Enzymology Flashcards
1
Q
injected enzymes
A
streptokinase, urokinase
2
Q
viral diseases (herpes, AIDS) treated by
A
azidothymidine
3
Q
treatment of acute lymphoblastic leukemia
A
glutaminase
4
Q
functional plasma enzymes
A
lipoprotein lipase, pseudocholinesterase
5
Q
sources of non-functional plasma enzymes
A
- cell damage (MI, viral hepatitis)
- Obstruction of normal pathways (obstruction of bile duct)
- increase of enzyme synthesis (bilirubin increases rate of ALP synthesis in obstructive liver disease)
- increased permeability of cell membrane as in hypoxia
6
Q
causes of increase serum level of enzymes
A
- increased cell turnover
- cellular proliferation (neoplasia)
- increased enzyme synthesis (enzyme induction )
- obstruction to secretion
- decreased clearance
7
Q
AST is also called
A
glutamate-oxaloacetate transaminase
8
Q
AST is significantly elevated in
A
MI
9
Q
AST is moderately elevated in
A
liver diseases
10
Q
ALT is also called
A
glutamate-pyruvate transaminase
11
Q
ALT normal serum level
A
5-30 U/L
12
Q
moderate increase of ALT
A
chronic liver disease (cirrhosis and malignancy)
13
Q
AST normal serum level
A
8-40 U/L
14
Q
very high values of ALT in
A
acute hepatitis
15
Q
AST is higher than ALT in
A
Acute Alcoholic hepatitis
16
Q
ALP present in
A
Liver, bone, intestines, kidneys and white blood cells
17
Q
ALP normal serum level
A
40-125 U/L
18
Q
ALP increases in
A
Cholestatic liver disease
19
Q
Placental ALP elevates in
A
Malignancies ( ovarian, lung, gastrointestinal cancers, hodgkin’s disease )
20
Q
Gamma-glutamyltransferase present in
A
Liver, also in intestines, kidneys, pancreas and prostate
21
Q
GGT normal serum level
A
6-45 U/L
22
Q
Nucleotide phosphatase also called
A
5’nucleotidase
23
Q
NTP is a marker enzyme for
A
Plasma membrane
24
Q
Normal NTP level
A
2-10U/L
25
NTP moderately increased in
Hepatitis
26
NTP is highly elevated in
Biliary obstruction
27
Silent MI occur in
Patients with DM
28
Biomarker released from damaged tissue within 1 hr
Myoglobin
29
Biomarker with high sensitivity but low specificity
Myoglobin
30
Time for myoglobin to rise is
1-4 hrs, peak time 6-12 hrs, return to normal in 24hrs
31
Why myoglobin has not been used by most hospitals
Due to its poor clinical specifity
32
Contractile protein not enzyme
Troponin
33
Found in cardiac and skeletal muscle, elevated during kidney and skeletal muscle damage
Troponin T
34
Troponin T early rise after
3-4hrs
| Peak is 24hrs
35
Found only in cardiac muscle
Troponin I
36
More specific
Troponin I
37
Troponin I rises
4-6hrs
Peak is at 18hrs
Returns to normal level in 14days
38
Can't be used to detect re-infarction
Troponin I
39
Can detect smaller infarction than other biomarkers can do (very sensitive)
Troponin
40
Enzyme catalyses the conversion of creatine to phosphocreatine
Creatine kinase
41
High specificity for cardiac tissue ( rise 4-6hrs)
CK
42
Peaks at about 12 hrs returns to baseline at 24-48 hrs
CK
43
Normal level of CK
15-100U/L for males
| 10-80 U/L for females
44
.......... catalyzes the conversion of pyruvate to lactate
Lactate dehydrogenase
45
normal level of LDH
55-140IU/L
46
if LDH1 is greater than LDH2, then the person is
positive for MI
47
LDH levels are high in
```
tissue breakdown
hemolysis
cancer
meningitis
encephalitis
HIV
```
48
An enzyme that has only limited diagnostic value because of its nonspecific nature
LDH
49
```
its elevation (8-12)hrs after infarction
peak levels (24-48)hrs after MI
```
AST
50
enzyme not indicative of MI, can cause a rise in the levels (as in trauma to the skeletal muscle, liver disease)
AST
51
catalyses the hydrolysis of starch into maltose
amylase
52
first enzyme to be discovered
amylase
53
normal level of amylase
140U/L
54
amylase is made in
pancreas and salivary gland
55
clinical significances of amylase
to diagnose pancreatitis
56
transient increase in activity of amylase with (2-12hrs)
acute pancreatitis
57
serum amylase may be raised in
bile duct obstruction & peptic ulcer
58
salivary gland diseases > raising the level of
amylase
59
hydrolytic enzyme, made by pancreatic acinar cells
lipase
60
digests fats into glycerol and fatty acids
lipase
61
lipase is made by
pancreatic acinar cells
62
normal lipase level
0-160U/L
63
amylase or lipase levels at least 3 times above the reference range are considered diagnostic of
acute pancreatitis
64
pancreatic lipase used to diagnose
Crohn's disease, Cystic fibrosis, celiac disease
65
aldolase A predominates in
muscle
66
aldolase B predominates in
liver
67
aldolase C predominates in
brain
68
Aldolase A expression is repressed in
Adult liver
| kidney and intestine
69
found in actin-containing filament of cytoskeleton, regulates cell contraction through its reversible binding to these filaments
Aldolase A enzyme
70
aldolase A (fructose-bisphosphate aldolase)
catalyzes the conversion of fructose-1,6-bisphosphate to glyceraldehyde 3-phosphate & dihydroxyacetone phosphate
71
aldolase A deficiency associated with
hemolytic anemia, myopathy
72
highest level of acid phosphatase found in
prostate cancer
73
moderate increase in PAP
diseases of bone ( Paget's disease, osteoporosis) hyperparathyroidism, diseases of blood cells "sickle-cell disease or multiple myeloma"
lysosomal storage diseases (Gaucher's disease)
74
more specific for screening or for detection early cancer
PSA
75
PSA is found in 2 forms in circulation
majority> complexed &some proteins
| minor > free
76
enzymes used in chemotherapy
methotrexate (blocks the action of dihydrofolate reductase)
77
enzymes used in antibiotics
penicillin & vancomycin
78
enzymes used in pesticides
ACH E inhibitors
79
ACH E inhibitor is used in agriculture in the form of
organophosphate pesticides
80
An example of a toxic peptide (natural poisons) is
alpha-amanitin (death cap mushroom)
81
a potent enzyme inhibitor, preventing RNA polymerase II enzyme from transcribing DNA
alpha-amanitin
82
abnormal metabolism of carbohydrates
diabetes mellitus
83
abnormal metabolism of fats
tay sachs, niemann-pick diseases
84
abnormal metabolism of amino acids
alkaptonuria or albinism
85
(autosomal recessive rare disorder) affect the body ability to breakdown galactose (in milk) to glucose
galactosemia
86
galactose can cause damage to the
brain, kidney , liver and eyes
87
enzymes of the galactose metabolism
galactokinase, galactose-1-phosphate uridyltransferase and UDP-galactose 4-epimerase
88
function of G6PD
regenerates NADPH allowing regeneration of glutathione
89
glutathione function
protects against oxidative stress
90
lack of G6PD leads to
hemolysis
91
X-linked recessive disorder results in
defective glucose 6-phosphate dehydrogenase enzyme > non-immune hemolytic anemia
92
G6PD complications include
anemia & newborn jaundice q3
