Michaelis Menten Kinetics Flashcards
Why is kinetics needed
Draw a Michaelis menten plot
What does the Michaelis menten equation assume
Also assumes that the reverse reaction( [ES]→ [E]+[S] (k-1) ) can be neglected
What is the expression for the disocciation constant
Recall the Michaelis menten equation
derive the Michaelis menten equation for initial velocity from the expression for the dissociation constant
what is the steady state assumption and draw the graph for it *
intermediate species in a reaction mechanism remains constant over the time course of the reaction, even though the reactants and products are changing. This means that the rate of formation of the intermediate is equal to the rate of its consumption
Intermediate = ES
recall the equation for the Michaelis menten constant involving rate constants
how do you find initial velocity of a reaction using the Michaelis menten constant
Explain what the Michaelis menten equation shows and how Vmax and Km are obtained from a Michaelis menten plot
What does Km tell you
The affinity of the enzyme for the substrate
What does it mean if [Substrate]<Km
What does it mean if [Substrate]>Km
What are the units of Km and velocity
What does it mean if an enzyme has a low Km
What factors affect Km
Write an expression relating Km and Ks
What is Km a measure of
What does a high Km mean
How does Km affect an individuals susceptibility to alcohol
What is kcat
How do you calculate initial velocity using kcat and Km
What is kcat/Km used to measure
The greater the kcat/Km value, the more efficient the enzyme
What are the uses of kcat/Km
What is a catalytically perfect enzyme
Is when k2»k1
This means when the formation of [P] from the ES complex is fast compared to breakdown of ES complex back to enzyme and substrate
What is a catalytically perfect enzyme limited by
How do enzymes achieve catalytic perfection
What does Michaelis- menten kinetics assume
What does a Michaelis menten plot show
What is the equation that is plotted on a lineweaver - burk plot
Draw an example of a lineweaver - burk plot and recall the information you can obtain from it
What are the disadvantages of using the lineweaver - burk plot to measure kinetic parameters
Recall the equation used to produce a hofstee - eadie plot
What information can you obtain from a hofstee -eadie plot and what is the disadvantage of using this plot to obtain kenetic parameters
What equation is used to plot a Hanes - Woolf plot
Draw an example of a Hanes - Woolf plot and what you can obtain from it
Why is the hanes-woolf plot the most accurate out of the other plots discussed
What’s an equation that can be used to calculate Vmax from kcat and total conc. of enzyme
What is the principle of Michaelis- menten kinetics
Until the enzyme is fully saturated
What is the modified version of the Michaelis-menten equation that includes k-1 (the backwards reaction)
This treats ES as an intermediate
What is the equation for the haldane relationship
Km s and Km p are the Michaelis constants for the substrate and product, respectively.
Vmax f and Vmax r are the maximum velocities/ rate for the forward and backward reactions respectively
What does the haldane relationship tell you
At equilibrium v=0
What is the effect of pH on enzymes
At acidic, basic and optimum pH what are the charges of the residues on the substrate and the active site
What are lonization constants used for*
Ionization constants are used to describe the extent to which a compound, typically an acid or base, dissociates or ionizes in a solvent, usually water
What is the effect of temperature on enzymes
What are bisubstrate reactions
How are substrates characterised using cleland nomenclature
What is a sequential reaction
What is a ping-pong reaction
What are ordered and random reactions
Which enzyme doesn’t follow Michaelis - menten kinetics and why
