Enzymes

Question 1

protein that serves some
catalytic function in the body

Answer 1

enzyme

Question 2

Allow reactions to occur in the
body that would be impossible
otherwise

Answer 2

enzymes

Question 3

Has a specific substrate, and
this recognizes its substrate
with extremely high specificity

Answer 3

enzyme

Question 4

lowers the activation
energy of a reaction

Answer 4

catalyst

Question 5

area in the enzyme
where the substrate will bind to

Answer 5

active site

Question 6

will bind to the active site
because it has just the right shape
and composition

Answer 6

substrate

Question 7

enzyme
changes shape slightly once the
substrate inside the active site

what model

Answer 7

induced fit-binding

Question 8

complex where enzyme changes
shape as substrate binds

Answer 8

enzyme substrate complex

Question 9

complex where enzyme leaves the
substrate

Answer 9

enzyme products complex

Question 10

enzyme will end in this suffix

Answer 10

-ase

Question 11

breaks down lactose into
galactose and glucose

Answer 11

lactase

Question 13

Type of enzymes (6)

Answer 13

hydrolase
lyase
ligase
transferase
isomerase
oxidoreductase

Question 14

catalyzes
hydrolysis (separates a
molecule into two pieces)

what kind of enzyme

Answer 14

hydrolase

Question 15

cleaves covalent
bonds (other than hydrolysis)

what enyzme

Answer 15

lyase

Question 16

combines two
molecules

Answer 16

ligase

Question 17

transfers
functional group

Answer 17

transferase

Question 18

catalyzes
rearrangement

Answer 18

isomerase

Question 19

transfers
electrons from one molecule
to another

Answer 19

oxidoreductase

Question 20

an enzyme and
substrate can be this once the
enzyme operates on its substrate

what kind of bond

Answer 20

covalently linked

Question 21

needs to bind
to the enzyme before it can operate
on the substrate

Answer 21

cofactor/coenzyme

Question 22

are globular proteins that
serve as catalyst of biochemical
reactions

Answer 22

enzymes

Question 23

where the
reactant or substrate binds within
the enzyme called the active site

Answer 23

hydrophobic cleft

Question 24

also known as active
site

Answer 24

catalytic site

Question 25

eventually dissociates to form the
product and with subsequent
recovery of the enzyme

Answer 25

Enzyme-substrate complex

Question 27

This process results to a
lower energy of activation (Eα)
hence facilitating a faster
reaction

Answer 27

dissociation of ES complex

Question 28

this characteristic of
the reaction remains constant as
illustrated below

Answer 28

enthalpy

Question 29

study of the
velocity of enzymatic reaction

Answer 29

enzyme kinetics

Question 30

introduced by
Emil Fischer, wherein the enzyme
and its substrate have
complementary, which means the
substrate fit through the enzyme
active site like a key fits into a lock

Answer 30

lock and key model

Question 31

introduced by
Daniel Koshland, wherein the loose
binding of the substrate into the
active site of the enzymes induces a
conformational change in the active
site that results in a tighter fitting of
the substrate

Answer 31

induced fit model

Question 32

proposed a systematic
scheme of classifying and naming
enzymes

Answer 32

International Union of Biochemistry (IUB)

Question 33

Six general classes of enzymes

Answer 33

oxidoreductase
transferase
ligase
lyase
isomerase
hydrolase

Question 34

transfers
electron by two processes

Answer 34

oxido-reductases

Question 35

loss of
electron which usually
manifests as increase
in bonding with oxygen
and/or decrease of
bonding with hydrogen

Answer 35

oxidation

Question 36

gain of
electron which usually
manifests as increase
in bonding with
hydrogen and/or
decrease of bonding
with oxygen

Answer 36

reduction

Question 37

the
intermolecular transfer of a
chemical group or moiety

what enzyme

Answer 37

transferase

Question 38

the breakage of
a chemical bond by addition of
water

what enzmye

Answer 38

hydrolases

Question 39

the breakage of a
chemical bond by without the
addition of water or not
through oxidation-reduction

what enzmye

Answer 39

lyases

Question 40

the
intramolecular transfer of a
chemical group or bond
rearrangement within the
same molecule
(isomerization)

Answer 40

isomerase

Question 41

the formation of a
new chemical by joining two or
more molecules together

Answer 41

ligases

Question 42

identify the enzyme in pics

Answer 42

+1

Question 43

nonprotein part in
order to function properly

Answer 43

prosthetic group

Question 44

vitamins

co-enzmyes or co-factors

Answer 44

co-enzymes

Question 45

minerals or metals

co-enzymes/co-factors?

