 2.1, pK_a2 = 4.07 and pK_a3 = 9.47. Glutamate&malate is a substrate combination supporting an N-linked pathway control state, when glutamate is transported into the mt-matrix via the glutamate-aspartate carrier and reacts with oxaloacetate in the transaminase reaction to form aspartate and oxoglutarate. Glutamate as the sole substrate is transported by the electroneutral glutamate^-/OH^- exchanger, and is oxidized in the mitochondrial matrix by glutamate dehydrogenase to α-ketoglutarate (2-oxoglutarate), representing the glutamate-anaplerotic pathway control state. Ammonia (the byproduct of the reaction) passes freely through the mitochondrial membrane.
Glutamate dehydrogenase	mtGDH	Glutamate dehydrogenase, located in the mitochondrial matrix (mtGDH), is an enzyme that converts glutamate to α-ketoglutarate [1]. mtGDH is not part of the TCA cycle, but is involved in glutaminolysis as an anaplerotic reaction.
Glutamate-anaplerotic pathway control state	G	G: Glutamate is an anaplerotic NADH-linked type 4 substrate (N). When supplied as the sole fuel substrate in the glutamate-anaplerotic pathway control state, G is transported by the electroneutral glutamate-/OH- exchanger, and is oxidised via mt-glutamate dehydrogenase in the mitochondrial matrix. The G-pathway plays an important role in glutaminolysis.
Glutamate-aspartate carrier		The glutamate-aspartate carrier catalyzes the electrogenic antiport of glutamate^- +H⁺ for aspartate^-. It is an important component of the malate-aspartate shuttle in many mitochondria. Due to the symport of glutamate^- + +H⁺, the glutamate-aspartate antiport is not electroneutal and may be impaired by uncoupling. Aminooxyacetate is an inhibitor of the glutamate-aspartate carrier.
Glycerophosphate	Gp	Glycerophosphate (synonym: α-glycerophosphate; glycerol-3-phosphate; C₃H₉O₆P) is an organophosphate and it is a component of glycerophospholipids. The mitochondrial Glycerophosphate dehydrogenase Complex oxidizes glycerophosphate to dihydroxyacetone phosphate and feeds electrons directly to ubiquinone.
Glycerophosphate dehydrogenase Complex	CGpDH	Glycerophosphate dehydrogenase complex (CGpDH) is a Complex of the electron transfer-pathway localized at the outer face of the mt-inner membrane. CGpDH is thus distinguished from cytosolic GpDH. CGpDH oxidizes glycerophosphate to dihydroxyacetone phosphate and feeds two electrons into the Q-junction, thus linked to an ET pathway level 3 control state.
Glycerophosphate pathway control state	Gp	The glycerophosphate pathway control state (Gp) is an ET-pathway level 3 control state, supported by the fuel substrate glycerophosphate and electron transfer through glycerophosphate dehydrogenase Complex into the Q-junction. The glycerolphosphate shuttle represents an important pathway, particularly in liver and blood cells, of making cytoplasmic NADH available for mitochondrial oxidative phosphorylation. Cytoplasmic NADH reacts with dihydroxyacetone phosphate catalyzed by cytoplasmic glycerophos-phate dehydrogenase. On the outer face of the inner mitochondrial membrane, mitochondrial glycerophosphate dehydrogenase oxidises glycerophosphate back to dihydroxyacetone phosphate, a reaction not generating NADH but reducing a flavin prosthesic group. The reduced flavoprotein donates its reducing equivalents to the electron transfer-pathway at the level of CoQ.
Glycerophosphate shuttle	Gp shuttle	The glycerophosphate shuttle makes cytoplasmic NADH available for mitochondrial oxidative phosphorylation. Cytoplasmic NADH reacts with dihydroxyacetone phosphate catalyzed by cytoplasmic glycerophosphate dehydrogenase. On the outer face of the inner mitochondrial membrane, glycerophosphate dehydrogenase complex (mitochondrial glycerophosphate dehydrogenase) oxidizes glycerophosphate back to dihydroxyacetone phosphate, a reaction not generating NADH but reducing a flavin prosthesic group. The reduced flavoprotein transfers its reducing equivalents into the Q-junction, thus representing a ET pathway level 3 control state.
Gnaiger 2019 MiP2019
Graph control - DatLab		A combination of mouse and keyboard commands provides convenient control of graphs in DatLab 8.
Graph layout - DatLab		» See Layout for DatLab graphs.
Graph options - DatLab		Several display options can be applied to a DatLab graph under Graph options.
Group		See population.
H2DCFDA	DCF, H2-DCF	H2DCFDA (dichlorodihydrofluorescein diacetate) is a cell permeant fluorescent probe that has been used as an indicator of ROS presence. It is a reduced form of fluorescein that does not present fluorescence. After entry in the cell, it suffers deacetylation by intracellular esterases, and upon oxidation it is converted to dichlorofluorescein (excitation wavelength ~492–495 nm, emission ~517–527 nm). It may be oxidised by hydrogen peroxide, hydroxyl radical, hypochlorite anion, nitric oxide, peroxyl radical, peroxynitrite, singlet oxygen and superoxide. Has been used as a general indicator of ROS by fluorescence microscopy.
