scholarly journals Understanding the role of transport velocity in biomotor-powered microtubule spool assembly

RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 79143-79146 ◽  
Author(s):  
Amanda J. Tan ◽  
Dail E. Chapman ◽  
Linda S. Hirst ◽  
Jing Xu
Keyword(s):  
Steady State ◽  
Transport Velocity ◽  
Kinetics Of

We examined the role of transport velocity in the active assembly of microtubule spools. We found that transport velocity influences the kinetics of spool assembly, but not the steady-state properties of assembled spools.

On the role of transport in the combustion kinetics of a steady-state premixed laminar CO + H2 + O2 flame

1994 ◽  
Vol 26 (4) ◽  
pp. 437-453 ◽  
Author(s):  
Manoj K. Mishra ◽  
Richard Yetter ◽  
Yakir Reuven ◽  
Herschel Rabitz ◽  
Mitchell D. Smooke
Keyword(s):  
Steady State ◽  
Combustion Kinetics ◽  
Premixed Laminar ◽  
Kinetics Of

I. Intrazellulärer Transport von Zwischenprodukten der Photosynthese im Photosynthese-Gleichgewicht und im Dunkel-Licht-Dunkel-Wechsel

1967 ◽  
Vol 22 (11) ◽  
pp. 1189-1199 ◽  
Author(s):  
U. Heber ◽  
K. A. Santarius ◽  
M. A. Hudson ◽  
U. W. Hallier
Keyword(s):  
Steady State ◽  
Phosphate Esters ◽  
Dark Light ◽  
Regulation Of Metabolism ◽  
Large Fluctuations ◽  
Phosphoglyceric Acid ◽  
Intact Leaves ◽  
Sugar Phosphates ◽  
Kinetics Of

1. The distribution — before, during and after photosynthesis — of different phosphate esters in chloroplasts and cytoplasm of leaf cells of spinach and Elodea has been investigated. In steady state experiments intact leaves were fed, during illumination, with 14CO2. The kinetics of the distribution of labelled phosphate esters between chloroplasts and cytoplasm were determined. In further experiments with intact leaves fluctuations in the pool sizes of phosphate esters in chloroplasts and in the cytoplasm were recorded in the dark/light and the light/dark transient. Independent fluctuations served as an indication that little or no exchange between chloroplasts and cytoplasm takes place. Concomitant fluctuations suggest rapid exchange.2. Although labelling takes place in the chloroplasts, a number of labelled phosphorylated intermediates appear rapidly in the cytoplasm during steady state photosynthesis of intact leaves in the presence of 14CO2. This is particularly true for phosphoglyceric acid, glucose-6-phosphate, fructose-6-phosphate and fructose-1,6-diphosphate. On the other hand, labelled ribulosediphosphate, sedoheptulosediphosphate and sedoheptulosemonophosphate remain largely in the chloroplasts. This agrees with earlier work on the behaviour of phosphorylated intermediates during the induction period of photosynthesis.3. In the dark the level of the bulk of the sugar diphosphates is lower in the chloroplasts than in the cytoplasm of intact leaves. On illumination, a large accumulation occurs only in the chloroplasts. This behaviour suggests impermeability of the chloroplast membrane towards at least some of the sugar diphosphates. In contrast, concomitant large fluctuations in the levels of dihydroxyacetonephosphate and fructose-1,6-diphosphate have been observed during the transients from dark to light and vice versa in chloroplasts and cytoplasm alike indicating that at least one of these compounds functions as a transport metabolite. Changes in the concentrations of glucose-6-phosphate and fructose-6-phosphate were much smaller under the influence of light than those of other sugar phosphates.4. The results demonstrate the role of phosphorylated transport metabolites in carbon metabolism in chloroplasts and cytoplasm. Implications of these findings in relation to photosynthesis, respiration and the regulation of metabolism are discussed.