Answer 45

co-factors

Question 46

vitamins that serve as
this are the vitamin B complex and
vitamin C, which are all water soluble
vitamins

Answer 46

co-enzymes

Question 47

minimum amount of
nutrients that should be taken daily
from dietary source or
supplementation

Answer 47

recommended dietary allowance (RDA)

Question 48

disorder that is the loss of appetite, peripheral neuropathy, fatigue, loss of muscle coordination (ataxia)

Answer 48

beri-beri

Question 49

milder form of beri-beri

Answer 49

Wernicke-Korsakoff syndrome

Question 50

inflammation and scaly appearance of skin

Answer 50

scaly dermatitis

Question 51

inflammation of cracking of lips corner

Answer 51

angular cheilitis

Question 52

redness and swelling of the thongue

Answer 52

glossitis

Question 53

characterized by dermatitis, diarrhea, and memory loss (dementia)

Answer 53

pellagra

Question 54

convulsions, peripheral neuropathy, irritability, depression

Answer 54

neurologic disruptions

Question 55

numbness and tingling sensation of extremities

Answer 55

megaloblastic anemia paresthesia

Question 56

inflammation of gums, joint pains, impaired wound healing, weakness

Answer 56

scurvy

Question 57

scurvy is deficiency of

Answer 57

ascorbic acid

Question 58

beri beri and wermicle korsaloff syndrome is deficiency of

Answer 58

thiamine

Question 59

scaly dermatitis and angular cheilitis is a deficiency of

Answer 59

riboflavin

Question 60

pellagra is a deficiency of

Answer 60

niacin

Question 61

neurologic disruptions, anemia, glossitis is the deficiency of

Answer 61

pyridoxine

Question 62

dermatitis, hair loss, muscle pain is due to the deficiency of

Answer 62

biotin

Question 63

megaloblastic anemia and neurological defects is due to the deficiency of

Answer 63

folic acid

Question 64

megaloblastic anemia, paresthesia, neurological defects is due to the deficiency of

Answer 64

cobalamin

Question 65

metals are electrophilic
groups that aid in the functioning of
enzymes

Answer 65

cofactors

Question 66

Coordinated by certain amino
acid residues in the enzyme

Answer 66

cofactors

Question 67

Induce by coordination a
specific lock geometry for the
attachment of substrates and
maintenance of the native
conformation of the enzyme

Answer 67

cofactors

Question 68

Can also activate certain
bonds in the enzyme and/or
substrate to facilitate
catalysis

Answer 68

cofactors

Question 69

answer cofactor table

Answer 69

+1

Question 70

states
that every chemical reaction requires
collision between the reactant
particles and a successful reaction
occurs when the colliding particles
are in proper orientation and collides
with sufficient energy

Answer 70

collision theory of reaction

Question 71

When the substrate bind at the
enzyme’s active site, it
minimizes the energy of
activation and bring the
substrate particles at a proper
orientation during their
collision

Answer 71

collision theory of reaction

Question 72

wherein the transition state makes
better contacts with the active site of
an enzyme than the substrate, hence,
sufficient binding energy is not
reached until the substrate enters
the transition state

Answer 72

transition state stabilization

Question 73

classically theorized that
these occurs as the enzyme
somehow causes the substrate
particles to become distorted toward
the transition state

Answer 73

conformational distortion or stain effect

Question 74

the
enzyme’s active site is also known as
this, which means that it has much
fewer water molecules as compared
to the exterior of the enzyme

Answer 74

hydrophobic pocket or cleft

Question 75

effect involving
the lowering of local dielectric
constant surrounding the substrate
particles

Answer 75

desolvation effect

Question 76

Enhances the electrostatic
interactions of the substrate
particles and the enzyme’s
active site

Answer 76

desolvation effect

Question 77

Prevents the undue reaction of
water molecules to the
substrate to form unwanted
side products

Answer 77

desolvation effect

Question 78

Charged functional groups
also stabilizes the reaction
intermediates

Answer 78

desolvation effect

Question 79

the side chain
functional group of several amino
acids can donate or accept proton,
hence facilitating this