HPTS	HPTS	8-Hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) is a ratiometric pH fluorophore; pKa = 7.3. Relative molecular mass: M_r = 524.39
Harmonization		Harmonization is the process of minimizing redundant or conflicting standards which may have evolved independently. To obtain a common basis in reaching a defined objective, critical requirements are identified that need to be retained.
Harmonized European norm	EN-norm	Harmonized European norms are norms valid for all members of the European Union. They are mandatory parts of the individual national collections of norms.
Harmonized SUIT protocols	H-SUIT	Harmonized SUIT protocols (H-SUIT) are designed to include cross-linked respiratory states. When performing harmonized SUIT protocols in parallel, measurements of cross-linked respiratory states can be statistically evaluated as replicates across protocols. Additional information is obtained on respiratory coupling and substrate control by including respiratory states that are not common (not cross-linked) across the harmonized protocols.
Harmonized standard		A harmonized standard is a European standard developed by a recognized European Standards Organisation: CEN, CENELEC, or ETSI.
Healthy ageing		Healthy ageing: 'WHO has released the first World report on ageing and health, reviewing current knowledge and gaps and providing a public health framework for action. The report is built around a redefinition of healthy ageing that centres on the notion of functional ability: the combination of the intrinsic capacity of the individual, relevant environmental characteristics, and the interactions between the individual and these characteristics' (Beard 2016 The Lancet).
Healthy reference population	HRP	A healthy reference population, HRP, establishes the baseline for the relation between body mass and height in healthy people of zero underweight or overweight, providing a reference for evaluation of deviations towards underweight or overweight and obesity. The WHO Child Growth Standards (WHO-CGS) on height and body mass refer to healthy girls and boys from Brazil, Ghana, India, Norway, Oman and the USA. The Committee on Biological Handbooks compiled data on height and body mass of healthy males from infancy to old age (USA), published before emergence of the fast-food and soft-drink epidemic. Four allometric phases are distinguished with distinct allometric exponents. At heights above 1.26 m/x the allometric exponent is 2.9, equal in women and men, and significantly different from the exponent of 2.0 implicated in the body mass index, BMI [kg/m²].
Heat	Q, Q_th [J]	Heat is a form of energy [J]. The relationship between heat and work provides the foundation of thermodynamics, which describes transformations from an initial to a final state of a system. In energy transformations heat may pass through the boundary of the system, at an external heat flow of d_eQ/dt.
Height of humans	h [m]; H [m·x^-1]	The height of humans, h, is given in SI units in meters [m]. Humans are countable objects, and the symbol and unit of the number of objects is N [x]. The average height of N objects is, H = h/N [m/x], where h is the heights of all N objects measured on top of each other. Therefore, the height per human has the unit [m·x^-1] (compare body mass [kg·x^-1]). Without further identifyer, H is considered as the standing height of a human, measured without shoes, hair ornaments and heavy outer garments.
Heterothermy		Heterothermy is the variable regulation of body temperature in endotherms which can change their body temperatures as levels of activity and environmental conditions dictate (e.g. hibernators). In regional heterothermy, temperature gradients are present, e.g. between body core and extremeties.
Hexokinase	HK	The hexokinase catalyzes the phosphorylation of D-glucose at position 6 by ATP to yield D-glucose 6-phosphate as well as the phosphorylation of many other hexoses like D-fructose, D-mannose, D-glucosamine.
Heymsfield 2014 Am J Clin Nutr
High signal at zero oxygen		A high signal at zero oxygen may be observed during zero calibration (R0). First, check the quality of the dithionite solution. The following instructions show how to distinguish between a defective sensor head and an electrical leak current.
High-resolution respirometry	HRR	High-resolution respirometry, HRR, is the state-of-the-art approach in mitochondria and cell research to measure respiration in various types of mitochondrial preparations and living cells combined with MultiSensor modules. Mitochondrial function and dysfunction have gained increasing interest, reflecting growing awareness of the fact that mitochondria play a pivotal role in human health and disease. HRR combines instrumental accuracy and reliability with the versatility of applicable protocols, allowing practically unlimited addition and combination of substrates, inhibitors, and uncouplers using the Oroboros O2k-technology. Substrate-uncoupler-inhibitor titration (SUIT) protocols allow the interrogation of numerous mitochondrial pathway and coupling states in a single respirometric assay. Mitochondrial respiratory pathways may be analyzed in detail to evaluate even minor alterations in respiratory coupling and pathway control patterns. The O2k-technology provides sole source instruments, with no other available instrument meeting its specifications for high-resolution respirometry. Technologically, HRR is based on the Oroboros O2k-technology, combining optimized chamber design, application of oxygen-tight materials, electrochemical sensors, Peltier-temperature control, and specially developed software features (DatLab) to obtain the unique sensitive and quantitative resolution of oxygen concentration and oxygen flux, with both, a closed-chamber or open-chamber mode of operation (TIP2k). Standardized calibration of the polarographic oxygen sensor (static sensor calibration), calibration of the sensor response time (dynamic sensor calibration), and evaluation of instrumental background oxygen flux (systemic flux compensation) provide the experimental basis for high accuracy of quantitative results and quality control in HRR. HRR can be extended for MultiSensor analysis by using the O2k-Fluo Smart-Module. Smart Fluo-Sensors are integrated into the O2k to measure simultaneously fluorometric signals using specific fluorophores. Potentiometric modules are available with ion-selective electrodes (pH, TPP⁺⁾. The PB-Module extends HRR to PhotoBiology with accurate control of the light intensity and measurement of photosynthesis. The O2k and the NextGen-O2k support all these O2k-Modules. The NextGen-O2k all-in-one, however, is unique in supporting Q-Redox and NADH-Redox Modules.
