(n.) A certain property of a body, expressed as a measurable quantity, such that when there is no communication of heat the quantity remains constant, but when heat enters or leaves the body the quantity increases or diminishes. If a small amount, h, of heat enters the body when its temperature is t in the thermodynamic scale the entropy of the body is increased by h / t. The entropy is regarded as measured from some standard temperature and pressure. Sometimes called the thermodynamic function.
Example Sentences:
(1) This formalism allows resolution of the intrinsic protein folding-unfolding parameters (enthalpy, entropy, and heat capacity changes) as well as the ligand interaction parameters (binding stoichiometry, enthalpy, entropy, and heat capacity changes).
(2) Dictated by underlying physicochemical constraints, deceived at times by the lulling tones of the siren entropy, and constantly vulnerable to the vagaries of other more pervasive forms of biological networking and information transfer encoded in the genes of virus and invading microorganisms, protein biorecognition in higher life forms, and particularly in mammals, represents the finely tuned molecular avenues for the genome to transfer its information to the next generation.
(3) The Skilling maximum entropy method (MEM) algorithm is applied to in vivo spectra and provides an estimate of the spectrum that is operator-independent, although at the expense of some negative bias.
(4) The changes in E degrees' and the standard entropy (delta S degrees') and enthalpy (delta H degrees') of reduction in the mutant proteins were determined relative to values for wild type; the change in E degrees' at 25 degrees C was about -200 millivolts for the Glu and Asp mutants, and about -80 millivolts for the Asn mutant.
(5) It is shown that the invariant integral, viz., the Kolmogorov second entropy, is eminently suited to characterize EEG quantitatively.
(6) The thermodynamic quantities of change in free energy (delta G degree'), change in enthalpy (delta H degree') and change in entropy (delta S degree') were determined for the interaction of norepinephrine with the alpha-1 adrenoceptor of vascular smooth muscle.
(7) This paper is concerned with the connection between two classes of population variables: measures of population growth rate--the Malthusian parameter, the net reproduction rate, the gross reproduction rate, and the mean life expectancy; and measures of demographic heterogeneity--population entropy.
(8) Recent studies from this laboratory reveal distinct differences in the thermodynamic binding mechanisms between m-AMSA and o-AMSA (Wadkins & Graves, 1989), with the m-AMSA-DNA interaction being an enthalpy-driven process while the binding of o-AMSA to DNA is characterized by more positive entropy values.
(9) Such replacements are presumed to restrict the degrees of freedom of the unfolded protein and so decrease the entropy of unfolding [B. W. Matthews, H. Nicholson, and W. J. Becktel (1987) Proceedings of the National Academy of Science USA Vol.
(10) The overall enthalpy change is negative and the overall entropy change is positive for the simultaneous binding of AMP-PNP and L-glutamate or of AMP-PNP and L-Met-(S)-sulfoximine to the enzyme.
(11) The part of entropy depending on the number of elements of the system (cells, individuals, etc.)
(12) 2 orders of magnitude higher than that of free calmodulin; the latter is even more entropy driven (delta H0 = 7.2 kJ X site-1; delta S0 = 158 J X K-1 X site-1) than binding to free calmodulin (delta H0 = 4.7 kJ X site-1; delta S0 = 112 J X K-1 X site-1), thus underlining the importance of hydrophobic forces in the free energy coupling involved in the ternary complex.
(13) Thus, Ca2+ binding to the Ca2+-Mg2+ sites is driven by both enthalpy and entropy and the lower Ca2+ affinity for sites 3 and 4 is reflected in the lower entropy of Ca2+-binding.
(14) This paper presents a unified account of the properties of the measures, Malthusian parameter and entropy in predicting evolutionary change in populations of macromolecules, cells and individuals.
(15) The model stresses that solutes do not act at a single site, but on both states in an equilibrium, and that the perturbation is determined by the difference in entropy.
(16) The "entropy potential" of the membrane may have its molecular origin in the excitation of the hydrocarbon chains to a more disordered configuration and may play a more important role in membrane partition equilibria than the classical hydrophobic effect.
