ENZYMOLOGY Flashcards
1
Q
These are the several distinct forms of enzymes. Important in the diagnosis of specificity
A
ENZYME VARIANT
2
Q
The multichained enzymes. Enzymes of similar activity typically appearing in specific tissue, organs and cell
organelles of organisms and the same species
A
ISOENZYMES
3
Q
Specifically located in tissues. The site of a specific isoenzyme is found and restricted to only one tissue
A
ISOENZYMES
4
Q
Lactate dehydrogenase subunits and bond
A
H and M subunits (polypeptide chains)
4
Q
H4 – LD1
A
heart, RBC, and renal tissues
4
Q
LD1
A
H4
5
Q
H3M – LD2
A
heart, RBC and renal tissues
6
Q
LD2
A
H3M
7
Q
H2M2 – LD3
A
– lungs, lymphocytes, spleen, pancreas
8
Q
LD3
A
H2M2
9
Q
HM3 – LD4
A
liver, skeletal muscle
10
Q
LD4
A
HM3
11
Q
M4 – LD5
A
liver, skeletal muscle
12
Q
LD5
A
M4
13
Q
Response to activation and inactivation process : ACP (RBC)
A
not inhibited by 2% formaldehyde
14
Q
Response to activation and inactivation process : ACP (prostate)
A
inhibited by 2% formaldehyde
15
Q
Relative substrate specificity : ACP (RBC) is less sensitive to
A
α-naphthyl PO4 substrate
16
Q
Same enzymatic activity, which are specie specific for different biological species
A
HETEROENZYMES
17
Q
- Genetically transmitted enzymes
- Important in defining the biochemical characteristics of individuals
A
ALLOENZYMES
18
Q
- Present only in some selected individuals of the same species
- Practical value in forensic medicine and genetics
A
ALLOENZYMES
19
Q
Generally secreted by liver into the plasma. Enzymes exert function in plasma
A
Plasma Specific Enzymes
20
Q
Enzymes that do not have specific function in plasma. The plasma lacks activators or coenzymes which are necessary for enzyme activity
A
Non-plasma specific enzymes
21
Q
2 classes of Non-plasma specific enzymes
A
- Enzyme of secretion
- Enzymes associated with cellular metabolism
22
Q
These are normally secreted enzymes like AMS
A
Enzyme of secretion
23
Enzymes secreted in plasma at a very high rate but are rapidly disposed off to normal excretory channels thus concentration in plasma is maintained at low and constant level
Enzyme of secretion
24
Enzymes that carry out their functions within the cells in which they are
formed. state examples
CK in heart and ACP in prostate gland
25
Enzymes based on distribution
A. Unilocular Enzymes
B. Bilocular enzyme
26
These are enzymes found only in the cell sap. Found only in one location
Unilocular Enzymes
27
These are enzymes that are found in the mitochondria and cell sap
Bilocular enzyme
28
formula of Enzyme Kinetics
E+S -------> ES --------> P+E
29
Enzyme Kinetics : E
= enzyme that represents a true catalyst
= not changed in the reaction
30
Enzyme Kinetics : S
substrate upon which the enzyme acts
31
Enzyme Kinetics : ES
the postulated enzyme – substrate complex
32
Enzyme Kinetics : P
= the reacted substrate
= product that represents a changed molecular species of substrate
33
this refers to the activation energy
Energy
34
E + S = commonness and sameness between
enzyme and substrate
Molecular compatibility
35
refers to the number of enzymes or substrates that can be reacted
Space availability
36
refers to the particular enzyme catalyzing a specific substrate
Specificity
37
Factors Affecting E and S Combination
A. Lock and Key
B. Induced Fit model
38
refers to the active site being complementary in shape and size of the substrate
Lock and Key
39
refers to the enzyme changing in shape during binding with
substrate. After binding, the shape of the enzyme complements with the binding
site
Induced Fit model
40
a. direct relationship
b. An increase in the concentration of substrate results to an increase in the
rate of enzyme activity
c. No free binding site
Substrate concentration
41
a. This refers to the condition when the enzymatic reaction is allowed to take
place
b. If the catalytic activity of an enzyme on the substrate is fast, it results to a
shorter enzymatic reaction time thereby the enzyme is freed and can act
again on the remaining substrate
Time
42
2 Phases of Enzyme Reaction
A. First Order Kinetics
B. Zero Order Kinetics
43
Enzyme concentration is fixed and the substrate concentration is
varied
First Order Kinetics
44
The rate of reaction is almost directly proportional to substrate
concentration at low values (lower substrate concentration than enzyme)
First Order Kinetics
45
The rate of reaction dependent on substrate concentration and on enzyme concentration
First Order Kinetics
46
The rate depends on the enzyme concentration and independent of substrate concentration
Zero Order Kinetics
47
An increase in the enzyme concentration results to an increase in the catalytic activity of the enzyme
Zero Order Kinetics
48
a. Direct relationship
b. An increase in the enzyme concentration result to an increase in the
catalytic activity of the enzyme
Enzyme Concentration
49
the point at which the enzyme molecule is capable of catalyzing the substrate with regards to temperature
requirement
Optimum temperature
50
optimum temperature
30-37C or 37-40C
51
what temperature does enzyme undergoes inactivation and denaturation (range)
60-70C
52
refers to the increased reaxtion rate for every 10C increase
(rate of reaction is doubled)
Q10 value
53
the point at which the reaction rate is greatest
optimum pH
54
at pH __ many enzymes show maximum activity
7-8
55
a. Required for full enzyme activity
b. These metal activators or inorganic entities help bind the substrate to the
active site by forming ionic bridges
c. These help substrate in orientation so it is attached to the protein at theproper point nd in the correct configuration
Activators
56
Divalent Cations
- Fe++
- Ca++
- Zn ++
57
Monovalent anions
Cl-
Br-
NO3-
58
Monovalent cations
K+
Na+
59
Substances that decrease the rate of enzyme reaction if these are
present in the reaction system
Inhibitors
60
Binds to the active site, blocking the access of the substrate to the enzyme
competitive inhibition
61
Inhibitor that
Binds elsewhere on the enzyme causing change in shape that interferes with substrate binding
non-competitive
62
inhibitors bind with the ES completely; no
product formed
Uncompetitive
63
When inhibitors are possibly removed from the system and enzyme is fully restored
Reversible inhibition
64
Physical separation processes that remove inhibitors
a. Dialysis
b. Gel filtration
65
1. When inhibitors combine covalently with the enzyme
2. Physical methods are ineffective in separating inhibitors
from enzymes
Irreversible inhibition
66
These must be present at the proper concentration for many enzyme reactions to take place
Coenzyme concentration
67
These are essentially coenzymes that firmly bind with enzymes
Prosthetic Group
68
It refers to the disruption of the structure of enzyme molecule (3-dimensional structure)
that leads to the loss of enzyme activity
Enzyme Denaturation
69
- Defined as the amount of enzyme which catalyzes the conversion of 1umol of substrate
in 1 minute
- Reported in IU/liter of sample
International Unit (IU)
69
- A unit of enzyme activity which converts 1 mol of substrate per second
- Has not yet received universal acceptance
Katal
69
the concentration of the product influences the rate of reaction
Feedback control
70
an interaction takes place at a position other than the active site but affects the active site, either positively or negatively
Allosterism
71
must be activated by removing a small
portion of the polypeptide chains.
proenzymes or zymogens
