Molecular dynamics simulations have been used extensively to model the folding and unfolding of proteins. The rates of folding and unfolding should follow the Arrhenius equation over a limited range of temperatures. This study shows that molecular dynamic simulations of the unfolding of crambin between 500K and 560K do follow the Arrhenius equation. They also show that while there is a large am...

Picosecond studies of rhodopsin in low-temperature glasses have been carried out in order to observe directly the risetime of prelumirhodopsin, the first intermediate in the visual pathway. Only at 20 K or below can the risetime of this intermediate be resolved and even at 4 K it is astoundingly rapid, about 36 psec. An examination of the Arrhenius dependence on temperature of the rate of forma...

The Sf21 cell line is extensively used for virus research and producing heterologous recombinant proteins. To develop optimal strategies for minimizing cell injury due to intracellular ice formation and excessive volume shrinkage during cryopreservation, the fundamental transport properties including the osmotic inactive volume (Vb ), the hydraulic conductivity (Lp ), and the glycerol permeabil...

Careful analysis of the Arrhenius plot of the Na+,Mg2+-ATPase (ATP pyrophosphohydrolase, EC 3.6.1.8) activity in Acholeplasma laidlawii B membranes of varying fatty acid composition has been combined with differential thermal analysis of the membrane lipid phase transitions to evaluate the effects of membrane lipid properties on the enzyme activity. Our results indicate that the enzyme is activ...

We report the results of a fast thermal desorption spectroscopy study of the H/D isotopic exchange kinetics in a few micrometer thick, pure polycrystalline ice film and in ice films doped with HCl. Using the isotopic exchange reaction as a probe of molecular transport in ice, we were able to determine the effective water-self diffusion coefficients, Deff, in pure and doped polycrystalline ice a...

A recently developed atomistic method capable of calculating the fragile (non-Arrhenius) temperature behavior of highly viscous liquids is further tested by studying a model of SiO(2), a glass former well known for its Arrhenius temperature behavior (strong). The method predicts an Arrhenius temperature variation, in agreement with experiments, the origin of which is revealed by both quantitati...

Thermal inactivation of peroxidase (POD) in an extract of Picea omorika (Pancić) Purkyne needles initiated by heat treatment was studied. This is the first study of this kind on a conifer species. Non-linear regression analysis was applied on the inactivation rate data, combining Mitscherlich and Arrhenius equations, treating time and temperature simultaneously as explaining variables. We deter...

Conservation and cooking of foods can be used by students and instructors to demonstrate a fundamental relation of chemical kinetics, the Arrhenius equation. By plotting the logarithms of available conservation and cooking times versus the corresponding inverse temperatures, apparent activation energies for both the deterioration and the cooking of foods of various compositions can be obtained....

The flow behavior of a Ti-6Al-4V alloy has been investigated and modeled, with the aim exploring damage mechanism distortion sandwich structure during air cooling process after superplastic forming (SPF). selected temperature range was 930–700 °C, strain rates were 10?2, 10?3, 10?4/s. An Arrhenius model employed to describe yield stress at 0.1, simple generalized reduced gradient refinement app...

The widely used Arrhenius equation describes the kinetics of simple two-state reactions, with the implicit assumption of a single transition state with a well-defined activation energy barrier DeltaE, as the rate-limiting step. However, it has become increasingly clear that the saddle point of the free-energy surface in most reactions is populated by ensembles of conformations, leading to nonex...