Answer 79

acid-base catalysis

Question 80

the protonation and
deprotonation results to more
reactive intermediates than the
original substrates, hence, the
reaction occurs at a faster rate

Answer 80

cascade

Question 81

serves as a base catalyst
for the enzyme acetylcholinesterase

Answer 81

histidine

Question 82

can form between the
substrate and electrophilic or
nucleophilic group amino acid
residue in the enzyme’s active site

Answer 82

transcient or intermediate covalent bond

Question 83

can also form this
intermediate covalent bond with the
substrate

Answer 83

prosthetic group

Question 84

in this, serine
residue forms a transient acyl-serine
covalent bond with the protein
substrate to facilitate the catalysis

Answer 84

chymotrypsin

Question 85

metal ion is tightly
bound (Fe3+, Cu2+, Zn2+)

Answer 85

metallozenymes

Question 86

metal ion
is loosely bound (Na+, K+, Mg2+, Ca2+)

Answer 86

metal-activated enzyme

Question 87

metal is
bound in an organic prosthetic group
(such as in Fe2+ in heme)

Answer 87

organometallic enzyme

Question 88

Metal can perform any of the
following functions (4)

Answer 88

➢ Bind the substrate in specific
orientation or lock geometry
➢ Mediate electron transfer
➢ Electrostatically stabilize or
shield negative charges
➢ Stabilize the transition state

Question 89

enzymes are
usually localized within a region or
organelle in the cells

Answer 89

compartmentation

Question 90

degrade worn
out organelles and
biomolecules, are confined
within the lysosomes

Answer 90

hydrolases

Question 91

pH of this
organelle optimizes the
activity of hydrolases

Answer 91

acidic pH

Question 92

the
reversible attachment of a chemical
group to specific amino acid residues
in the enzyme may result to its
activation or deactivation

Answer 92

covalent modification

Question 93

attachment
of phosphate group is
common way of regulating the
activity of an enzyme

Answer 93

phosphorylation

Question 94

Accomplished by either, cyclic
adenosine monophosphate
(cAMP), cyclic guanosine
monophosphate (cGMP), or
kinase

Answer 94

covalent modification

Question 95

is attached on
serine, threonine, or tyrosine
residues

Answer 95

phosphate

Question 96

adds a large
negative charge to the enzyme
that changes its conformation.
This leads to an increase or a
decrease in the activity of the
enzyme.

Answer 96

phosphate

Question 97

noncovalent
bonding of small molecules called
effectors to sites in the enzymes
other than the active site

Answer 97

allosteric regulation

Question 98

Interaction induces
conformational changes that
activate or deactivate the
enzyme

Answer 98

allosteric regulation

Question 99

enzymes
that are acted upon by such
effectors, made up of several
subunits that contain various
regulatory sites

Answer 99

allosteric enzymes

Question 100

deactivation of allosteric
enzyme by one of its products

Answer 100

feedback initiation

Question 101

removal of
some amino acid residues from an
inactive enzyme to convert it to its
active form

Answer 101

proteolytic modification

Question 102

inactive forms of
enzymes and proteins

Answer 102

zymogens

Question 103

inactive enzyme
to form trypsin

Answer 103

trypsinogen

Question 104

inactive
enzyme to form chymotrypsin

Answer 104

chmotrypsinogen

Question 105

in
proteolytic modification,
specific acid residues are
removed, and the fragments
are joined by this bridges to
make them functional

Answer 105

disulfide bridges

Question 106

regulation
of the genes that encode for a
particular enzyme

Answer 106

transcriptional control

Question 107

can directly or indirectly
affect the expression of these
genes

Answer 107

hormones and growth factor

Question 108

activates a
series of enzymes and
proteins that ultimately affect
gene expression (regulatory
substance is polar)

Answer 108

cascade pathway

Question 109

if a
regulatory substance is nonpolar,
it crosses the cell
membrane and binds to this
which passes through the
nucleoplasm and binds
directly to a specific segment
in the dna

Answer 109

cytoplasmic receptors

Question 110

the active site of
the enzyme is not exactly compatible
with its substrate. Upon entry in the
active site, the enzyme changes in
conformation to make a better fit
with the substrate

Answer 110

induced fit model

Question 111

Proximity effect in catalysis pertains
to what particular phenomenon?

a. The decrease in the energy of
activation as the substrate
molecules enter the active site of
the enzyme

b. Desolvation effect inside the
active site of the enzyme

c. The increase in local
concentration due to the
exclusion of interfering
substances from the active site

d. The transfer of specific chemical
moiety from the enzyme to the
substrate inside the active site

