Test 4 Flashcards
(100 cards)
1
Q
What is the substrate for the enzyme aspartate amino transferase (AST)?
A
Aspartate and alpha ketoglutamic acid
2
Q
Creatinine is formed from the breakdown of what?
A
creatine
3
Q
PSP is removed from the body by what organ?
A
kidney
4
Q
What is the principle of the Berthelot reaction and what substances can falsely elevate values in the reaction?
A
hydrolysis of urea to ammonium carbonate by enzyme urease ammonia, lipemia, and icteric specimens
Color of the compound form is Blue indophenol
5
Q
Increased ALT values are associated with diseases of what organ?
A
liver
6
Q
What is the normal value for serum AST at 37 degrees C?
A
5-35 IU/L
7
Q
Which anticoagulant should NOT be used for urease testing?
A
sodium fluoride
8
Q
What is the normal percentage for the CK-MB isoenzyme?
A
less than 6 %
9
Q
What reagent is used in the measurement of uric acid?
A
phosphotunstic acid
10
Q
Creatinine clearance is used to assess the rate of what?
A
glomerular filtration
11
Q
Calculation for creatinine clearance if given urine volume and values for urine plasma.
A
CrCl=Ucr * Vu/ Pcr * T
12
Q
What additional information must be known for the calculation if the pt is an infant, young child, or adolescent?
A
body surface area
13
Q
What is the most common endogenous substance used to assess the glomerular filtration rate?
A
creatinine
14
Q
What is the most common exogenous substance used to assess the glomerular filtration rate?
A
inulin
15
Q
Serum creatine kinase is most often elevated in diseases of what tissue?
A
muscle
16
Q
Serum lipase levels are elevated to diseases of what organ?
A
pancreas
17
Q
Diacetyl monoxime reacts with what to produce a yellow product?
A
urea
18
Q
What is uremia?
A
abnormal substances in the blood (urea in the blood)
19
Q
What is the normal value for CK in males at 37 degrees C?
A
15-160 IU/L
20
Q
Name 3 ways that can be used in the lab to measure the rate of an enzymatic reaction?
A
multiple point, kinectic, continuous monitoring point
21
Q
Define IU(international unit)
A
the quantity of enzyme that will catalyze the reaction of one micromole (mmol) of substrate per minute
22
Q
What is the peak absorbency of reduced NAD (NADH)?
A
340 nm
23
Q
The Jaffe reaction is used to measure what?
A
creatinine
24
Q
Which non-protein nitrogen component comprises the largest fraction of NPN in the blood?
A
urea/BUN
25
Which enzyme is useful in the detection of insecticide poisoning?
pseudocholinesterase
26
Low levels of which enzyme can cause a pt to be susceptible to prolonged apnea when exposed to certain types of anesthesia?
pseudocholinesterase
27
Increased levels of LD-4 and LD-5 are associated with what?
acute hepatic disease
28
Gout is caused by the deposition of _______in joints and other tissues?
uric acid
29
What is the clinical significance of a mildly elevated ALP in a teenager?
no significance
30
What is the normal ratio of BUN to creatine? Be able to suggest the value of one if you are given the value for the other
10:1 and 15:1
31
What enzyme is normally elevated during pregnancy?
alkaline phosphatase
32
L-tartrate is used in the specific assay of which enzyme?
prostatic acid phosphatase
33
Which isoenzyme is detectable within 4-6 hours after an MI?
CK-2 or CK-MB (muscle and brain)
34
Retention of BSP can be used to measure what organ's function?
liver
35
What substrate and coenzyme are required to measure ammonia?
alpha-ketoglutarate
| Co-enzyme NADH
36
What is the main way that ammonia levels are kept within normal limits?
synthesizes of urea from ammonia
37
Amylase is an enzyme that breaks down what?
starch
38
Why should hemolyzed specimens NOT be used for acid phosphatase?
RBC contain acid phosphatase, levels increase
39
Acid phosphatase is primarily associated with diseases of what?
prostate
40
What is the proper treatment of serum to be assayed for ACP?
acidified to a pH below 6
41
What is the substrate for alkaline phosphatase methods of analysis?
para-nitrophenolphosphase
42
In the urease method, urea is converted to what?
ammonium carbonate
43
Increased levels of serum alkaline phosphatase can indicate diseases of what?
bone or liver
44
The enzyme responsible for the reversible oxidation of lactic acid to pyruvic acid is what?
LD (lactate dehydrogonase)
45
In the creatine kinase reaction _______ is converted to _______
ATP
| ADP
46
What is the endpoint of purine metabolism in man
uric acid
47
Serum amylase might be expected to be increased in the diseases of what?
pancreas
48
Which enzyme can be used to establish the presence of semen?
acid phosphatase
49
Phenylketonuria (PKU) results from a deficiency in which enzyme?
phenylalanine hydroxylase
50
What is the substrate for the enzyme alanine aminotransferase (ALT)?
alanine and alpha-ketoglutamic acid
51
What is the source of urease used in enzymatic methods for the determination of BUN?
Jack Bean meal
52
What precaution must be taken with specimens to be used for blood ammonia determinations?
avoid ammonia forming in vitro (outside the body), placed on ice, correct tube, plasma, tested within 15 mins, kept closed because of atmospheric ammonia
53
What is the correct order of migration of the creatine kinase (CK) isoenzymes starting with the slowest?
