Related Experiment Video
Updated: Mar 10, 2026
09:42
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
9.4K
Exact Product Formation Rates for Stochastic Enzyme Kinetics
1School of Biological Sciences, University of Edinburgh , Edinburgh EH8 9YL, U.K.
The Journal of Physical Chemistry. B
|December 14, 2016
Summary
This study uses the chemical master equation to model enzyme reaction rates without the substrate abundance assumption. Novel expressions reveal how substrate concentration and intrinsic noise affect enzyme kinetics, offering new insights into cellular biochemistry.
Area of Science:
- Biochemistry
- Chemical Kinetics
- Systems Biology
Background:
- Enzyme reaction rates are crucial for understanding biochemical processes.
- Classical models often assume substrate abundance, which is not applicable in cellular environments.
- Substrate concentration can be rate-limiting in cellular biochemistry.
Purpose of the Study:
- To derive expressions for enzyme reaction rates without the substrate abundance assumption.
- To investigate the impact of substrate concentration and intrinsic noise on enzyme kinetics.
- To provide a more accurate model for enzyme reactions in cellular contexts.
Main Methods:
- Utilized the chemical master equation to model enzyme kinetics.
- Derived expressions for instantaneous and time-averaged product formation rates.
- Analyzed various enzyme reaction mechanisms, including Michaelis-Menten reactions.
Main Results:
- Developed a logarithmically corrected Michaelis-Menten form for single-enzyme reactions.
- Demonstrated that intrinsic noise affects cooperativity and substrate inhibition.
- Showed that the initial rate of product formation is a sum of Michaelis-Menten equations for multi-molecule systems.
Conclusions:
- The chemical master equation provides a robust framework for studying enzyme kinetics beyond the substrate abundance assumption.
- Intrinsic noise plays a significant role in modulating enzyme behavior, impacting cooperative binding and substrate inhibition.
- The derived models offer a more realistic representation of enzyme reactions in cellular biochemistry.
Related Concept Videos
01:19Introduction to Enzyme Kinetics
35.6K
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...
35.6K
01:19Enzyme Kinetics
105.4K
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...
105.4K
01:07Catalytically Perfect Enzymes
5.3K
The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at high-speed. Their catalytic efficiency values range from 108-109 M-1s-1. These enzymes are also called 'diffusion-controlled' as the only rate-limiting step in the catalysis is that of the substrate diffusion into the active site. Examples include triose phosphate isomerase, fumarase, and superoxide dismutase.
Most enzymes...
Most enzymes...
5.3K
01:19Turnover Number and Catalytic Efficiency
22.0K
The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from 1 to 1000 molecules per second. Catalase has the known highest turnover number, capable of converting up to 2.8×106 molecules of hydrogen peroxide into water and oxygen per second. Lysozyme has the lowest known turnover number of half a molecule per second.
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion....
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion....
22.0K
01:15Fundamental Mathematical Principles in Pharmacokinetics: Rate and Order of Reaction
1.3K
In pharmacokinetics, the rates and order of reactions play a crucial role in understanding how the body processes drugs and help us comprehend drug absorption, distribution, metabolism, and elimination. A critical concept in pharmacokinetics is the rate constant, which quantifies the speed of a reaction. It provides valuable information about the kinetics of drug elimination. The rate constant allows us to determine the rate at which drugs are eliminated from the body.
Pharmacokinetic reactions...
Pharmacokinetic reactions...
1.3K
02:53Reaction Rate
69.9K
The rate of reaction is the change in the amount of a reactant or product per unit time. Reaction rates are therefore determined by measuring the time dependence of some property that can be related to reactant or product amounts. Rates of reactions that consume or produce gaseous substances, for example, are conveniently determined by measuring changes in volume or pressure.
The mathematical representation of the change in the concentration of reactants and products, over time, is the rate...
The mathematical representation of the change in the concentration of reactants and products, over time, is the rate...
69.9K