Enzyme kinetics seeks to determine the initial and maximal reaction velocity that enzymes can

attain and the binding affinities for substrates and inhibitors

Michaelis-Menten equation has a ______line on a graph

non-linear

Bisubstrate reactions can occur by _____or______mechanisms or by a _______mechanism

ordered, random-sequential, Ping-pong

1st order reactions display a linear plot of the

substrate or product concentration, as a function of time

Rate law is the mathematical relationship

between the reaction rate or velocity, and concentration of reactions (linear)

The amount of A consumed per unit of time

rate, or velocity

Formula for rate law

v=k[A]^{number in front of letter}

Michaelis-Menten formula:

v_o=V_max[S]/ K_m+[S]

Vo is equal to

the slope

At low [S], the rate is proportional

as in a first-order reaction

At high [S], the enzyme reaction approaches

zero-order kinetics :V_o=V_max

Rate of formation of ES is _____, while rate of dissociation is ___.

Rate of product formation is ____

k₁, k_-1, k₂

Catalysis is limiting, because the rate is independent of [S](E is saturated

0^th order (when K_mis less than)

Rate is dependent on [S], [S] is limiting

1^st order (when K_m is greater than)

When above K_m, it starts to

plateau due to saturation increasing

V_max=k₂[E_T]

K_m=(k_-1+k₂)/k₁

Small K_m means

little dissociation (10^-6)

Larger K_m means

lots of dissociation (10^-2)

K_cat, the turnover number, is the number of

substrate molecules converted to product per enzyme molecules, per unit of time, when E is saturated with substrate

Catalytic efficiency formula:

k_cat/K_m

k_cat/K_m is approaching

1.0x10⁹

At temperatures are above 50^o to 60^oC,

enzymes typically decline in activity

The two classes of single-displacement:

random and ordered

Random single displacement where either

substrate may bind first, followed by the other substrate

Ordered single displacement where a

leading substrate binds first, followed by the other substrate

Double displacement (Ping-Pong) reactions

involves a covalent intermediate

In single displacement, high concentrations the

y-intercept is lower

Random, single-displacement reaction is formed rapidly and reversibly when

enzyme is added to a reaction mixture containing A,B,P, and Q

Ordered, single-displacement reaction leading substrate (A) must

bind first, followed by B. And for the products, P and Q

Double-displacement has a formation

of a covalently modified enzyme intermediate, E'

Reversible inhibitor may bind

at the active site or at some other site

Four types of reversible enzyme inhibitors:

-competitive

-noncompetitive

-mixed noncompetitive

-uncompetitive

Competitive inhibition

only time where inhibitor can be competed by the substrates

Increases the apparent K_m but

no effect on V_max

Noncompetitive inhibitor

decreases Vmax with no change in K_m

Mixed noncompetitive alters

both Km and Vmax

Uncompetitive inhibition alters

both Km and Vmax but with same slope Km/Vmax

Uncompetetive inhibition only observed

in enzyme having two or more substrates

What type of reversible inhibitor is this?

Competitive Inhibition

Competitive inhibition______apparent K_m but______on Vmax

increases, no effect

What type of reversible inhibitor is this?

Pure noncompetitive inhibition

Pure noncompetitive inhibition____Vmax with ____in Km

decreases, no change

What type of reversible inhibitor is this?

Mixed noncompetitive inhibition

Mixed noncompetitive inhibition alters Km and Vmax by _____

decreasing

What type of reversible inhibitor is this?

Uncompetitive inhibition

Uncompetitive inhibition alters both Km and Vmax but have ______

the same slope, Km/Vmax