Enzymes Flashcards
(25 cards)
What is the function of beta galactosidase
to hydrolyse lactose (products are galactose and glucose) and other galactosides
Michaelis - menten equation
v = vmax ([s]/km+[s])
What is vmax
the maximal velocity
What is km
the substrate concentration that gives a velocity of half of vmax
Kcat formula
(K2+Kcat)/K1
What is the rate of formation proportional to
the concentration of the enzyme substrate complex
Rate of change[P] formula
Kcat[ES]
Vmax formula
Kcat x [Etot]
What is vmax directly proportional to
the enzyme concentration
V=kcat[Etot] is dependent on what
has linear dependence on enzyme concentration
[S]/(Km+[S]) has dependence on what
hyperbolic dependence on substrate concentration
specifity constant
Kcat/Km
Features of a good enzyme
High Kcat, low Km, Kcat/km is high
What is a lineweaver-burke plot
1/v plotted against 1/[S]
What does the x and y intercept show on a lineweaver-burke plot
X = -1/km. Y = 1/Vmax
Lineweaver-Burke plot equation
1/v = Km/vmax 1/[S] + 1/Vmax
What is the enzyme transition state
highest energy state in a reaction, the binding of a substrate stabilise them and lowers the energy barrier
What is reversible inhibition
competitive inhibition - competing to bind to the active site so the substrate can’t
Velocity with inhibitor equation
V = Vmax ([s]/(km(1+([I]/Ki)) + [S])
What is kmapp formula
km (1+([I]/Ki))
What is Km
the real value for the interaction of the enzyme and substrate
What is km apparent
what it seems to have chnaged during the experiment
What is a good Ki value
low - less inhibitor needed for desired effect