Holode		Small entetic units are counted into the reference system on a balance opposite to the experimental system with the large sample, which in balance contains as many abstract units as the count of entetic units in the reference system.
Homeothermy		Homeothermy is the stable regulation of body temperature in endotherms by metabolic heat production and control of heat exchange with the environment, or in ectotherms by behavioural means to select a stable thermal environment.
Hood 2019 Nutr Diabetes
Horseradish peroxidase	HRP	Horseradish peroxidase readily combines with hydrogen peroxide (H₂O₂) and the resultant [HRP-H₂O₂] complex can oxidize a wide variety of hydrogen donors.
Hydride	H^-	The hydride anion is the species H⁻.
Hydrogen	H₂	Molecular hydrogen H₂ is a constituent of the air with a volume fraction of 0.00005. It is a colorless and odorless gas with a molecular mass of 2.016. Its pharmacological potential and effects on mitochondrial metabolism are discussed in various publications without complete evidence on the underlying mechanisms.
Hydrogen ion	H⁺	The terms hydrogen ion H⁺ and proton, p or p⁺, are used synonymously in chemistry. A hydrogen ion is a positively charged molecule. In particle physics, however, a proton is a submolecular and subatomic particle with a positive electric charge. The H⁺ ion has no electrons and is a bare charge with only about 1/64 000 of the radius of a hydrogen atom. Free H⁺ is extremely reactive, with an extremely short lifetime in aqueous solutions. There H⁺ forms the hydronium ion H₃O⁺, which in turn is further solvated by water molecules in clusters such as H₅O₂⁺ and H₉O₄⁺. The transfer of H⁺ in an acid–base reaction is referred to as proton transfer. The acid is the H⁺ donor and the base is the H⁺ acceptor.
Hydrogen ion pump		Mitochondrial hydrogen ion pumps — frequently referred to as "proton pumps" — are large enzyme complexes (CI, CIII, CIV, ATP synthase) spanning the mt-inner membrane mtIM, partially encoded by mtDNA. CI, CIII and CIV are H⁺ pumps that drive hydrogen ions against the electrochemical protonmotive force pmF and thus generating the pmF, driven by electron transfer from reduced substrates to oxygen. In contrast, ATP synthase (also known as CV) is a H⁺ pump that utilizes the exergy of proton flow along the protonmotive force to drive phosphorylation of ADP to ATP.
Hydrogen peroxide	H₂O₂	Hydrogen peroxide, H₂O₂ or dihydrogen dioxide, is one of several reactive oxygen intermediates generally referred to as reactive oxygen species (ROS). It is formed in various enzyme-catalyzed reactions (e.g., superoxide dismutase) with the potential to damage cellular molecules and structures. H₂O₂ is dismutated by catalase to water and oxygen. H₂O₂ is produced as a signaling molecule in aerobic metabolism and passes membranes more easily compared to other ROS.
Hydrogen sulfide	H₂S	Hydrogen sulfide (H₂S) is involved in signaling and may have have further biological importance.
Hydrogenion flux	J_H+	Volume-specific hydrogenion flux or H⁺ flux is measured in a closed system as the time derivative of H⁺ concentration, expressed in units [pmol·s^-1·mL^-1]. H⁺ flux can be measured in an open system at steady state, when any acidification of the medium is compensated by external supply of an equivalent amount of base. The extracellular acidification rate (ECAR) is the change of pH in the incubation medium over time, which is zero at steady state. Volume-specific H⁺ flux is comparable to volume-specific oxygen flux [pmol·s^-1·mL^-1], which is the (negative) time derivative of oxygen concentration measured in a closed system, corrected for instrumental and chemical background. pH is the negative logarithm of hydrogen ion activity. Therefore, ECAR is of interest in relation to acidification issues in the incubation buffer or culture medium. The physiologically relevant metabolic H⁺ flux, however, must not be confused with ECAR.

Semantic search

Query log