Related Experiment Video
Updated: Aug 9, 2026

Hot Biological Catalysis: Isothermal Titration Calorimetry to Characterize Enzymatic Reactions
Published on: April 4, 2014
Abstract:
The principle of Dixon (1965) has been extended to give rapid graphical methods for determining enzyme constants for substrates (K(m)) and inhibitors (K(i)). It does away with the sometimes questionable assumption that the amounts of substrate or inhibitor bound by the enzyme are negligible in comparison with the total amount added, and is therefore valid even for cases of high affinity, where the usual methods fail. Besides doing away with the need for calculation, it enables the concentrations of the various components of the system to be read off directly for any point of the velocity curve.
Related Concept Videos
Determining Order of Reaction
Calculating the Equilibrium Constant
For example, gaseous nitrogen dioxide forms dinitrogen tetroxide according to this equation:
The Equilibrium Binding Constant and Binding Strength
Introduction to Enzyme Kinetics
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...
Nonlinear Pharmacokinetics: Michaelis-Menten Equation
Vmax represents the maximum achievable process rate, while KM, known as the Michaelis constant, signifies the drug concentration at which the process rate reaches half its maximum. This relationship between Vmax, KM, and Cp gives rise to three distinct...
Determination of Michaelis Constant and Maximum Elimination Rate
These parameters can be estimated by analyzing plasma concentration data post-drug administration. A notable example of this application is phenytoin, a drug with capacity-limited kinetics. It's recommended that phenytoin should be administered at two...

