Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CLINICAL CHEM > Enzymes > Flashcards

Enzymes Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

AST formerly know as

A

serum glutamate oxaloacetate transaminase (SGOT)

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

AST transfers an amino group between aspartate and alpha-keto acids with the formation of ________ and _________

A

oxaloacetate and glutamate

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

AST Coenzyme

A

Pyridoxal phosphate (active form of Vitamin B6)

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

isoenzyme fractions of AST

A
  • cytoplasm AST
  • mitochondria AST
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which isoenzyme fraction of AST is predominant form in serum

A

cytoplasm AST

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

AST Major tissue source

A

cardiac tissue, liver and skeletal muscle

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

AST Other sources

A

kidney, pancreas and RBC

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

Serum AST Determination (ERBA)N principle

A

Karmen method

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

L- Aspartate + 2-oxaloacetate – (___)—> _________ + L-Glutamate

________ + NADH —(___)—> _________ + NAD+

A

AST, Oxaloacetate, Oxaloacetate, MDH, Malate

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

AST normal values

A

5-37 U/L

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

ALT Formerly known as

A

serum glutamate pyruvate transaminase (SGPT)

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

ALT Coenzyme

A

Pyridoxal phosphate (active form of Vitamin B6)

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

ALT Transfers an amino group from alanine to alpha ketoglutarate with the formation of _____ and _____

A

glutamate and pyruvate

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

More liver-specific than AST

A

ALT

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

ALT Major tissue source

A

Liver

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

ALT other sources

A

kidney, pancreas, RBCs, heart, skeletal muscle and lungs

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

AST levels begin to rise

A

6-8 hrs

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

peak AST levels

A

24 hrs

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

AST returns to normal levels

A

within 5 days

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

AST clinical significance

A

1.Evaluation of myocardial infarction, hepatocellular disorders and skeletal muscle involvement
2. Chronic disorders of the liver with progressive damage
3.Monitoring therapy with potentially hepatotoxic drugs

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

ALT Clinical significance

A

▪ Hepatic disorders
▪ Markedly increased concentration on acute inflammatory conditions than AST
▪ Monitors the course of liver treatment and the effects of drug therapy
▪ Screen blood donors (sign of viral hepatitis)
▪ More sensitive and specific in screening for posttransfusion hepatitis or occupational toxic exposure than AST

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

AST and ALT highest increase of transferases is seen

A

Acute hepatitis

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

AST and ALT 20x increase in transferases

A

Severe viral or toxic hepatitis

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

AST and ALT Moderate increase

A

chronic hepatitis, hepatic cancer and infectious mononucleosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

AST and ALT Slight increase

A

hepatic cirrhosis, alcoholic cirrhosis, obstructive jaundice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

AST and ALT Markedly increase:

A

necrotic jaundice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

AST and ALT not elevated or may be low due to massive liver destruction

A

End-stage cirrhosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Serum ALT Determination (ERBA) principle

A

Coupled Enzymatic reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

L- Alanine + 2-Oxoglutarate —-(___)—> ______ + L-Glutamate
________ -> + NADH — (___)—> _______ + NAD+

A

ALT, Pyruvate, Pyruvate, LDH, L-Lactate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

ALT Normal values

A

6-37 U/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

GGT aka

A

gamma glutamyl transamine peptidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

GGT Major source

A

epithelial cells lining biliary ducts and canaliculi of hepatocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

GGT substrate

A

gamma-glutamyl-p-nitroanilide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

GGT Minor source

A

kidney, prostate and pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

GGT methods

A

Szass, Rosalki & Tarrow; Orlowski

36
Q

GGT Reference value

A

Female: 5-30 U/L
Male: 6-45 U/L

37
Q

GGT Clinical Significance:

A

▪Sensitive indicator of alcoholism (occult alcoholism)
▪Most sensitive marker for acute alcoholic hepatitis
▪Useful in monitoring the effects of abstention from alcohol
▪Useful in differentiating the source of increased ALP levels

38
Q

GGT Elevated in

A
  1. Hepatobiliary disorders (biliary tract obstruction)
  2. Pancreatitis and prostatic disorders
  3. Individuals undergoing warfarin, phenobarbital and phenytoin therapies
39
Q

Catalyzes the hydrolysis of various phosphomonoesters at an alkaline pH

A

ALP

40
Q

A nonspecific enzyme that liberates inorganic phosphate from an organic phosphate ester with concomitant production of an alcohol

A

ALP

41
Q

ALP Activator

A

Mg2+

42
Q

ALP Tissue source

A

intestine, liver (sinusoidal and bile canalicular membrane), bone (osteoblasts), spleen, placenta and kidney