Thermodynamic and Kinetic Investigation of the Solvent Effect on the Oxidation of [Co(en)2SCH2COO]+ with S2O82- In Water-Methanol and Water-tert-Butyl Alcohol Mixtures

1993 ◽  
Vol 58 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko
Keyword(s):  
Transfer Functions ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Oxidation Of Co ◽  
Kinetics Of Oxidation ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Alcohol Mixtures ◽  
Kinetics Of

The kinetics of oxidation of [Co(en)2SCH2COO]+ with S2O82- was studied in water-methanol and water-tert-butyl alcohol mixtures. Changes in the reaction activation parameters ∆H≠ and ∆S≠ with varying concentration of the co-solvent depend on the kind of the latter, which points to a significant role of salvation effects. The solvation effect on the reaction is discussed based on a comparison of the transfer functions ∆Ht0, ∆St0 and ∆Gt0 for the initial and transition states with the changes in the activation parameters accompanying changes in the CO-solvent concentration. The transfer enthalpies of the reactant were obtained from calorimetric measurements.

Kinetic analysis of mechanism of intestinal Na+-dependent sugar transport

1985 ◽  
Vol 248 (5) ◽  
pp. C498-C509 ◽  
Author(s):  
D. Restrepo ◽  
G. A. Kimmich
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Sugar Transport ◽  
Enzyme Kinetic ◽  
Steady State Distribution ◽  
State Distribution ◽  
Least Squares Fit ◽  
Coupling Stoichiometry ◽  
Rate Limiting ◽  
Kinetics Of

Zero-trans kinetics of Na+-sugar cotransport were investigated. Sugar influx was measured at various sodium and sugar concentrations in K+-loaded cells treated with rotenone and valinomycin. Sugar influx follows Michaelis-Menten kinetics as a function of sugar concentration but not as a function of Na+ concentration. Nine models with 1:1 or 2:1 sodium:sugar stoichiometry were considered. The flux equations for these models were solved assuming steady-state distribution of carrier forms and that translocation across the membrane is rate limiting. Classical enzyme kinetic methods and a least-squares fit of flux equations to the experimental data were used to assess the fit of the different models. Four models can be discarded on this basis. Of the remaining models, we discard two on the basis of the trans sodium dependence and the coupling stoichiometry [G. A. Kimmich and J. Randles, Am. J. Physiol. 247 (Cell Physiol. 16): C74-C82, 1984]. The remaining models are terter ordered mechanisms with sodium debinding first at the trans side. If transfer across the membrane is rate limiting, the binding order can be determined to be sodium:sugar:sodium.

scholarly journals Association between perinatal factors, genetic susceptibility to obesity and age at adiposity rebound in children of the EDEN mother–child cohort

2021 ◽  
Author(s):  
Aminata Hallimat Cissé ◽  
Sandrine Lioret ◽  
Blandine de Lauzon-Guillain ◽  
Anne Forhan ◽  
Ken K. Ong ◽  
...  
Keyword(s):  
Weight Gain ◽  
Genetic Susceptibility ◽  
Gestational Weight Gain ◽  
Gestational Age ◽  
Obesity Risk ◽  
Perinatal Factors ◽  
Gestational Weight ◽  
Adiposity Rebound ◽  
Kinetics Of

Abstract Background Early adiposity rebound (AR) has been associated with increased risk of overweight or obesity in adulthood. However, little is known about early predictors of age at AR. We aimed to study the role of perinatal factors and genetic susceptibility to obesity in the kinetics of AR. Methods Body mass index (BMI) curves were modelled by using mixed-effects cubic models, and age at AR was estimated for 1415 children of the EDEN mother–child cohort study. A combined obesity risk-allele score was calculated from genotypes for 27 variants identified by genome-wide association studies of adult BMI. Perinatal factors of interest were maternal age at delivery, parental education, parental BMI, gestational weight gain, maternal smoking during pregnancy, and newborn characteristics (sex, prematurity, and birth weight). We used a hierarchical level approach with multivariable linear regression model to investigate the association between these factors, obesity risk-allele score, and age at AR. Results A higher genetic susceptibility to obesity score was associated with an earlier age at AR. At the most distal level of the hierarchical model, maternal and paternal educational levels were positively associated with age at AR. Children born to parents with higher BMI were more likely to exhibit earlier age at AR. In addition, higher gestational weight gain was related to earlier age at AR. For children born small for gestational age, the average age at AR was 88 [±39] days lower than for children born appropriate for gestational age and 91 [±56] days lower than for children born large for gestational age. Conclusion The timing of AR seems to be an early childhood manifestation of the genetic susceptibility to adult obesity. We further identified low birth weight and gestational weight gain as novel predictors of early AR, highlighting the role of the intrauterine environment in the kinetics of adiposity.

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