PRELIM 03 - Enzyme Nomenclature, Kinetics, and Mechanism

Question 1

Are biological catalysts

Answer 1

Enzymes

Question 2

Are compounds whose reaction an enzyme catalyzes

Answer 2

Substrate

Question 3

Non-protein organic molecule (frequently a B vitamin) that acts as a cofactor

Answer 3

Coenzyme

Question 4

Non-protein portion of enzyme (an inorganic molecule) that is necessary for catalytic function

Answer 4

Cofactor

Question 5

A protein part of an enzyme

Answer 5

Apoenzyme

Question 6

The coenzyme or cofactor that is tightly bound to the apoenzyme

Answer 6

Prosthetic group

Question 7

An apoenzyme + prosthetic group

Answer 7

Holoenzyme

Question 8

Specific portion of the enzyme to which a substrate binds during reaction

Answer 8

Active site

Question 9

Any process that initiates or increases the activity of an enzyme

Answer 9

Activation

Question 10

Portion on the enzyme surface where inhibitors/activators bind to regulate catalytic reactions

Answer 10

Allosteric site

Question 11

Are compounds that slows down the rate of the reaction

Answer 11

Inhibitor

Question 12

Process that makes an active enzyme less active or inactive

Answer 12

Inhibition

Question 13

The enzyme is acting specifically to a bond or group attached to the substrate and acting specifically on it (Types of enzyme specificity)

Answer 13

Bond specificity

Question 14

The enzyme will act only on molecules that have specific functional groups (Types of enzyme specificity)

Answer 14

Group specificity

Question 15

Refers to the limited extent to which an enzyme can select and act on specific substrates (Types of enzyme specificity)

Answer 15

Substrate specificity

Question 16

The enzymes are specific to the substrates and their optical configuration (Types of enzyme specificity)

Answer 16

Optical specificity

Question 17

An enzyme can bind to different substrate that have similar molecular geometry (Types of enzyme specificity)

Answer 17

Geometrical specificity

Question 18

The enzyme reaction can be allowed if only the substrate and the co-factor are the same and match, which is highly specific (Types of enzyme specificity)

Answer 18

Co-factor specificity

Question 19

2 mechanisms of catalysis

Answer 19

Lock and Key, Induced fit

Question 20

In the same way only certain keys fit a lock, only certain substrates fit an enzyme’s active site (Mechanisms of catalysis)

Answer 20

Lock and key

Question 21

The shape of the active site within enzymes is malleable and can be induced to fit the substrate through a variety of mechanisms (Mechanisms of catalysis)

Answer 21

Induced fit

Question 22

Involves oxidation-reduction reactions (Classifications of enzymes)

Answer 22

Oxidoreductase

Question 23

Involves group transfer (Classification of enzymes)

Answer 23

Transferase

Question 24

Involves breaking of bonds in the presence of water (Classification of enzymes)

Answer 24

Hydrolase

Question 25

Involves the addition or removal of double/triple bonds (Classification of enzymes)

Answer 25

Lyase

Question 26

Involves isomerization reactions (Classification of enzymes)

Answer 26

Isomerase

Question 27

Involves formation of new bonds (Classification of enzymes)

Answer 27

Ligase

Question 28

Measure how fast the enzyme-catalyzed reaction happens

Answer 28

Enzyme activity

Question 29

Enzyme concentration and rate of reaction is directly proportional (Factors affecting enzyme activity)

Answer 29

Enzyme concentration

Question 30

At low substrate concentration, the relationship of it with reaction rate is directly proportional. At high substrate concentration, the reaction rate plateaus because of saturation (Factors affecting enzyme activity)

Answer 30

Substrate concentration

Question 31

__________ kinetics happen at low substrate concentrations

Answer 31

First order kinetics

Question 32

__________ kinetics happen at high substrate concentrations

Answer 32

Zero order kinetics

Question 33

Is the rate equation for a one-substrate enzyme-catalyzed reaction

Answer 33

Michaelis-Menten equation

Question 34

Is a graphical representation of enzyme kinetics

Answer 34

Lineweaver-Burke plot

Question 35

Is the number of moles of substrate converted to products per mole of enzyme per unit time

Answer 35

Turnover number (Kcat)

Question 36

Change in pH alters the charge of amino acid residues found in the active site (Factors affecting enzyme activity)

Answer 36

pH

Question 37

The pH at which an enzyme exhibits maximum activity

Answer 37

Optimal pH

Question 38

3 types of inhibitors

Answer 38

Competitive, Non-competitive, Uncompetitive

Question 39

Directly binds to the active site; competes against the substrate in binding to the active site (Types of inhibitors)

Answer 39

Competitive inhibitor

Question 40

Binds to allosteric sites; alters the enzyme conformation (Types of inhibitors)

Answer 40

Non-competitive inhibitors

Question 41

Do not compete with the substrate for binding to the active site, and they only bind to the enzyme-substrate complex (Types of inhibitors)

Answer 41

Uncompetitive inhibitors

Question 42

2 step processes in catalysis

Answer 42

Enzyme-substrate complex formation, Conversion of substrate to product