INTRODUCTION TO ENZYMOLOGY

Question 1

Study of enzymes
1. Activity of enzymes
2. Chemical reactions it catalyzes
3. Clinical use

Answer 1

enzymology

Question 2

Increases the speed of reaction

Answer 2

Protein catalysts

Question 2

AKA excess energy

Answer 2

Activation Energy

Question 3

The molecule upon which an
enzyme acts

Answer 3

substrate

Question 3

Specific biologic proteins that
catalyze biochemical reactions

Answer 3

enzymes

Question 4

Often water-free cavity. Region of an enzyme where substrate molecules bind and undergo chemical reaction

Answer 4

active site

Question 5

changing the shape of the
enzyme or confirmation

Answer 5

Allosteric Site

Question 6

impairs activity of the enzyme

Answer 6

Allosteric inhibitor

Question 7

enhances activity of the enzyme

Answer 7

Allosteric activator

Question 8

Results when an enzyme is
subject to posttranslational
modification

Answer 8

Isoform

Question 9

Isoform of enzymes. Enzyme existing in different forms within the same individual but the same action

Answer 9

Isoenzyme

Question 10

Organic cofactor such as nicotinamide adenine dinucleotide

Answer 10

Coenzyme

Question 10

Inorganic cofactor like chloride
ion, magnesium ion

Answer 10

Activator

Question 11

Nonprotein molecule that may
be necessary for enzyme activity

Answer 11

Cofactor

Question 12

coenzyme that is bound tightly to the enzyme

Answer 12

Prosthetic group

Question 13

Ability of an enzyme to choose
exact substrate from a group of
similar chemical molecules

Answer 13

Enzyme Specificity

Question 13

• Enzymes may recognize and catalyze
• A single substrate
• A group of similar substrates
• A particular type of blood

Answer 13

Enzyme Specificity

Question 13

AKA Zymogen
Inactive form or precursor of
enzyme

Answer 13

proenzyme

Question 14

Oxidation and reduction

Answer 14

Oxidoreductase

Question 14

– removal of H ion

Answer 14

Oxidation

Question 15

– accept H ion

Answer 15

Reduction

Question 16

Addition of water to a bond resulting in bond breakage

Answer 16

Hydrolases

Question 17

Transfer of functional groups other than hydrogen from one
substrate to another

Answer 17

Transferases

Question 18

Catalyze the joining of two large molecules by forming a new chemical bond

Answer 18

Ligases

Question 18

Proposal that enzyme catalysis is a two-step process that consists of an initial adsorption whereby the substrate combines with the enzyme to form a noncovalent enzymesubstrate (ES) complex, followed by a second step in which the ES complex decomposes into product (P) and free enzyme (E).

Answer 18

Michaelis-Menten Theory

Question 19

Catalyze removal of groups from substrates without hydrolysis; the product contains double bonds

Answer 19

Lyases

Question 20

Specific action of an enzyme with a single substrate postulated first by Emil Fischer in 1894

Answer 20

Lock and Key Theory

Question 20

Rearrange the functional groups within a molecule and catalyze the conversion of one isomer into another

Answer 20

Isomerase

Question 21

Concentration of substrates when the reaction reaches half of Vmax

Answer 21

Km

Question 21

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

Answer 21

Induced Fit Theory

Question 22

Maximum velocity or rate at which the enzyme catalyzed a reaction

Answer 22

Vmax

Question 23

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

Answer 23

Lineweaver-Burk Plot

Question 24

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

Answer 24

First-order reaction

Question 24

temp for denaturation

Answer 24

40-50

Question 25

Reaction rate is independent of concentration of the reactants; increasing the concentrations of reactants does not speed up the rate of reaction

Answer 25

Zero-order reaction

Question 25

Reaction rate is directly proportional to the concentration of two reactants

Answer 25

Second-order reaction

Question 26

The higher the enzyme level, the faster the reaction will proceed

Answer 26

Enzyme Concentration

Question 26

pH level of enzymatic reactions

Answer 26

7.0-8.0

Question 26

amylase denatures at what temp

Answer 26

45

Question 27

normal temp for er

Answer 27

37

Question 27

assay temp

Answer 27

25,30, or 37

Question 27

ck denatures at what temp

Answer 27

37

Question 28

it is able to fit at the active site. when it is there, the substrate is unable to bind to the enzyme and the desired reaction does not occur.

Answer 28

competitive inhibition

Question 29

bound to the regulatory site. the active site is thus changed, and the substrate can't bind to the enzyme

Answer 29

noncompetitive inhibition

Question 30

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

Answer 30

Coupled-Enzyme Assay

Question 31

Reaction is stopped by denaturation using strong acid, strong base, detergent, heat, cold application, irreversible inhibitors, EDTA

Answer 31

Fixed-Time Method

Question 32

often convenient as a reagent for coupled-enzyme assay when neither NAD nor NADH is a coenzyme for the reaction

Answer 32

NAD or NADH

Question 33

Multiple measurements, usually of absorbance change, are made during the reaction at specific time intervals usually every 30 secs of 60 secs, or continuously by continuous-recording spectrophotometer

Answer 33

Continuous-Monitoring Method

Question 33

Amount of enzyme that will catalyze the reaction of 1 micromole of substrate per minute under specified conditions

Answer 33

International Unit

Question 34

Enzyme concentration

Answer 34

International Unit per Liter (IU/L)

Question 35

Amount of enzyme that will catalyze the reaction of 1 mole of substrate per second under specified conditions

Answer 35

Katal Unit (mole/s)