Answer 111

The increase in local
concentration due to the
exclusion of interfering
substances from the active site

Question 112

Metal ions are important in proper
functioning of many enzymes. How do
they mediate catalysis?
I. Bind to the substrate in a specific
lock geometry which is the proper
orientation for its reaction
II. Serve as mediator of electron
transfer
III. Stabilize nucleophilic substrate
and associated transition state
conformation

Answer 112

I, II, and III

Question 113

Enzyme facilitates catalysis by
formation of phosphoester bond with the phosphate group of the substrate.
Which amino acid residue can
facilitate such mechanism of
catalysis?

A. Aspartic acid
B. Serine
C. Glutamine
D. Lysine

Answer 113

Serine

Question 114

Between ES complex formation and
its dissociation to the enzyme and
products, which is the faster process
and why?

a. Formation of ES complex because
it requires more energy
b. Formation of ES complex is faster
because the substrate can readily
bind to the enzyme
c. Formation of ES complex to the
enzyme and products is faster
because the process requires
less energy
d. The dissociation of ES complex to
the enzyme and products is faster
because the products are less
stable than the substrate

Answer 114

c. Formation of ES complex to the
enzyme and products is faster
because the process requires
less energy

Question 115

Many nutritional deficiency in B
vitamins are associated with what
symptoms?
I. Neurologic
II. Hematologic
III. Cutaneous

Answer 115

I, II, and III

Question 116

In the formation of molecule A-B
from reactans A and B, the heat
evolved in the reaction is 175 kJ/mol while the energy of activation is 545
kJ.

Among the given substances,
which one was able to facilitate
catalysis for such reaction?

Answer 116

Addition of substance Z which
resulted to the heat evolved in the
reaction at -175 kJ/mol and
energy of activation at 286 kJ.

Question 117

Enzyme facilitates catalysis by
formation of ester bond with an
alcoholic substrate. Which amino
acid residues can facilitate such
mechanism of catalysis

a. Ser and Tyr
b. Lys and Arg
c. Cys and Met
d. Glu and Asp

Answer 117

Glutamic Acid and Aspartic Acid

Question 118

The active site of an enzyme has the
following amino acid residues as
critical mediators of catalysis: Ser-
134, His-347, Tyr-121, and Glu-406.
What are the most likely specific
mechanism of catalysis by these
amino acid residues?

a. Conformational distortion and
electrostatic effect
b. Acid-base catalysis and
electrostatic effect
c. Covalent catalysis and
conformational distortion
d. Covalent catalysis and acid-base
catalysis

Answer 118

d. Covalent catalysis and acid-base
catalysis

Question 119

According to the Collision Theory of
Reaction, what are the requirements
for the formation of the product from
colliding reactant molecules?

Answer 119

a. The reactants molecules should
collide with the reacting
functionalities facing each other

Question 120

Why are prosthetic groups essential
for many enzymes?

I. They have organic
components that can facilitate
catalysis by covalent bond
formation
II. They have metal ions that can
serve as electron pair
acceptor
III. They have certain amino acids
residues that can serve as
acid-base catalyst

Answer 120

I and II

Question 121

All of the following are
characteristics of all enzymes
EXCEPT?

a. Made up entirely of amino acid
residues
b. Water-soluble proteins with
spherical shape
c. Facilitate catalysis without being
consumed in the overall process
d. Amino acid side chains that are
critical for facilitating catalysis
e. Catalytic region that stabilizes the
substrate transition state

Answer 121

a. Made up entirely of amino acid
residues

Question 122

The classic concept of bond strain is
more correctly described in what
way?

a. Chemical bonds of the substrate
is distorted due to the presence of
metal ions in the vicinity of the
active site
b. Transition state makes better
contact with the enzyme than the
substrate due to stabilization
effect of various moieties in the
active site
c. The election cloud of the
substrate is polarized by more
electronegative moieties in the
active site
d. The transfer of electron from one
chemical moiety to another
results to decrease in steric
hindrance

Answer 122

b. Transition state makes better
contact with the enzyme than the
substrate due to stabilization
effect of various moieties in the
active site

Question 123

Which of the following is a
mechanism of catalysis by coenzymes?
I. They perform intermediate
covalent bond with the
substrate molecules
II. They polarize bonds because
of their electrophilic nature
III. They facilitate electron
transfer

Answer 123

I and II

Question 124

FoF1 ATPase is the enzyme that
catalyzes ATP synthesis. The enzyme
itself is deactivated by ATP. What
mode of enzyme regulation is being
exemplified?

a. Proteolytic modification
b. Covalent modification
c. Allosteric modification
d. Compartmentation

Answer 124

covalent modification

Question 125

Glycogen synthase enzyme is
regulated with the addition of
phosphate group on nine serine
residues. What mode of regulation is
being exemplified?

