kinetics

Question 1

3 kinetic trends possible

Answer 1

linear

hyperbolic

sigmoidal

Question 2

first order kinetics:

equation

graph

Answer 2

v = k[S]¹ = k[S]

ln [S] / time

down right slope

Question 3

second order kinetics:

equation

graph

Answer 3

equation: k[S]² or k[S_A] [S_B]
graph: 1/[S] / time ; up-right slope

Question 4

zero order kinetics:

equation:

graph:

Answer 4

equation: v = k[S]⁰ = 0
graph: [S] / time ; down-right slope

Question 5

zero order kinetics:

substrate-independent interpretations

Answer 5

unimolecular reaction (not making/breaking bonds - something internal is changing) ; or don’t need an enzyme (uncatalyzed reaction)

enzyme is saturated

Question 6

rate constant of substrate to products

Answer 6

k₁

Question 7

rate constant of products –> substrates

Answer 7

k_-1

Question 8

reversible reaction rate equation

Answer 8

v = k₁[S]ⁿ - k_-1[P]^m

Question 9

equilibrium reaction rate equation

Answer 9

k₁[S] = k_-1 [P]

Question 10

K_A

Answer 10

[P] / [S] or k₁ / k_-1

association constant (makes P)

Question 11

K_D

Answer 11

[S] / [P] = k_-1 / k₁ = 1 / K_A

dissocation constant

Question 12

michaelis-menton enzymes follow what order kinetics

Answer 12

first

Question 13

michaelis-menton kinetics model

Answer 13

E + S <– k_-1 k₁ –> E * S – k₂ –> E + P

Question 14

Km

Answer 14

michaelis constant

[S] where reaction rate is half maximal OR half of the active sites are full

Question 15

v_max

Answer 15

maximum velocity

maximum rate possible for a given [enzyme]

Question 16

k_cat

Answer 16

turnover number

number of substrate molecules converted per active site per time (first order rate constant)

Question 17

K_s

Answer 17

a dissociation constant for substrate binding

Question 18

k_cat / K_m

Answer 18

specificity constant

measure of enzyme performance by predicting the fate of E * S

(predicting if the E*S complex fall apart to substrate or fall apart to products)

Question 19

first assumption of michaelis-menton equation

problems with first assumption

Answer 19

assume that binding of the substrate is at equilibirum

Problem: cannot measure [E] (free enzyme) but we know how much enzyme we added

Question 20

second assumption of michaelis-menten equations

problems associated with second assumption

Answer 20

• when [S] >> [E] , delta S ~ 0
• formation of the E *S complex occurs at the same rate as its loss
• problem: cannot measure [E *S]

Question 21

Michaelis-Menten Equation

Answer 21

v₀ = v_max [S] / K_m + [S]

Question 22

v_max is reached when the enzyme is

Answer 22

fully saturated

Question 23

laboratory conditions to remember

1. [S] << K_m
2. [S] = K_m
3. [S] >> K_m​

Answer 23

1. v₀ = (v_max / K_m ) [S}
2. v₀ = v_max / 2
3. V₀ = v_max

Question 24

1. a good enzyme would have k_cat _____ k_-1 and k_cat / k_m ~ _____
2. a poor enzyme would have k_cat _____ k_-1 and k_cat / k_m ~ _____

Answer 24

1. greater than and k₁
2. less than and 1 / km

Question 25

k_cat is roughly equal to

Answer 25

k₂

Question 26

multiple binding site enzymes can follow michaelis-menten kinetics as long as they are

Answer 26

noncooperative

Question 27

double reciprocal plot

Answer 27

lineweaver-burk plot

Question 28

slope of lineweaver-burk plot

Answer 28

K_m / V_max

Question 29

y intercept of lineweaver-burk plot

Answer 29

1 / v_max

Question 30

x-intercept of lineweaver-burk plot

Answer 30

-1 / K_M

Question 31

reversible inhibitors

Answer 31

use noncovalent interactions to bind

result in one of the following types of inhibition: competitive, noncompetitive, or uncompetitive

noncompetitive and uncompetitive inhibitors are allosteric

Question 32

competitive inhibiton graph

Answer 32

same y-intercept, different x-intercept

Question 33

competitive inhibition:

v_max is ______

K_m is ______

Answer 33

constant

variable

Question 34

noncompetitive inhibition graph

Answer 34

different y-intercept, and same x-intercept

Question 35

noncompetitive inhibition:

v_max is ______

K_m is ______

Answer 35

variable

constant

Question 36

uncompetitive inhibition graph

Answer 36

y-intercept is different, and x-intercept is different

Question 37

uncompetitive inhibition:

v_max is ______

K_m is ______

Answer 37

variable

variable

Question 38

irreversible inhibitors inactivte enzymes: Group-specific

What does it do:

specificity for active site:

Answer 38

targets a specific amino acid

low

Question 39

irreversible inhibitors inactivate enzymes: substrate analogs

what it does:

specificity for active site:

Answer 39

substrate mimic, modifies enzyme

high

Question 40

irreversible inhibitors inactivate enzymes: suicide inhibitors

what it does:

specificity for active site:

Answer 40

modified substrate so it is unable to form products

very high