Enzyme Kinetics

Question 1

Enzyme Kinetics

Answer 1

the study of the reaction rates of enzyme catalyzed reactions

Question 2

What is the rate of a reaction influenced by?

Answer 2

• environmental conditions like pH and temp
• concentrations of enzymes, substrates, and products
• effectors like activators and inhibitors

Question 3

pH higher or lower than optimum pH can

Answer 3

cause the enzyme to become inactive

Question 4

If pH is too extreme, it can

Answer 4

destroy the enzymes

Question 5

Enzyme activity ______ as temperature is higher than the optimal temp, so the enzyme is ______

Answer 5

declines, denatured

Question 6

Increasing enzyme concentration

Answer 6

increases enzyme activity

Question 7

Increasing substrate concentration increases

Answer 7

the reaction rate until the enzyme is saturated, then the reaction rate becomes constant

Question 8

If an enzyme is saturated then there is

Answer 8

far more substrate than it can deal with

Question 9

Km is called the

Answer 9

michealis-menten constant

Question 10

Km is the substrate concentration at

Answer 10

half Vmax

Question 11

Km is _______ proportional to affinity of enzyme for substrate

Answer 11

inversely

Question 12

High Km means

Low Km means

Answer 12

low affinity towards substrate

high affinity towards substrate

Question 13

Michaelis-Menten Equation

Answer 13

used to caqlculate reaction rates

Vi= Vmax[S]/Km + [S]

Question 14

Vi=
[S]=
Vmax=
Km=

Answer 14

initial velocity (moles/time)
substrate concentration (molar)
maximum velocity
substrate concentration when Vi is 1/2 Vmax

Question 15

Effecters

Answer 15

a substance that can binds to an enzyme and affects the enzyme activity is called an effecter

Question 16

Activators

Answer 16

positive effectors

Question 17

Inhibitors

Answer 17

negative effectors

Question 18

Inhibitors are

Answer 18

molecules that bind to an enzyme and reduce enzyme activity

Question 19

Inhibitors are classified into

Answer 19

irreversible inhibitors

reversible inhibitors

Question 20

Irreversible inhibitors

Answer 20

bind covalently (strongly) to the enzyme

Question 21

Reversible inhibitors

Answer 21

bind non-covalently (weakly) to the enzyme

Question 22

Irreversible Inhibitors are involved in

Answer 22

the binding of the inhibitor to the active site which blocks the reaction, the enzyme is damaged permanently

Question 23

Ihibitors are often used as ……….. but they can also act as ……….

Answer 23

drugs, poisons

Question 24

Irreversible inhibitors include

Answer 24

arsenic
snake venom
nerve gas

Question 25

Reversible inhibitors can be

Answer 25

competitive inhibitors

noncompetitive inhibitors

Question 26

Competitive inhibitors

Answer 26

• have a structure like a substrate
• binds to active site of the enzyme
• prevents substrate from binding
• can be released by increasing substrate concentration

Question 27

Noncompetitive Inhibitors

Answer 27

• don’t have a structure like a substrate
• bind to the enzyme but not the active site
• change the shape of enzymes and active sites
• substrates can’t fit altered active site
• no reaction occurs
• effect is not reversed by adding substrates