43
Q

ALP elevated

A

Hepatobiliary disorders, Bone Disorders, Pregnancy

44
Q

Due to increased enzyme synthesis induced by cholestasis

A

Hepatobiliary disorders

45
Q

an interruption in the flow of bile due to obstruction of bile ducts or excretory failure of hepatocytes with accumulation of bile
constituents in the blood

A

cholestasis

46
Q

aka osteitis deformans (abnormally increased bone breakdown and regrowth); highest elevation of ALP activity

A

Paget’s disease

47
Q

softening of bones due to Vit. D deficiency

A

Osteomalacia

48
Q

ALP low levels

A

inherited hypophosphatasia (HPP)

49
Q

a result of the absence of the bone isoenzyme and results in inadequate bone calcification

A

inherited hypophosphatasia (HPP)

50
Q

ALP Assay for enzymatic activity

A

Continuous-monitoring technique based on Bowers and McComb’s method

51
Q

ALP enzymatic activity allows the calculation of ALP activity based on the molar absorptivity of

A

p-nitrophenol

52
Q

ALP Reference values

A

AGE U/L
Males/Females 4-15 54-369
Males 20-50 53-128
≥60 56-119
Females 20-50 42-98
≥60 53-141E

53
Q

A hydrolase that catalyze the breakdown/hydrolysis of poly α-1,4-linked glucose (glycosidic bonds) polymers

A

Amylase (AMY)

54
Q

AMY Da

A

50,000 to 55,000

55
Q

smallest enzyme that is readily filtered by the kidneys and seen in urine

A

AMY

56
Q

2 types of AMY

A

α-amylase and β-amylase

57
Q

cleaves maltose; Serum amylase from the major tissue sources - salivary glands (ptyalin) and pancreas

A

α-amylase

58
Q

present in yeasts, molds, bacteria and plants (seeds)

A

β-amylase

59
Q

AMY Activators

A

Ca2+ and Cl-

60
Q

AMY degree of elevation can help in differential diagnosis of ________

A

acute pancreatitis

61
Q

AMY begins to rise

A

5 – 8 hours after onset

62
Q

AMY peak

A

24 hours after onset

63
Q

AMY returns to normal

A

Within 3 to 5 days

64
Q

AMY molecule combines with immunoglobulins forming a complex, too large to be filtered by urine, accumulates in the serum

A

Macroamylasemia

65
Q

Measures the disappearance of starch substrate

A

Amylclastic

66
Q

Saccharogenic test amount of __________ is proportional to AMY activity

A

reducing sugars

67
Q

Amyloclastic test ___________ is proportional to AMY concentration

A

Decrease in color (dark-blue due to starch-iodine complex)

68
Q

Classic reference method for AMY

A

Saccharogenic

69
Q

Saccharogenic is reported in

A

Somogyi units (mg of glucose released in 30 mins at 37°C)

70
Q

Chromogenic test ___________ solution is proportional to AMY activity

A

Increase in color intensity of the water-soluble dye-substrate

71
Q

Coupling of several enzyme systems to monitor amylase activity

A

Continuous monitoring

72
Q

AMY test where Change in absorbance of NAD+ at 340 nm is measured

A

Continuous monitoring

73
Q

AMY Reference values and conversion factor

A

Serum 28-100 U/L
Urine 1-15 U/h
CF: 1.85

74
Q

Catalyzes the hydrolysis of ester linkages of fats to produce alcohols and fatty acids

A

Lipase (LPS)

75
Q

Lipase substrate

A

must be an emulsion for reaction to occur

76
Q

Lipase accelerators

A

colipase and bile salt

77
Q

LPS tissue source

A

pancreas (primary), stomach and small intestine

78
Q

LPS diagnostic significance

A

More specific to pancreatic disorders than AMY
Remains elevated for ~8 days in acute pancreatitis, extent of elevation does not correlate to disease severity

Elevated in other intra-abdominal conditions but less frequent than serum AMY

Normal in conditions of salivary gland involvement

Useful in differentiating serum AMY elevation as a result of pancreatic vs. salivary involvement

79
Q

LPS isoenzyme ____ is the most clinically specific and sensitive

A

L2

80
Q

LPS Test: estimation of liberated fatty acids

A

Titrimetric method

81
Q

LPS Test: used olive oil as substrate (24-hr incubation)

A

Cherry-Crandall method

82
Q

substrate use is triolein (a purer form of TAG)

A

Titrimetric LPS Modified method

83
Q

LPS test simpler and faster

A

Turbidimetric methods:

84
Q

LPS test: uses coupled reactions with enzymes like peroxidase or glycerol kinase

A

Colorimetric

85
Q

LPS Reference value

A

Normal <38 U/L (37⁰C)

CLINICAL CHEM (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions