Introduction to Enzymes Flashcards
1
Q
Biologic protein that catalyze biochemical reaction
A
Enzyme
2
Q
Enzyme decreases or increases velocity in the reaction?
A
Increases
3
Q
Enzyme only acts as ______; since it ______
A
participant; not consumed, nor change reaction
4
Q
Majority of the enzymes are located ____
A
Intracellularly
5
Q
Functions of Enzyme
A
- Hydration of Carbon Dioxide (respiration)
- Nerve Induction
- Muscle contraction (locomotion)
- Growth and Reproduction
- Energy storage and use
6
Q
it is readily available in the presence of enzyme
A
Heat
7
Q
Components of Enzyme
A
Active Site
Allosteric Site
8
Q
binding site of substrate
A
Active site
9
Q
binds regulatory/effector molecules
A
Allosteric Site
10
Q
binding of active and substrate is
A
HIGHLY SPECIFIC
11
Q
Substance that ACTED UPON enzymes
A
Substrate
12
Q
Lactose metabolism is accelerated due to
A
Lactase
13
Q
Nonprotein portion of enzyme
A
Cofactor
14
Q
3 types of Cofactor
A
- Coenzyme
- Activator
- Isoenzyme
15
Q
Acts as second substrate
A
Coenzyme
16
Q
Coenzyme is ORGANIC OR INORGANIC cofactor?
A
Organic
17
Q
Example of Coenzymes
A
NAD
18
Q
Nonmetallic or Metallic cofactor
A
Activator
19
Q
Non metallic Activator are
A
Bromide
Chloride
20
Q
Metallic Activator are
A
MICZ
Magnesium
Iron
Calcium
Zinc
21
Q
Cofactor that has same enzymatic activity but differs in PHYSICAL, BIOCHEMICAL, IMMUNOLOGIC characteristics
A
Isoenzyme
22
Q
Example of Isoenzyme
A
CK Isoenzyme
CK-MM
CK-MB
CK-BB
23
Q
Protein portion of enzyme
A
Apoenzyme
24
Q
Susceptible for protein denaturation
A
Apoenzyme
25
Protein denaturation happens under what temp
56 deg cel.
26
Coenzyme + apoenzyme
Holoenzyme
27
coenzyme is tightly bound to the apoenzyme; coenzyme belongs to
Prosthetic group
28
Enzyme classification and name is based on
Enzyme Commission of IUB (International Union of Biochemistry)
29
Long name; Involves the:
Substrate
catalyzed reaction
Coenzyme
Systemic name
30
Usable name; commonly used
Recommended name/Trivial name
31
consist of four digits
Enzyme Commission Numerical Code
32
Enzyme Commission: First Digit
Enzyme Class
33
Enzyme Commission: Second Digit
Subclass
34
Enzyme Commission: Third Digit
Enzyme Sub Subclass
35
Enzyme Commission: Fourth Digit
Specific serial number of Enzyme
36
Enzyme Classes are the ff:
Oxidoreductase
Transferase
Hydrolase
Lyases
Isomerase
Ligases
37
Enzyme class that catalyzes the transfer of charged ions
Oxidoreductase
38
Redox reaction between 2 substrate
Oxidoreductase
39
Examples of Oxidoreductase enzyme:
Lactate Dehydrogenase (LDH)
Glucose Phosphate Dehydrogenase (G-6-PD)
40
Transfer of specific particular group other than hydrogen ion
Transferase
41
A- + B = A + B-
Oxidoreductase
42
A-X + B = A + B-X
Transferase
43
Transferase Enzymes are
Alanine Amino Transferase
Aspartate Amino Transferase
Gamma Glutamyl Transferase
Kinase (Creatine Kinase, Phosphokinase)
44
catalyze hydrolysis of various chemical bonds
Hydrolase
45
Hydrolase enzymes are
Amylase (glycosidic)
Lipase (Ester bond)
Phosphatase (monophosphoester bond)
- Acid Phosphatase
- Alkaline Phosphatase
46
catalyzes the removal of a particular chemical group from substrate w/o hydrolysis/water
Lyases
47
does lyases retain the double bond of an enzyme
Yes
48
A-B + H2O = A-OH + B-H
Hydrolysis
49
ATP --> cAMP + PPi
Lyases
50
Lyases enzymes are
Fructose biphosphate aldolase
51
catalyze interconversion of geometric, optical, and positional enzyme
Isomerase
52
A --> B
Isomerase
53
Isomerase enzymes are
Triphosphate isomerase
54
catalyze the joining of 2 substrate
Ligases
55
Example of Ligase enzyme
Glutathione synthetase
56
Ab + C = AC + b
Ligase
57
2 substrates joined together with
breaking of pyrophosphate bond in ATP
58
lower the activation energy needed by enzymes results to
fast chemical reaction
59
catalytic mechanism of enzyme
E + S = ES >>> E + P
60
Enzyme combined with only one substrate
Absolute specificity
61
Enzymes combined with all substrate of a particular chemical group
Group Specificity
62
Group Specificity example
Kinases (binds with phosphate group)
63
enzymes bind with the chemical bond
Bond specificity
64
Example of Bond specificity
Amylase (glycosidic)
Lipase (Ester)
Phosphatase (monophosphoester)
65
Enzymes bind with one specific optical isomer
Stereoisometric specificity
66
