Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MT6317 > UNIT X: Urea Nitrogen Determination > Flashcards

UNIT X: Urea Nitrogen Determination Flashcards

(72 cards)

Start Studying
1
Q

Major excretory product of protein metabolism

A

Urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

T or F: Urea is formed in the kidney

A

F

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Urea is also known as

A

Carbamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Chemical formula of urea

A

CO(NH2)2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

T or F: Urea has 2 -NH2 groups joined by a carbonyl functional group

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

T or F: Urea determination is also known as Blood Urea Nitrogen

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Urea determination is a common blood chemistry test ordered by physicians to assess renal function, together with ______ (another NPN)

A

creatinine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Enzymatic method uses this enzyme

A

Urease or Urea Amidohydrolase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Most frequently used method in clinical laboratories

A

Enzymatic method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T or F: Enzymatic method allows the hydrolysis of urea in the sample, and the ammonium ion (NH4+) produced in the reaction is quantified

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Most common enzymatic method

A

GLDH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

GLDH stands for

A

Glutamate dehydrogenase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Indicator dye measures urea by ______ ______ using a pH indicator

A

color change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T or F: GLDH uses liquid reagents, multilayer film formats, and reagent strips

A

F

Indicator Dye uses these

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Conductimetric method uses an ________ to measure the rate of increase in conductivity

A

electrode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

This is the reference method

A

IDMS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

IDMS uses ________-labeled compounds for quantification

A

isotopically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

IDMS stands for

A

Isotope Dilution Mass Spectrometry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Direct/Indirect: Measures a chromogen produced directly from Urea

A

Direct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Direct/Indirect: Involves heating he sample with diacetyl monoxime in acidic solution

A

Direct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Direct/Indirect: Involves digesting the urea with urease to form ammonia

A

Indirect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Direct/Indirect: Lacks sensitivity, is time-consuming and hazardous

A

Direct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

T or F: GLDH is an example of a Direct method

A

F

Indirect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

T or F: Only the nitrogen part of Urea is quantitated in BUN

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
The biosynthesis of urea from ammonia is exclusively carried out by the _________ ________
hepatic enzymes
26
___% of urea is reabsorbed
40
27
Principle behind Urease/GLDH Method
Enzymatic + UV + Kinetic
28
T or F: In GLDH Method, absorbance is read twice
T
29
T or F: Decrease in absorbance at 430 nm is proportional to the concentration of Urea
F 340 nm
30
Urease hydrolyzes Urea to form _______ and ______
ammonia ; carbonate
31
Glutamate dehydrogenase forms these 3 products
Glutamate, NAD, and water
32
In GLDH method, ________ and _______ are converted to glutamate
ammonia ; a-oxoglutarate
33
T or F: The oxidation of NADH to NAD+ causes a decrease in absorbance in the reaction
T
34
This method is best used as a kinetic measurement
GLDH
35
This method is the most specific and rapid
Conductometric
36
Specimen used in Urea determination (3)
Serum Plasma Timed Urine Specimen
37
These additives should be avoided if plasma is collected for Urea determination
Sodium citrate Sodium fluoride
38
T or F: Urine is stable up to 5 days if stored at 2-8C
F 4 days only
39
Sodium citrate and sodium fluoride are inhibitors of ______
urease
40
T or F: Fasting is required in Urea determination
F
41
Reagent 1
Tris buffer (7.6) ADP alpha-ketoglutarate urease glutamate dehydrogenase sodium azide
42
Reagent 2
NADH sodium azide
43
T or F: Sodium azide irritates eyes and skin
T
44
Concentration of Standard Urea
50 mg/dL or 8.33 mmol/L
45
T or F: Lithium heparinized plasma can be used
T
46
Ellitrol I is the _______ Control; while Ellitrol II is the _______ Control
Normal ; Pathologic
47
Type of test tube to be used
Kahn test tube
48
Ratio of R1 to R2
1:1
49
Volume of Reagent 1A
1.0 mL
50
T or F: Reagent is added to the test tubes before the sample
F Sample first
51
T or F: When delivering the sample, touch the pipet directly to the bottom of the tube
T
52
T or F: Spectrophotometer is set up prior to adding the sample to the test tube
F after adding the sample and prior to adding the reagent
53
T or F: When delivering the reagent, touch the pipet directly to the bottom of the tube
F only to the side of the tube
54
Cover the test tube with parafilm and invert the tubes _____ times
2-3
55
Read and record the absorbance as A1 at ___ seconds
27
56
Read and record the absorbance as A2 at ___ seconds
90
57
Wavelength required
340 nm
58
Optical path required
1 cm
59
Temperature required
37 C
60
Assay should be read against ________ ______
distilled water
61
Formula for the change in absorbance
A1 - A2
62
T or F: BUN value is higher than Urea value
F lower (1:2)
63
Conversion factor for Urea mg/dL to BUN mg/dL
0.466
64
Conversion factor for BUN mg/dL to Urea mg/dL
2.14
65
Conversion factor for BUN mg/dL to Urea mmol/L
0.357
66
Reference interval for Plasma or Serum
Conventional: 6-20 mg/dL SI: 2.1-7.1 mmol/L
67
Reference interval for 24-hr urine
Conventional: 12-20 g/day SI: 0.43-0.71 mmol/day
68
Elevated urea concentration in blood
Azotemia
69
Uremia / Uremic Syndrome
Increased urea level accompanied by renal failure
70
T or F: Severe diarrhea can cause a decrease in the concentration of Urea
T
71
Range for normal control
13.3 - 17.7 mg/dL
72
Range for abnormal control
42.4 - 51.6 mg/dL

MT6317 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions