Clinical Chemistry- Glucose, Hbg,Iron and Bilirubin Flashcards by H. JG

Which of the following biochemical processes is
promoted by insulin?
A. Glycogenolysis
B. Gluconeogenesis
C. Lipolysis
D. Uptake of glucose by cells

D. Uptake of glucose by cells

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Which of the following hormones promotes
hyperglycemia?
A. Calcitonin
B. Growth hormone
C. Aldosterone
D. Renin

B. Growth hormone

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Which of the following is characteristic of
type 1 diabetes mellitus?
A. Requires an oral glucose tolerance test for
diagnosis
B. Is the most common form of diabetes mellitus
C. Usually occurs after age 40
D. Requires insulin replacement to prevent ketosis

D. Requires insulin replacement to prevent ketosis

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Which of the following is characteristic of
type 2 diabetes mellitus?
A. Insulin levels are consistently low
B. Most cases require a 3-hour oral glucose
tolerance test to diagnose
C. Hyperglycemia is often controlled without
insulin replacement
D. The condition is associated with unexplained
weight loss

C. Hyperglycemia is often controlled without
insulin replacement

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Which of the following results falls within the
diagnostic criteria for diabetes mellitus?
A. Fasting plasma glucose of 120 mg/dL
B. Two-hour postprandial plasma glucose of
160 mg/dL
C. Two-hour plasma glucose of 180 mg/dL
following a 75 g oral glucose challenge
D. Random plasma glucose of 250 mg/dL and
presence of symptoms

D. Random plasma glucose of 250 mg/dL and
presence of symptoms

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Select the most appropriate adult reference range
for fasting blood glucose.
A. 40–105 mg/dL (2.22–5.82 mmol/L)
B. 60–140 mg/dL (3.33–7.77 mmol/L)
C. 65–99 mg/dL (3.61–5.50 mmol/L)
D. 75–150 mg/dL (4.16–8.32 mmol/L)

C. 65–99 mg/dL (3.61–5.50 mmol/L)

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When preparing a patient for an oral glucose
tolerance test (OGTT), which of the following
conditions will lead to erroneous results?
A. The patient remains ambulatory for 3 days prior
to the test
B. Carbohydrate intake is restricted to below
150 g/day for 3 days prior to test
C. No food, coffee, tea, or smoking is allowed
8 hours before and during the test
D. Administration of 75 g of glucose is given to an
adult patient following a 10–12-hour fast

B. Carbohydrate intake is restricted to below
150 g/day for 3 days prior to test

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Which of the following 2-hour glucose challenge
results would be classified as impaired glucose
tolerance (IGT)?
Two-hour serum glucose:
A. 130 mg/dL
B. 135 mg/dL
C. 150 mg/dL
D. 204 mg/dL

C. 150 mg/dL

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Which statement regarding gestational diabetes
mellitus (GDM) is correct?
A. Is diagnosed using the same oral glucose
tolerance criteria as in nonpregnancy
B. Converts to diabetes mellitus after pregnancy
in 60%–75% of cases
C. Presents no increased health risk to the fetus
D. Is defined as glucose intolerance originating
during pregnancy

D. Is defined as glucose intolerance originating
during pregnancy

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Which of the following findings is characteristic
of all forms of clinical hypoglycemia?
A. A fasting blood glucose value below 55 mg/dL
B. High fasting insulin levels
C. Neuroglycopenic symptoms at the time of low
blood sugar
D. Decreased serum C peptide

C. Neuroglycopenic symptoms at the time of low blood sugar

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Which statement regarding glycated (glycosylated)
Hgb (G-Hgb) is true?
A. Has a sugar attached to the C-terminal end of
the β chain
B. Is a highly reversible aminoglycan
C. Reflects the extent of glucose regulation in the
8- to 12-week interval prior to sampling
D. Will be abnormal within 4 days following an
episode of hyperglycemia

C. Reflects the extent of glucose regulation in the
8- to 12-week interval prior to sampling

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What is the American Diabetes Association
recommended cutoff value for adequate control of
blood glucose in diabetics as measured by glycated
hemoglobin?
A. 5%
B. 6.5%
C. 9.5%
D. 11%

B. 6.5%

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Which statement regarding measurement of Hgb
A1c is true?
A. Levels do not need to be done fasting
B. Both the labile and stable Hgb A1c fractions are
measured
C. Samples should be measured within 2 hours of
collection
D. The assay must be done by chromatography

A. Levels do not need to be done fasting

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Which stationary phase is used for the
measurement of hemoglobin A1c by high
performance liquid chromatography?
A. Octadecylsilane (C18)
B. Cation exchanger
C. Anion exchanger
D. Polystyrene divinylbenzene

B. Cation exchanger

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Evaluate the following chromatogram of a
whole-blood hemolysate, and identify the cause
and best course of action.
A. Result is not reportable because hemoglobin F
is present and interferes
B. The result is not reportable because
hemoglobin C is present and interferes
C. The result is not reportable because labile
hemoglobin A1c is present
D. The result is reportable; neither hemoglobin F
or C interfere

D. The result is reportable; neither hemoglobin F
or C interfere

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Which statement best describes the use of the
Hgb A1C test?

A. Should be used for monitoring glucose control
only
B. May be used for both diagnosis and monitoring
C. Should be used only to monitor persons with
type 1 diabetes
D. May be used only to monitor persons with
type 2 diabetes

B. May be used for both diagnosis and monitoring

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According to American Diabetes Association
criteria, which result is consistent with a diagnosis
of impaired fasting glucose?
A. 99 mg/dL
B. 117 mg/dL
C. 126 mg/dL
D. 135 mg/dL

B. 117 mg/dL

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What is the recommended cutoff for the early
detection of chronic kidney disease in diabetics
using the test for microalbuminuria?
A. >30 mg/g creatinine
B. >80 mg/g creatinine
C. >200 mg/g creatinine
D. >80 mg/L

A. >30 mg/g creatinine

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In addition to measuring blood glucose, Hgb A1c,
and microalbumin, which test should be done on
diabetic persons once per year?
A. Urine glucose
B. Urine ketones
C. Plasma fructosamines
D. Estimated glomerular filtration rate

D. Estimated glomerular filtration rate

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Which testing situation is appropriate for the use
of point-of-care whole-blood glucose methods?
A. Screening for type 2 diabetes mellitus
B. Diagnosis of diabetes mellitus
C. Monitoring of blood glucose control in type 1
and type 2 diabetics
D. Monitoring diabetics for hyperglycemic
episodes only

C. Monitoring of blood glucose control in type 1
and type 2 diabetics

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Which of the following is the reference method
for measuring serum glucose?
A. Somogyi–Nelson
B. Hexokinase
C. Glucose oxidase
D. Glucose dehydrogenase

B. Hexokinase

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Polarographic methods for glucose analysis are
based upon which principle of measurement?
A. Nonenzymatic oxidation of glucose
B. The rate of O2 depletion
C. Chemiluminescence caused by formation of
adenosine triphosphate (ATP)
D. The change in electrical potential as glucose is
oxidized

B. The rate of O2 depletion

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In addition to polarography, what other
electrochemical method can be used to
measure glucose in plasma?
A. Conductivity
B. Potentiometry
C. Anodic stripping voltammetry
D. Amperometry

D. Amperometry

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Select the enzyme that is most specific for
β-D-glucose.
A. Hexokinase
B. G-6-PD
C. Phosphohexisomerase
D. Glucose oxidase

D. Glucose oxidase

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25. Select the coupling enzyme used in the hexokinase method for glucose. A. Glucose-6-phosphate dehydrogenase B. Peroxidase C. Glucose dehydrogenase D. Glucose-6-phosphatase

A. Glucose-6-phosphate dehydrogenase

26. Which glucose method is subject to falsely low results caused by ascorbate? A. Hexokinase B. Glucose dehydrogenase C. Trinder glucose oxidase D. Polarography

C. Trinder glucose oxidase

27. Which of the following is a potential source of error in the hexokinase method? A. Galactosemia B. Hemolysis C. Sample collected in fluoride D. Ascorbic acid

B. Hemolysis

28. Which statement about glucose in cerebrospinal fluid (CSF) is correct? A. Levels below 40 mg/dL occur in septic meningitis, cancer, and multiple sclerosis B. CSF glucose is normally the same as the plasma glucose level C. Hyperglycorrhachia is caused by dehydration D. In some clinical conditions, the CSF glucose can be greater than the plasma glucose

A. Levels below 40 mg/dL occur in septic meningitis, cancer, and multiple sclerosis

29. In peroxidase-coupled glucose methods, which reagent complexes with the chromogen? A. Nitroprusside B. Phenol C. Tartrate D. Hydroxide

B. Phenol

30. Point-of-care-tests (POCTs) for whole-blood glucose monitoring are based mainly on the use of: A. Glucose oxidase as the enzyme B. Amperometric detection C.Immunochromatography D. Peroxidase coupling reactions

B. Amperometric detection

31. What effect does hematocrit have on POCT tests for whole-blood glucose monitoring? A. Low hematocrit decreases glucose readings on all devices B. High hematocrit raises glucose readings on all devices C. The effect is variable and dependent on the enzyme/coenzyme system D. Low hematocrit raises readings and high hematocrit lowers readings unless corrected