A. Covalent modification
B. Compartmentation
C. Proteolytic modification
D. Allosteric regulation
E. Transcriptional control

Answer 125

A. covalent modification

Question 126

Enzyme has an all important histidine
residue in its active site such that
substitution with any other amino
acid would result to the loss of
catalytic activity. What are the
possible mechanisms by which this
histidine residue may facilitate
catalysis?

I. Acting as proton acceptor
II. Forming of covalent bond with
the substrate via an ester
bond
III. Serve as stabilizer of
electrophilic substrate
because of its nucleophilic
character

Answer 126

I and II

Question 127

All of the following are
characteristics of an enzymes
EXCEPT?

a. Has a complementary shape to its
substrate
b. Found somewhere in the interior of
the enzyme
c. Binding site for many different kinds
of molecules
d. Less water content compared to the
cytoplasm

Answer 127

c. Binding site for many different kinds
of molecules

Question 128

what is the general equaiton for an enzyme-catalyzed reaction

Answer 128

+1 every turn

Question 129

formation of
the ES complex is slower and
reversible, hence is said to be this

Answer 129

rate determining step

Question 130

their
model states that the velocity of the
reaction is measured as a function of
substrate concentration until the
maximum velocity (Vmax) of the
reaction is reached as given in the
equation below:

Answer 130

michaelis menten equation

Question 131

michaelis menten equation

Answer 131

grade yourself accordingly

Question 132

reaction rate
constant is known as this, and is
actually a composite of the rate constants of ES complex form

Answer 132

michaelis constant

Question 133

yields a
hyperbolic curve where Vmax is the
horizontal asymptote of the curve
and KM is the substrate concentration
at one-half the Vmax

Answer 133

michaelis menten plot

Question 134

value of KM
represents this point of the enzyme
for its substrate which is inversely
proportional to the affinity of the
enzyme for the substrate

Answer 134

saturation point

Question 135

means a high saturation
point of the enzyme which results
from the low affinity of the enzyme
for the substrate

Answer 135

high KM

Question 136

means a low saturation
point of the enzyme which results
from the high affinity of the enzyme
for the substrate

Answer 136

low KM

Question 137

substance that slows
down the rate of reaction by binding to a specific region in the enzyme or
the ES complex

Answer 137

inhibitor

Question 138

three general types of inhibitors
based on their mode of binding

Answer 138

competitive inhibitor
noncompetitive inhibitor
uncompetitive inhibitor

Question 139

substrate analogue, which
means that its structure is
closely related to that of the
substrate

Answer 139

competitive inhibitor

Question 140

competes for the same
region in the active site
of the enzyme with the
substrate

Answer 140

competitive inhibitor

Question 141

Km value and Vmax value in competitive inhibitor

Answer 141

Vmax = same
Km = higher

Question 142

have an intersection at
the y-intercept

Answer 142

competitive inhibitor

Question 143

to counteract the effect
of this inhibitor, its
concentration should
be increased

Answer 143

competitive inhibitor

Question 144

binds to the site in enzyme
other than the active site

Answer 144

noncompetitive inhibitor

Question 145

vmax and Km in noncompetitive inhibitor

Answer 145

lower vmax
Km = unchanged

Question 146

have intersection at the
x-intercept

Answer 146

noncompetitive inhibitor

Question 147

binds to the enzymesubstrate
complex and
usually occurs for a reaction
with two or more substrate or
products

Answer 147

uncompetitive inhibitor

Question 148

vmax and Km in uncompetitive inhibitor

Answer 148

Vmax = lower
Km = lower

Question 149

parallel in the
superimposed
Lineweaver-Burk plots

Answer 149

uncompetitive inhibitor

Question 150

y = mx + b equivalent

Answer 150

check ppt slides

Question 151

read ppt slides for post lab

Answer 151

+1