Ch. 13 Enzymes - Clinical Enzymology Lecture Flashcards
(77 cards)
1
Q
Specific biologic proteins that catalyze biochemical reactions w/o altering the equilibrium point of the rxn or being consumed or changed in composition
A
Enzymes
2
Q
Enzymes are frequently found in _____ following cellular injury
A
Serum
3
Q
A cavity of an enzyme where substrates bind and undergo a chemical reaction.
A
Active Site
4
Q
A water-free cavity, where the substance on which the enzymes acts interacts with particular charged amino acid residues.
A
Active Site
5
Q
The substance on which the enzyme acts.
A
Substrate
6
Q
A cavity other than the active site that binds regulatory (effector) molecules.
A
Allosteric Site
7
Q
Substances acted upon by enzymes
A
Substrate
8
Q
Enzymes that have similar enzymatic activity but differ in physical, biochemical and immunologic characteristics
A
Isoenzymes
9
Q
Enzymes with the same catalytic function throughout the body but exists in different forms within the same individual
A
Isoenzymes
10
Q
Results when an enzyme is subject to posttranslational modifications.
A
Isoform
11
Q
Non protein substances added in the enzyme substrate complex to manifest the enzyme activity
A
Cofactor
12
Q
Non protein molecule that may be necessary for enzyme activity
A
Cofactor
13
Q
Inorganic cofactors
A
Activators
14
Q
Organic cofactor
A
Coenzyme
15
Q
A coenzyme that is bound tightly to the enzyme
A
Prosthetic group
16
Q
Which is/are not an activator: Vitamins Chloride ion Nicotinamide adenine dinucleotide Magnesium ion Nicotinamide adenine dinucleotide phosphate Copper ion
A
NAD
Vitamins
Nicotinamide adenine dinucleotide phosphate
17
Q
Which is/are not a coenzyme: Vitamins Chloride ion Nicotinamide adenine dinucleotide Magnesium ion Nicotinamide adenine dinucleotide phosphate Copper ion
A
Chloride ion
Magnesium ion
Copper ion
18
Q
The protein portion of the enzyme that is also subject to denaturation, in enzyme losses activity
A
Apoenzyme
19
Q
An active substance formed by combination of a co-enzyme and an apoenzyme.
A
Holoenzyme
20
Q
Enzymes originally secreted from the organ of production in a structurally inactive form
A
Proenzyme or Zymogen
21
Q
Catalyze redox reaction between two substrates (A- + B → A + B-)
A
Oxidoreductases 1
22
Q
Catalyze the transfer of a group other than hydrogen (Phosphate, methyl, etc.) between two substrates (A-X + B → A + B-X)
A
Transferases 2
23
Q
Catalyze hydrolysis of various bonds
A–B + H2O → A–OH + B–H
A
Hydrolases 3
24
Q
Catalyze the removal of groups from substrates without hydrolysis; the product contains double bonds
ATP → cAMP + PPi
A
Lyases 4
25
Catalyze the interconversion of geometric, optical or positional isomers
A → B
Isomerases 5
26
Catalyze the joining of two substrate molecules, coupled with breaking of pyrophosphate bond in ATP or a similar compound
Ab + C → A–C + b
Ligases 6
27
```
Which among the given is/are Hydrolases:
Phosphatase (ALP, ACP)
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Lipase (LPS)
Fructose biphosphate aldolase (ALS)
Amylase (AMS)
Transferase (ALT, AST, GGT)
Dehydrogenase (Lactate Dehydrogenase)
Kinase (CK)
```
Amylase (AMS), Lipase (LPS), Phosphatase (ALP, ACP)
28
```
Which among the given is/are Oxidoreductases:
Phosphatase (ALP, ACP)
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Lipase (LPS)
Fructose biphosphate aldolase (ALS)
Amylase (AMS)
Transferase (ALT, AST, GGT)
Dehydrogenase (Lactate Dehydrogenase)
Kinase (CK)
```
Dehydrogenase (Lactate Dehydrogenase)
29
```
Which among the given is/are Transferases:
Phosphatase (ALP, ACP)
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Lipase (LPS)
Fructose biphosphate aldolase (ALS)
Amylase (AMS)
ALT
AST
GGT
Dehydrogenase (Lactate Dehydrogenase)
Kinase (CK)
```
ALT, AST, GGT, CK
30
```
Which among the given is/are Lyases:
Phosphatase (ALP, ACP)
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Lipase (LPS)
Fructose biphosphate aldolase (ALS)
Amylase (AMS)
ALT
AST
GGT
Dehydrogenase (Lactate Dehydrogenase)
Kinase (CK)
```
Fructose biphosphate aldolase (ALS)
31
```
Which among the given is/are Isomerases:
Phosphatase (ALP, ACP)
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Lipase (LPS)
Fructose biphosphate aldolase (ALS)
Amylase (AMS)
ALT
AST
GGT
Dehydrogenase (Lactate Dehydrogenase)
Kinase (CK)
```
Triphosphate isomerase (TPI)
32
```
Which among the given is/are Ligases:
Phosphatase (ALP, ACP)
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Lipase (LPS)
Fructose biphosphate aldolase (ALS)
Amylase (AMS)
ALT
AST
GGT
Dehydrogenase (Lactate Dehydrogenase)
Kinase (CK)
```
Glutathione Synthetase (GSH-S)
33
```
Which of the following is/are not Transferases:
Phosphatase (ALP, ACP)
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Lipase (LPS)
Fructose biphosphate aldolase (ALS)
Amylase (AMS)
```
All of the above
34
```
Which of the following is/are not Hydrolases:
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Fructose biphosphate aldolase (ALS)
ALT
GGT
Dehydrogenase (Lactate Dehydrogenase)
Kinase (CK)
```
All of the above
35
```
Which of the following is/are not Lyases:
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
Fructose biphosphate aldolase
ALS
```
```
Glutathione Synthetase (GSH-S)
Triphosphate isomerase (TPI)
```
36
The energy required to raise all molecules in 1 mol of a compound at a certain temperature to the transition state t the peak of the energy barrier.
