Related Experiment Video
Updated: Feb 19, 2026
09:42
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
9.4K
Thermodynamic Activity-Based Progress Curve Analysis in Enzyme Kinetics.
1Institute of Technical Biochemistry, University of Stuttgart, Allmandring 31, D-70569 Stuttgart, Germany.
Trends in Biotechnology
|November 7, 2017
Summary
Macrokinetic Michaelis-Menten models using thermodynamic activity offer enzyme kinetics insights by separating substrate-enzyme and substrate-solvent interactions. The study highlights potential pitfalls in parameter estimation from reaction progress curves.
Area of Science:
- Biochemistry
- Chemical Kinetics
- Thermodynamics
Background:
- Enzyme kinetics are crucial for understanding biological processes.
- Traditional models often overlook solvent effects on enzyme-substrate interactions.
- Thermodynamic activity offers a more comprehensive approach to modeling enzyme behavior.
Purpose of the Study:
- To explore macrokinetic Michaelis-Menten models incorporating thermodynamic activity.
- To elucidate the separation of substrate-enzyme and substrate-solvent interactions.
- To identify and discuss common pitfalls in kinetic parameter estimation.
Main Methods:
- Utilizing macrokinetic models based on thermodynamic activity.
- Estimating kinetic parameters from experimental enzyme-catalyzed reaction progress curves.
- Analyzing deviations between thermodynamic and concentration-based models.
Main Results:
- Thermodynamic activity models provide deeper insights into enzyme kinetics.
- Separation of substrate-enzyme and substrate-solvent interactions is achieved.
- Identified pitfalls include model deviations, product effects on activity, and product inhibition.
Conclusions:
- Macrokinetic models based on thermodynamic activity enhance understanding of enzyme kinetics.
- Careful consideration of substrate-solvent interactions and product effects is essential for accurate kinetic parameter estimation.
- Addressing identified pitfalls improves the reliability of enzyme kinetic studies.
Related Concept Videos
01:10Thermodynamics: Chemical Potential and Activity
1.9K
The effective concentration of a species in a solution can be expressed precisely in terms of its activity. Activity considers the effect of electrolytes present in the vicinity of the species of interest and depends on the ionic strength of the solution. The activity of a species is expressed as the product of molar concentration and the activity coefficient of the species.
The thermodynamic equilibrium constant is more accurately defined in terms of activity rather than concentration.
The thermodynamic equilibrium constant is more accurately defined in terms of activity rather than concentration.
1.9K
01:19Introduction to Enzyme Kinetics
34.2K
Enzyme kinetics studies the rates of biochemical reactions. Scientists monitor the reaction rates for a particular enzymatic reaction at various substrate concentrations. Additional trials with inhibitors or other molecules that affect the reaction rate may also be performed.
The experimenter can then plot the initial reaction rate or velocity (Vo) of a given trial against the substrate concentration ([S]) to obtain a graph of the reaction properties. For many enzymatic reactions involving a...
The experimenter can then plot the initial reaction rate or velocity (Vo) of a given trial against the substrate concentration ([S]) to obtain a graph of the reaction properties. For many enzymatic reactions involving a...
34.2K
01:24Thermodynamics: Activity Coefficient
3.1K
Activity is the measure of the effective concentration of the species in solution. It can be expressed as the product of the molar concentration of the species and its activity coefficient. The activity coefficient is a dimensionless quantity and depends on the total ionic strength of the solution.
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
3.1K
02:34Arrhenius Plots
47.5K
The Arrhenius equation relates the activation energy and the rate constant, k, for chemical reactions. In the Arrhenius equation, k = Ae−Ea/RT, R is the ideal gas constant, which has a value of 8.314 J/mol·K, T is the temperature on the kelvin scale, Ea is the activation energy in J/mole, e is the constant 2.7183, and A is a constant called the frequency factor, which is related to the frequency of collisions and the orientation of the reacting molecules.
The Arrhenius equation can be used...
The Arrhenius equation can be used...
47.5K
01:19Enzyme Kinetics
104.6K
Enzymes speed up reactions by lowering the activation energy of the reactants. The speed at which the enzyme turns reactants into products is called the rate of reaction. Several factors impact the rate of reaction, including the number of available reactants. Enzyme kinetics is the study of how an enzyme changes the rate of a reaction.
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
104.6K
02:55Temperature Dependence on Reaction Rate
89.4K
The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
89.4K