Factors that Influence Enzymatic Reactions
Substrate Concentration
Enzyme Concentration
Cofactor
Inhibitor
Storage
Hemolysis
Lactesence/Lipemic
67
Increase substrate concentration results to
Increase enzymatic reaction
68
Condition by which excessive increase of substrate no longer affects the enzymatic reaction
Saturation Kinetics
69
Measurement of Enzyme activity that uses an increasing amount of substrate concentration
First-Order Kinetics
70
Rate of Reaction is DIRECTLY PROPORTIONAL substrate concentration
First-Order Kinetics
71
Increasing substrate concentration is used in
First-Order Kinetics
72
FIXED number of substrates is converted to product
Zero Order Kinetics
73
Increased enzyme concentration
Faster chemical Reaction
74
TRUE / FALSE
All increased enzymes are clinically significant
false
75
Example of an enzyme that is normally increased
G-6-PD
76
Most physiologic reaction occurs @ what pH
7.0-8.0
76
Most physiologic reaction occurs @ what pH
7.0-8.0
77
Enzymes that can react with extremely low and high pH
Phosphatases
78
Acid Phosphatase pH
3-5
79
Alkaline Phosphatase pH
10
80
Plays a vital role in reaction
Temperature
81
enzyme is active at what temp
25, 30, 37 deg cel
82
room temperature
25 deg cel
83
optimum temperature for enzymatic activity
Body temperature (37 deg cel)
84
Denaturation starts at what temperature
40-50
85
Protein is denatured at what temp
56
86
Temperature by which enzyme is inactivated
60-65
87
Temperature coefficient/ Q10
for every 10 deg cel increase temperature = 2 fold increase in enzymatic activity
88
Enhances spacial configuration of the enzyme
Activator
89
3 kinds of Inhibitor
Competitive Inhibitor
Uncompetitive Inhibitor
Noncompetitive inhibitor
90
prevents substrate conversion to a product
Inhibitor
91
competes with substrate to the active site
Competitive inhibitor
92
Kind of inhibitor that binds with the allosteric site
Noncompetitive inhibitor
93
slow down or affect velocity of enzyme reaction; decreases substrate reaction
Competetive inhibitor
94
slow down or affect velocity of enzyme reaction; decreases substrate reaction
Competitive inhibitor
95
inhibitor that binds with Enzyme-Substrate Complex
Uncompetitive Inhibitor
96
Preferred temperature for storage that maintains the enzymatic activity for long period of time
-20 deg cel.
97
Substrate and Coenzyme temperature storage
2 - 8 deg. cel.
98
Temperature storage for LDH
Room temperature (25 deg cel)
99
Thawing of serum sample can be done ___
Once
100
Hemolysis can cause false INCREASED / DECREASED enzyme activity
INCREASED
RBC contains enzymes; hemolysis causes to release these enzymes causing false elevation of enzyme concentration
101
Lipemic, Lactescence, Milky specimen causes false INCREASED / DECREASE enzyme activity
Decrease
102
Increase product concentration
Decrease substrate concentration (substrate --> product)
103
Decrease in Coenzyme concentration (NADH)
- Coenzyme (second substrate, indicator)
- Commonly used in Oxidoreductase reaction
104
Redox Reaction happens in the presence of
Coenzyme
105
There is an INCREASED/DECREASED on altered coenzyme concentration during enzyme activity
Increased
106
Enzyme catalytic activity uses what substrate kinetics
Zero-order kinetics
107
Measurement of catalytic activity is done at what phase of reaction
LINEAR
108
General Method for Measuring Enzymatic activity
Fixed Time (2-point) Assay
Continuous Monitoring Assay / Kinetic Assay
109
mix reagents (substrate/coenzyme) and sample (enzymes)
incubate
measure
Fixed Time Assay
110
multiple measurement at specific time interval
Continuous Monitoring Assay
111
Commonly used interval
60 secs
112
Kinetic Assay uses what type of substrate kinetics
Zero-order kinetics
113
expression of the relationship between the velocity of the enzyme reaction and substrate concentration
Michaelis-Menten Equation
114
IU (EC) unit
1 substrate umol/min (umol/min)
115
SI unit
Katal (mol/sec)
116
measurement of enzymatic mass is used for
isoenzymes
117
Isoenzymes are measured through their
Electrophoretic migration
118
Theory that is based on binding of substrate (key) to the active site (lock)
Emil Fishers (Lock and Key theory)
119
Theory by which the configuration of the substrate would be manipulated so that it will fit to active site
Kochland's Induced fit Theory