D. Low hematocrit raises readings and high hematocrit lowers readings unless corrected

32. Which of the following is classified as a mucopolysaccharide storage disease? A. Pompe’s disease B. von Gierke disease C. Hers’ disease D. Hurler’s syndrome

D. Hurler’s syndrome

33. Identify the enzyme deficiency responsible for type 1 glycogen storage disease (von Gierke’s disease). A. Glucose-6-phosphatase B. Glycogen phosphorylase C. Glycogen synthetase D. β-Glucosidase

A. Glucose-6-phosphatase

34. Which of the following abnormal laboratory results is found in von Gierke’s disease? A. Hyperglycemia B. Increased glucose response to epinephrine administration C. Metabolic alkalosis D. Hyperlipidemia

D. Hyperlipidemia

35. The D-xylose absorption test is used for the differential diagnosis of which two diseases? A. Pancreatic insufficiency from malabsorption B. Primary from secondary disorders of glycogen synthesis C. Type 1 and type 2 diabetes mellitus D. Generalized from specific carbohydrate intolerance

A. Pancreatic insufficiency from malabsorption

36. Which of the following statements about carbohydrate intolerance is true? A. Galactosemia results from deficiency of galactose-1-phosphate (galactose-1-PO4) uridine diphosphate transferase B. Galactosemia results in a positive glucose oxidase test for glucose in urine C. Urinary galactose is seen in both galactosemia and lactase deficiency D. A galactose tolerance test is used to confirm a diagnosis of galactosemia

A. Galactosemia results from deficiency of galactose-1-phosphate (galactose-1-PO4) uridine diphosphate transferase

37. Which of the following statements regarding iron metabolism is correct? A. Iron absorption is decreased by alcohol ingestion B. Normally, 40%–50% of ingested iron is absorbed C. The daily requirement is higher for pregnant and menstruating women D. Absorption increases with the amount of iron in the body stores

C. The daily requirement is higher for pregnant and menstruating women

38. Which of the following processes occurs when iron is in the oxidized (Fe3+) state? A. Absorption by intestinal epithelium B. Binding to transferrin and incorporation into ferritin C. Incorporation into protoporphyrin IX to form functional heme D. Reaction with chromogens in colorimetric assays

B. Binding to transferrin and incorporation into ferritin

39. Which of the following is associated with low serum iron and high total iron-binding capacity (TIBC)? A. Iron deficiency anemia B. Hepatitis C. Nephrosis D. Noniron deficiency anemias

A. Iron deficiency anemia

40. Which condition is associated with the lowest percent saturation of transferrin? A. Hemochromatosis B. Anemia of chronic infection C. Iron deficiency anemia D. Noniron deficiency anemia

C. Iron deficiency anemia

41. Which condition is most often associated with a high serum iron level? A. Nephrosis B. Chronic infection or inflammation C. Polycythemia vera D. Noniron deficiency anemias

D. Noniron deficiency anemias

42. Which of the following is likely to occur first in iron deficiency anemia? A. Decreased serum iron B. Increased TIBC C. Decreased serum ferritin D. Increased transferrin

C. Decreased serum ferritin

43. Which formula provides the best estimate of serum TIBC? A. Serum transferrin in mg/dL × 0.70 = TIBC (μg/dL) B. Serum transferrin in mg/dL × 1.43 = TIBC (μg/dL) C. Serum iron (μg/dL)/1.2 + 0.06 = TIBC (μg/dL) D. Serum Fe (μg/dL) × 1.25 = TIBC (μg/dL)

B. Serum transferrin in mg/dL × 1.43 = TIBC (μg/dL)

44. Which statement regarding the diagnosis of iron deficiency is correct? A. Serum iron levels are always higher at night than during the day B. Serum iron levels begin to fall before the body stores become depleted C. A normal level of serum ferritin rules out iron deficiency D. A low serum ferritin is diagnostic of iron deficiency

D. A low serum ferritin is diagnostic of iron deficiency

45. Which statement about iron methods is true? A. Interference from Hgb can be corrected by a serum blank B. Colorimetric methods measure binding of Fe2+ to a ligand such as ferrozine C. Atomic absorption is the method of choice for measurement of serum iron D. Serum iron can be measured by potentiometry

B. Colorimetric methods measure binding of Fe2+ to a ligand such as ferrozine

46. Which of the following statements regarding the TIBC assay is correct? A. All TIBC methods require addition of excess iron to saturate transferrin B. All methods require the removal of unbound iron C. Measurement of TIBC is specific for transferrinbound iron D. The chromogen used must be different from the one used for measuring serum iron

