Reaction rate defined

Alternatively, we may assume that there exists some (but possibly limited) knowledge about the typical concentrations involved. For each metabolite, we can then specify an interval St < S1- <. S ) that defines a physiologically feasible range of the respective concentration. Furthermore, the steady-state flux vector v° is subject to the mass-balance constraint Nv° = 0, leaving only r — rank(N) independent reaction rates. Again, an interval v(. < v9 < v+ can be specified for all independent reaction rates, defining a physiologically admissible flux space. 

This rate coefficient corresponds to the reaction rate rp namely, to the reaction rate defined per active site. This rate coefficient for a specific reaction and a fixed catalytic agent and temperature can be considered constant. 

The difference between the potential applied and the reversible potential for a reaction is known as the overpotential. It represents the driving force for the kinetics of the reaction. Anodic overpotentials are associated with oxidation reactions, and cathodic overpotentials are associated with reduction reactions. The relationship between the overpotential and the reaction rate defines the kinetics. Mathematical relationships exist for many instances, but in corrosion situations, the data are generally experimentally derived. 

In a unimolecular elementary step, a reactant molecule undergoes rearrangement or break-up. The reaction is a matter of inherent probability. At a given temperature, each reactant molecule has the same probability to react (however, see a qualifying comment at the end of this section). Accordingly, the reaction rate—defined as the number of molecules converted per unit volume and unit time—is proportional to the number of reactant molecules per unit volume at the respective time, that is, to the local and momentary reactant concentration. The proportionality factor reflecting the probability of the event is the rate coefficient, denoted k. 

As before, it is assumed that the potential V is characterized by a reactant region, a potential well, separated from the product region by a high potential barrier, see Fig. 14.2. We want to calculate the reaction rate, defined within this model as the rate at which the particle escapes from this well. 

For phosphofructokinase in the liver, ATP, ADP, and citrate are effectors of the reaction rate. Define what type of effectors they are, based on the information given in the reaction scheme shown in Fig. 5-33. 

The reaction rate, defined as dx/dt, is proportional to the quantity of reactant that is available for reaction. For solution reactions, the reaction volume V should be included in the equation. Equation (25) describes a reaction where (A) reacts to form (B) in a single mechanism ... 

The production rate in a system is defined as the number of moles of product, or converted reactant to main product, per unit of volume and time. It is an overall average rate, different from reaction rate defined previously, which is local. 

Activity is a measure of the rate at which the catalyst causes the chemical reaction to arrive at equilibrium. In terms of kinetics, the reaction rate defines catalyst activity as the quantity of reactant consumed per unit time per unit volume or mass of catalyst ... 

SO that the initial reaction rate defined by eq. (14.5), is expressed as... 

To quantify the speed at which a reaction occurs, it is necessary to determine the reaction rate defined as the change in the concentration of reactants or products over a period of time. 

The average molecular weight of the cychc polymers depends on the kinetic scenario. For a short discussion of the correlation between ring size and kinetic course of the entire polymerization process, the four reaction rates defined in Eqs. (15.1)-(15.4) will be helpful. 

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