Enzymatic Reaction Kinetics

Study Notes

Enzymatic Reaction Kinetics

The Michaelis-Menten equation describes the relationship between the rate of an enzymatic reaction (v) and the substrate concentration ([S]).
Vmax represents the maximum velocity of the reaction, achieved when all enzyme active sites are saturated with substrate.
KM is the Michaelis constant, representing the substrate concentration at which the reaction rate is half of Vmax.
The Lineweaver-Burk plot (double reciprocal plot) is used to graphically determine Vmax and KM from experimental data.
Inhibitors can decrease the rate of enzymatic reactions by binding to the enzyme and interfering with its activity.
Competitive inhibitors bind to the active site of the enzyme, competing with the substrate.
Non-competitive inhibitors bind to a different site on the enzyme, changing its conformation and reducing its activity.
Ki is the dissociation constant of the enzyme-inhibitor complex, reflecting the affinity of the inhibitor for the enzyme.
The co-substrate plays a crucial role in enzymatic reactions alongside the main substrate.
NAD+ is a common co-substrate in dehydrogenase enzymes.
ATP acts as a co-substrate in kinase enzymes.
Enzymes do not affect the equilibrium constant of a reaction, they only accelerate the rate of reaching equilibrium.
Acetyl CoA is an important reactant in metabolic reactions that involve C-C bond formation.
Chymotrypsin is a protease enzyme with a catalytic triad consisting of Ser, His, and Asp residues.
Arrhenius equation describes the relationship between the rate constant (k) of a reaction and temperature (T).
The activation energy (Ea) is the minimum energy required for reactants to transition into products.
The pre-exponential factor (A) accounts for the frequency of collisions between reactant molecules.
KM is expressed in units of concentration, typically molar (M).
The equilibrium constant (K) is a ratio of product concentrations to reactant concentrations at equilibrium.
For a forward reaction with rate constant kf and a backward reaction with rate constant kb, the equilibrium constant K is calculated as K = kf/kb.