Activation Energy
37
Catayze physiologic reactions by lowering the activation energy level that the reactants (substrates) must reach for the reaction to occur
Enzymes
38
The physical binding of a substrate to the active site of an enzyme
Enzyme-substrate complex
39
Refers to an enzyme combining with only one substrate and catalyzes only the one corresponding reaction.
E.g. CK, LD
Absolute Specificity
40
Refers to enzymes that combine with all substrates containing a particular chemical group, such as phosphate ester.
E.g. ACP, ALP
Group Specific
41
Refers to enzymes that are specific to chemical bonds
Bond Specificity
42
Refers to enzymes that predominantly combine with only one optical isomer of a certain compound.
E.g. LDH, G6PD
Sterioisometric specificity
43
```
The following are Group specific enzymes except:
CK
LDH
ALP
G6PD
```
CK
LDH
G6PD
44
```
Which of the following enzymes exhibit Absolute Specificity?
CK
LDH
ACP
LDH
```
CK
45
Enumerate the factors that influence enzymatic reactions
```
Substrate Concentration
Enzyme Concentration
pH
Temperature
Cofactors
Inhibitors
```
46
Hypothesized that the substrate readily binds to free enzyme at a low substrate concentration.
Michaelis and Menten
47
It follows that the reaction rate is directly proportional to the substrate concentration.
First-order kinetics
48
A reaction wherein only a fixed number of substrate (in excess) is converted to product per second; the reaction rate depends only on enzyme concentration
Zero-order kinetics
49
Changes in _____ may denature an enzyme or influence its ionic state, resulting in structural changes or a change in the charge of an amino acid residue in the active site.
pH
50
Used to carefully control and maintain the optimal pH in a reaction.
Buffer solutions
51
Common pH range; most physiologic reactions occur in this range.
7.0 - 8.0
52
Increasing _____ usually increases the rate of a chemical reaction by increasing the movement of molecules, the rate at which intermolecular collisions occur, and the energy available for the reaction
Temperture
53
Incubation of enzymes should be accurate within what temperature
(+/-) 0.1 C
54
Non protein entities that must bind to particular enzymes before a reaction occurs.
Cofactors
55
```
The following are some metallic activators except:
Ca2+
Fe2+
Zn2+
K+
Br-
Mg2+
Mn2+
Cl-
```
Br-
| Cl-
56
```
The following are some nonmetallic activators except:
Cl-
Ca2+
Fe2+
Br-
Mg2+
Mn2+
Zn2+
K+
```
```
Ca2+
Fe2+
Mg2+
Mn2+
Zn2+
K+
```
57
Serve as second substrates for enzymatic reactions
Coenzymes
58
Increasing _____ concentration will increase the velocity of an enzymatic reaction in a manner synonymous with increasing substrate concentration.
Coenzyme
59
A particular substance that interferes with enzymatic reactions
Inhibitor
60
A type of inhibitor that physically binds to the active site of an enzyme and compete with the substrate for the active site.
Competitive inhibitor
61
In competitive inhibition, the inhibition is reversible when the inhibitor is (greater/less than) the substrate. Explain.
Less than. The inhibition is reversible because the substrate is more likely than the inhibitor to bind to the active site.
62
Inhibition wherein the inhibitor binds to the ES complex
Uncompetitive inhibition
63
An inhibitor that binds an enzyme at a place other than the active site and may be reversible in that some naturally present metabolic substances combine reversibly with certain enzymes
Noncompetitive inhibitor
64
Explain why noncompetitive inhibtion may be irreversible and why increasing substrate concentration will not reverse the inhibition.
Noncompetitve inhibition may be irreversible when the inhibitor destroys part of the enzymes involved in catalytic activity. Increasing substrate concentration will not reverse the inhibition because the inhibitor binds directly to the enzyme.
65
Km stands for
Michaelis-Menten constant
66
It is an expression of the relationship between the velocity of an enzymatic reaction and substrate concentration
Km
67
Indicates the amount of substrate needed for a particular enzymatic reaction
Km
68
In Competitive inhibition, Km (increased/decreased/was unchanged)
Increased
69
In Noncompetitive inhibition, Km (increased/decreased/was unchanged)
Unchanged
70
In Uncompetitive inhibition, Km (increased/decreased/was unchanged)
Decreased
71
This type of inhibition can be counteracted by adding excess substrate to bind the enzyme.
Competitive inhibition. Reaction will proceed at a slower rate but to the same maximum velocity (Vmax) as an uninhibited reaction.
72
In this type of inhibition, maximum velocity cannot be achieved.
Noncompetitive inhibition
73
When substrate concentration is increased, inhibition is also increased in this type of inhibition. Also, maximum velocity equal to that of an uninhibited reaction cannot be achieved.
Uncompetitive inhibition.
74
A type of inhibition where:
Km increased
Vmax same with uninhibited reaction
Competitive inhibition
75
A type of inhibition where:
Km is unchanged
Vmax cannot be achieved
Noncompetitive inhibition
76
A type of inhibition where:
Km is decreased
Vmax equal to that of an uninhibited reaction cannot be achieved
Uncompetitive inhibition
77
What are the functions of Enzymes?
```
Hydration of Carbon Dioxide (respiration)
Nerve Induction
Muscle Contraction
Nutrient Degradation (Digestion)
Growth and Reproduction
Energy Storage and Use
```
