(LEC) Enzyme Kinetics

Question 1

What theory:

Enzyme + Substrate -> Enzymes-Substrate Complex -> Product + Enzyme

Answer 1

Michaelis-Menten Theory

Question 2

Formulated the Michaelis-Menten Theory

Answer 2

Leonor Michaelis & Maud Menten

Question 3

Maximum velocity or rate at which the enzyme catalyzed a reaction

Answer 3

Vmax

Question 4

Concentration of substrates when the reaction reaches half of Vmax

Answer 4

Km

Question 5

Measures how easily the enzyme can be saturated by the substrate

Answer 5

Km

Question 6

High Km = ?

Answer 6

High Substrate Concentration

Question 7

Low Km = ?

Answer 7

Low Substrate Concentration

Question 8

A double-reciprocal plot of the Michaelis-Menten constant which yields a straight line

Answer 8

Lineweaver-Burk Plot

Question 9

Formulated Lock & Key Theory

Answer 9

Emil Fischer

Question 10

Binding of a substrate or some other molecule to an enzyme causing a change in the shape of the enzyme resulting in enhancement or inhibition of the enzyme’s activity

Answer 10

Induced Fit Theory

Question 11

Factors that influence enzymatic reaction (7)

Answer 11

1. Substrate Concentration
2. Enzyme Concentration
3. pH
4. Temperature
5. Cofactors
6. Activators
7. Inhibitors

Question 12

Reaction rate is directly proportional to the concentration of ONE of the reactants

Answer 12

First-Order Reaction

Question 13

Reaction is directly proportional to the concentration of TWO reactants

Answer 13

Second-Order reaction

Question 14

Reaction rate is independent to the concentration of the reactants

Answer 14

Zero-Order reaction

Question 15

Ideal pH for Enzyme Reaction

Answer 15

pH 7.0 - 8.0

Question 16

Ideal Temperature for Enzyme Reaction

Answer 16

37 C

Question 17

Temperature of Denaturation

Answer 17

40-50 C

Question 18

CK denatures at what Temp

Answer 18

37 C

Question 19

Amylase denatures at what Temp

Answer 19

45 C

Question 20

3 types of Inhibitors

Answer 20

1. Competitive
2. Noncompetitive
3. Uncompetitive

Question 21

Inhibitor of Xanthine oxidase

Answer 21

Allopurinol

Question 22

Inhibitor of Cyclooxidase

Answer 22

Aspirin

Question 23

Inhibitor of Thymidylate synthetase

Answer 23

5-Fluorouracil

Question 24

Inhibitor of Lavastatin

Answer 24

HMG-CoA Reductase

Question 25

Inhibitor of Pargyline

Answer 25

Monoamine Oxidase

Question 26

Inhibitor of Penicilin

Answer 26

Transpeptidase

Question 27

Enzymatic Assays:

Enzymatic reaction of interest is paired with a second enzymatic reaction which can be conveniently and easily measured

Answer 27

Coupled-Enzyme Assay

Question 28

Convenient reagent for coupled-enzyme assay

Answer 28

NAD / NAD+ (If neither are coenzymes in the reaction)

Question 29

Enzymatic Assays:

Reactants are combined and proceeds for a designated time

Answer 29

Fixed-Time Method (End-Point)

Question 30

Enzymatic Assays:

Multiple measurements, usually of absorbance change, are made during this reaction at specific time intervals usually every 30s, 60, or continuous-recording spectrophotometer

Answer 30

Continuous-Monitoring Method (Kinetic Assay)

Question 31

Unit for amount of enzyme that will catalyze the reaction of 1 micromole of substrate per minute under specific conditions

Answer 31

International Unit (IU)

Question 32

Unit for enzyme concentration

Answer 32

International Unit per Liter (IU/L)

Question 33

Unit for amount of enzyme that will catalyze the reaction of 1 mole substrate per second under specified conditions

Answer 33

Katal Unit (mole/s)