- MM
- MB
- BB
54
What are the substrates for amylase in the dye-labeled substrate method?
starch and dye
55
In the creatine method, a color develops when creatinine combines with what?
alkaline picrate
56
The major isoenzymes of lactate dehydrogenase come from the _____ and ______?
heart
| liver
57
What is the principle of the enzymatic method for measurement of ammonia?
change in absorbance at 340 nm
-uses enzyme glutamate dehydrogonase and the substrate alpha ketoglutorate reaction is followed by a drecease in absorbance at 340 nm as NADPH is converted to NADP
58
Strenuous exercise can cause elevated what?
CK
59
What causes the BSP dye to form colorless to colored?
alkali medium
60
What would hemolysis do to the results of a lactate dehydrogenase(LD) measurement? How are the results affected if the specimen is frozen?
elevate results
| cannot freeze falsely decreased
61
What test can differentiate between liver and bone origin of an elevated alkaline phosphatase?
GGT
62
What is the best anticoagulant to use for plasma specimens to be tested for lactate dehydrogenase?
heparin
63
What is the order of migration for the isoenzymes of alkaline phosphatase (ALP)?
liver is the fastest, bone, placenta, intestinal
64
What is the characteristic change in the isoenzymes of lactate dehydrogenase (LD) that is seen in a myocardial infarction (ALP)?
LD1 is greater than LD2
| LD flip
65
Creatinine excretion correlates best with the what?
muscle mass
66
Which enzyme is the first to become elevated following an MI?
CK
67
Aspartate aminotransferase (AST) is elevated in diseases of what?
heart
68
In the performance of a creatinine clearance, when should the specimen for serum creatinine be collected in relation to the collection of the urine?
midway thru urine collection and not longer than 24 hrs before or after collection
69
For how long and at what temp should specimens for lactate dehydrogenase (LD) be stored?
2-3 days at room temp
70
What enzyme can be used in the detection of alcoholism and in the monitoring of pts in alcohol treatment centers?
GGT
71
What is the normal value for prostatic acid phosphatase (ACP)?
less than or equal to 2.1 ng/ml
72
Why are the creatinine levels in the serum not a good indicator of early renal damage?
values are not above upper limit of normal until 1/2 to 2/3 of renal function is abnormal
73
What is the composition of Nessler's reagent and for what test is it used?
double iodide of potassium/mercury
| BUN
74
Which has more liver specificity, alanine aminotransferase (ALT) or aspartate aminotransferase (AST)?
ALT is more specific
| AST is for heart
75
In which organs is the activity of creatine kinase (CK) the greatest?
brain, heart, and skeletal muscle
76
What is the main factor that determines how much the level of an enzyme in serum increases?
extent and severity of damage to its tissues or cells of origin
77
How does progressive muscular dystrophy affect AST and ALT levels?
increases AST and ALT levels
78
What is the normal value for serum amylase at 37 degrees C?
95-290 IU/l
79
What is the major creatine kinase (CK) isoenzyme of normal serum?
CK-MM
80
At what temp should serum CK specimens be stored?
4 degrees C refrigerated
81
What is the purpose of the PSP test and the p-aminohippurate test?
measure excretory capacity of the kidneys
82
To what class of enzymes do amylase and lipase belong?
hydrolase
83
What is the normal value for serum BUN?
8-26 mg/dl
84
What is the old name for AST?
SGOT(serum glutamic oxaloacetic transaminase)
85
What is the old name for CK?
CPK (creatine phosphokinase)
86
What two isoforms of CK are used for the early detection on an MI?
CK-MM/MB1
87
What are the main uses of ammonia measurements?
diagnose Reyes syndrome and hepatic coma
88
What happens to the creatinine clearance value in renal disease?
decreases
89
What is the normal range for total serum bilirubin?
0.2-1.0 mg%
90
In the Jendrassik-Grof method, what is the caffeine benzoate solubilizer used for?
...Solubilizes the water-insoluble fraction of bilirubin and will yield a total bilirubin value. Without it, the rxn will yield conjugated bilirubin only
91
A list of risk factors for coronary heart disease
```
...Smoking
Hypertension
Increased total cholesterol & LDL
Decreased HDL
Diabetes mellitus
Age
Obesity
Physical Inactivity
Family history of premature CHD
Left ventricular hypertrophy
```
92
List of biochemical markers for coronary heart disease
...Triglycerides
Lp(a)
Homocysteine
hs-CRP
93
List of the ideal characteristics of a cardiac marker
```
..Cardiac specific
Rises soon after infarction occurs
Elevated over a sustained period of time
Easy to measure analytically
Broad dynamic range for measurements
Quick turnaround of tests
Diagnostic utility verified by clinical studies
```
94
Which marker has been recognized for the earliest biochemical marker for AMI?
Myoglobin
95
What is the biggest disadvantage of troponin as a cardiac marker?
Remains in blood 7-10 days (can't detect new infarction within that time frame)
96
What is the most likely cause of prehepatic bilirubin?
Increased amount of bilirubin being presented to the liver, such as in acute or chronic hemolytic anemias
97
Why are high levels of bilirubin seen in infants?
infant deficiency of enzyme glucuronyl transferase (last to develop because most bili processing done by mother)
98
What precautions need to be taken when processing bilirubin?
Fasting specimen preferred
Hemolysis not acceptable
Keep away from light
99
ranges for total, conjugated, and un-conjugated biliruben
Total:
Conjugated:
Un-Conjugated:
100
prehepatic, hepatic, and posthepatic specific conditions of each
Prehepatic:
Hepatic:
Posthepatic:
