L4 - Enzymes

Question 1

From the Greek work “en” meaning “in” and
“zyme” meaning “yeast”

Answer 1

ENZYMES

Question 2

Study of enzymes

Answer 2

Enzymology

Question 3

composed only of protein (amino acid
chains)

Answer 3

Simple enzymes

Question 4

has a nonprotein part in addition to a
protein part

Answer 4

Conjugated enzymes

Question 5

the extent to which an enzyme’s activity is
restricted to a specific substrate, a specific group of
substrates, a specific type of chemical bond, or a specific
type of chemical reaction

Answer 5

ENZYME SPECIFICITY

Question 6

the enzyme will catalyze only one
reaction

Answer 6

Absolute Specificity

Question 7

the enzyme will act only on molecules
that have a specific functional group

Answer 7

Group Specificity

Question 8

the enzyme will act on a particular
type of chemical bond

Answer 8

Linkage Specificity

Question 9

the enzyme will act on a particular
stereoisomer

Answer 9

Stereochemical Specificity

Question 10

Acted upon by the enzyme and specific

Answer 10

Substrate

Question 11

“crevicelike” location in the enzyme

Answer 11

Active Site

Question 12

small part of an enzyme’s structure that is
actually involved in catalysis

Answer 12

Active Site

Question 13

binding site on the surface of an enzyme other
than the active site

Answer 13

Allosteric Site

Question 14

different forms of an enzyme that catalyze the
same reaction in different cells or tissues of the body

Answer 14

Isoenzyme

Question 15

the non protein part of a conjugated enzyme

Answer 15

Cofactor

Question 16

the protein part of a conjugated enzyme

Answer 16

Apoenzyme

Question 17

biochemically active conjugated enzyme
produced from an apoenzyme and a cofactor

Answer 17

Holoenzyme

Question 18

Apoenzyme + Cofactor =

Answer 18

Holoenzyme

Question 19

also called zymogen, the inactive form of a
proteolytic enzyme

Answer 19

Proenzyme

Question 20

The suffix -ase identifies a substance as
an enzyme

Answer 20

Substrate + ase

Question 21

is often noted in
addition to the type of reaction

Answer 21

Identity of the substrate

Question 22

catalyzes an oxidation–reduction
reaction

Answer 22

Oxidoreductase

Question 23

catalyzes the transfer of a functional
group from one molecule to another

Answer 23

Transferase

Question 23

catalyzes the transfer of
an amino group from one molecule to
another

Answer 23

Transaminase

Question 24

transfer of phosphate group from ATP to ADP + phosphorylated product

Answer 24

Kinases

Question 25

catalyzes a hydrolysis reaction in which the addition of a water molecule to a bond causes the bond to break

Answer 25

Hydrolase

Question 26

breaking of glycosidic bonds in oligosaccharides and polysaccharides

Answer 26

Carbohydrases

Question 27

breaking of peptide linkages in proteins

Answer 27

Proteases

Question 28

breaking of ester linkages in triglycerides

Answer 28

Lipases

Question 29

catalyzes the addition of a group to a double bond or the removal of a group to form a double bond in a manner that does not involve hydrolysis or oxidation.

Answer 29

Lyase

Question 30

removal of the components of water from a double bond

Answer 30

Dehydratase

Question 31

addition of water to a double bond

Answer 31

Hydratase

Question 32

catalyzes the isomerization (rearrangement of atoms) of a substrate in a reaction, converting it into a molecule isomeric with itself

Answer 32

Isomerase

Question 33

catalyzes the bonding together of two molecules into one with the participation of ATP

Answer 33

Ligase

Question 34

a general explanation of the velocity and gross mechanism of enzyme-catalyzed reactions

Answer 34

Michaelis-Menten Theory

Question 35

highly specific way an enzyme recognizes a substrate and binds it to the active site

Answer 35

Lock and Key Theory

Question 36

the flexibility of the active site allows it to adapt to the shape of the substrate

Answer 36

Induced-fit Model

Question 37

a measure of the rate at which an enzyme converts substrate to products in a biochemical reaction.

Answer 37

Enzyme Activity

Question 37

As the ___ of an enzymatically catalyzed reaction increases, so does the rate (velocity) of the reaction.

Answer 37

Temperature

Question 38

Small changes in ___ (less than one unit) can result in enzyme denaturation and subsequent loss of catalytic activity

Answer 38

pH

Question 38

Enzyme activity increases up to a certain substrate concentration and thereafter remains constant

Answer 38

Substrate concentration

Question 39

Are those which proceed at a rate exactly proportional to the concentration of one reactant

Answer 39

First-order reaction

Question 39

Are those in which the rate is proportional to the product of the concentration of two reactants

Answer 39

Second-order reaction

Question 40

The reactions are zero-order with respect to the reactants

Answer 40

Zero-order reaction

Question 41

If the amount of substrate present is kept constant and the enzyme concentration is increased, the reaction rate increases because more substrate molecules can be accommodated in a given amount of time.

Answer 41

Enzyme concentration

Question 42

Nonprotein entities that must bind to particular enzymes before a reaction occurs

Answer 42

Cofactor

Question 43

Proper substrate binding

Answer 43

Activator

Question 44

Interfere with enzyme reactions

Answer 44

Inhibitor

Question 45

a substance that slows or stops the normal catalytic function of an enzyme by binding to it

Answer 45

Enzyme Inhibitor

Question 46

A molecule closely resembling the substrate.

Answer 46

Competitive inhibitor

Question 47

A molecule that binds to a site on an enzyme that is not the active site.

Answer 47

Noncompetitive inhibitor

Question 48

A molecule that forms a covalent bond to a part of the active site, permanently preventing substrates from occupying it

Answer 48

Irreversible inhibition

Question 49

Substances other than substrate or coenzyme are necessary and must be present in excess

Answer 49

Coupled-Enzymatic Assays

Question 50

Reactants are combined

Answer 50

Fixed-Time (Endpoint) Assays

Question 51

Multiple measurements

Answer 51

Continuous-monitoring (Kinetic) Assays

Question 52

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

Answer 52

International Unit (IU)

Question 53

Enzyme concentration

Answer 53

International Unit per Liter (IU/L)

Question 54

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

Answer 54

Katal Unit (mole/s)