(17) The entropy of activation of kcat for the human enzyme was further decomposed into partially compensating electrostatic(es) (delta S*es = +15.1 cal mol-1 K-1) and nonelectrostatic(nes) (delta S*nes = -19.1 cal mol-1 K-1) terms.
(18) Basic free energy level differences are related to the first-order rate constants for transitions between states while gross free energy differences, along with the corresponding fluxes, determine the rate of entropy production in the system.
(19) Their high-affinity binding component was entropy driven at 2 degrees C and became enthalpy driven when the incubation temperature was increased.
(20) As far as information in nervous systems is connected with an element of energy normalization that is much greater than the scales of molecular energy of single atoms, physical and information self-organization can simultaneously either correlate or be sufficiently independent, because entropy corresponds to statically unstable point, with its output being natural in different ways.
Thermodynamics
Definition:
(n.) The science which treats of the mechanical action or relations of heat.
Example Sentences:
(1) From the previously observed results of preferential interactions for salting-out salts with proteins, it was shown that the free energy of the protein is increased by addition of the salts and this unfavorable free energy is smaller for the proteins bound to the columns because of their smaller surface area exposed to solvent; i.e., the bound form of the proteins is thermodynamically more stable.
(2) The viscosimetric and kinetic results are compared with the thermodynamic results obtained from the temperature dependence of the binding constants.
(3) The hypothesis that opiate agonism requires an N substituent in the axial position does not appear to be consistent with the increased potency of beta isomers in which axial N substituents are thermodynamically more unstable.
(4) Cleavage intensities were found to change with time in a manner that depended both on the site and on the drug, suggesting that topoisomerase II can move along the DNA from a kinetically preferred site to a thermodynamically preferred site.
(5) While the thermodynamics for (rGCGAGCG)2 and (rGCAGGCG)2 are similar, CD and the imino region of the proton NMR spectra indicate their structures are different.
(6) The complexes produced by both inhibitors are similar chemically since the thermodynamic parameters for activation to regenerate active enzyme are essentially identical.
(7) The thermodynamic activation energy of this reaction is 67.8 kcal mol-1.
(8) This is consistent with their thermodynamic and kinetic properties, since the H3O+ is often different from the Li+ in several orders of magnitude.
(9) Bounded, bulk, and perfusion-diffusion models are described in supersaturation, statistical, and thermodynamic frameworks.
(10) The effect of changes in the thermodynamic parameters on the equilibrium ensemble provides a further sensitivity check to the predictions.
(11) This is in keeping with thermodynamic principles which apply to chemical and biochemical reactions.
(12) The thermodynamics of this self-association have been evaluated by studying the temperature- and concentration-dependence of the mean residue ellipticity at 220 nm.
(13) This would allow the thermodynamic description of the role of proton translocation as that of a modificatory force of the structural parameters of proteins.
(14) The extrapolated aqueous solubility values in the absence of povidone were obtained as a function of temperature and were utilized to obtain thermodynamic parameters.
(15) Analysis of the thermodynamic parameters for the binding of 18 haptens forms the basis for proposing a model of the binding site of MOPC-104E.
(16) The relationships between thermodynamic quantities in a quaternary system of electrolytes are discussed in Appendix 2.
(17) The key assumptions are (1) that the target site is in the lower epidermis (basal layer) or in the dermis, and (2) that it is the thermodynamic activity (i.e., the free drug concentration, C*, of the active drug species) at the target site that is the true correlate of drug effectiveness.
(18) They also provide electronic and thermodynamic data that are not available from x-ray crystallographic data.
(19) Determination of the thermodynamic parameters from the calorimetric data has required the development of an analytical formalism that explicitly includes the thermodynamics as well as the kinetics of the transition.
(20) Thermodynamics of the enzyme-catalyzed (alkaline phosphatase, EC 3.1.3.1) hydrolysis of glucose 6-phosphate, mannose 6-phosphate, fructose 6-phosphate, ribose 5-phosphate, and ribulose 5-phosphate have been investigated using microcalorimetry and, for the hydrolysis of fructose 6-phosphate, chemical equilibrium measurements.