A. All TIBC methods require addition of excess iron to saturate transferrin

47. Which of the following statements regarding the metabolism of bilirubin is true? A. It is formed by hydrolysis of the α methene bridge of urobilinogen B. It is reduced to biliverdin prior to excretion C. It is a by-product of porphyrin production D. It is produced from the destruction of RBCs

D. It is produced from the destruction of RBCs

48. Bilirubin is transported from reticuloendothelial cells to the liver by: A. Albumin B. Bilirubin-binding globulin C. Haptoglobin D. Transferrin

A. Albumin

49. In the liver, bilirubin is conjugated by addition of: A. Vinyl groups B. Methyl groups C. Hydroxyl groups D. Glucuronyl groups

D. Glucuronyl groups

50. Which enzyme is responsible for the conjugation of bilirubin? A. β-Glucuronidase B. UDP-glucuronyl transferase C. Bilirubin oxidase D. Biliverdin reductase

B. UDP-glucuronyl transferase

51. The term δ-bilirubin refers to: A. Water-soluble bilirubin B. Free unconjugated bilirubin C. Bilirubin tightly bound to albumin D. Direct-reacting bilirubin

C. Bilirubin tightly bound to albumin

52. Which of the following processes is part of the normal metabolism of bilirubin? A. Both conjugated and unconjugated bilirubin are excreted into the bile B. Methene bridges of bilirubin are reduced by intestinal bacteria forming urobilinogens C. Most of the bilirubin delivered into the intestine is reabsorbed D. Bilirubin and urobilinogen reabsorbed from the intestine are mainly excreted by the kidneys

B. Methene bridges of bilirubin are reduced by intestinal bacteria forming urobilinogens

53. Which of the following is a characteristic of conjugated bilirubin? A. It is water soluble B. It reacts more slowly than unconjugated bilirubin C. It is more stable than unconjugated bilirubin D. It has the same absorbance properties as unconjugated bilirubin

A. It is water soluble

54. Which of the following statements regarding urobilinogen is true? A. It is formed in the intestines by bacterial reduction of bilirubin B. It consists of a single water-soluble bile pigment C. It is measured by its reaction with p-aminosalicylate D. In hemolytic anemia, it is decreased in urine and feces

A. It is formed in the intestines by bacterial reduction of bilirubin

55. Which statement regarding bilirubin metabolism is true? A. Bilirubin undergoes rapid photo-oxidation when exposed to daylight B. Bilirubin excretion is inhibited by barbiturates C. Bilirubin excretion is increased by chlorpromazine D. Bilirubin is excreted only as the diglucuronide

A. Bilirubin undergoes rapid photo-oxidation when exposed to daylight

56. Which condition is caused by deficient secretion of bilirubin into the bile canaliculi? A. Gilbert’s disease B. Neonatal hyperbilirubinemia C. Dubin–Johnson syndrome D. Crigler–Najjar syndrome

C. Dubin–Johnson syndrome

57. In hepatitis, the rise in serum conjugated bilirubin can be caused by: A. Secondary renal insufficiency B. Failure of the enterohepatic circulation C. Enzymatic conversion of urobilinogen to bilirubin D. Extrahepatic conjugation

B. Failure of the enterohepatic circulation

58. Which of the following is a characteristic of obstructive jaundice? A. The ratio of direct to total bilirubin is greater than 1:2 B. Conjugated bilirubin is elevated, but unconjugated bilirubin is normal C. Urinary urobilinogen is increased D. Urinary bilirubin is normal

A. The ratio of direct to total bilirubin is greater than 1:2

59. Which of the following would cause an increase in only the unconjugated bilirubin? A. Hemolytic anemia B. Obstructive jaundice C. Hepatitis D. Hepatic cirrhosis

A. Hemolytic anemia

60. Which form of hyperbilirubinemia is caused by an inherited absence of UDP-glucuronyl transferase? A. Gilbert’s syndrome B. Rotor syndrome C. Crigler–Najjar syndrome D. Dubin–Johnson syndrome

C. Crigler–Najjar syndrome

61. Which statement regarding total and direct bilirubin levels is true? A. Total bilirubin level is a less sensitive and specific marker of liver disease than the direct level B. Direct bilirubin exceeds 3.5 mg/dL in most cases of hemolytic anemia C. Direct bilirubin is normal in cholestatic liver disease D. The ratio of direct to total bilirubin exceeds 0.40 in hemolytic anemia

A. Total bilirubin level is a less sensitive and specific marker of liver disease than the direct level

62. Which statement best characterizes serum bilirubin levels in the first week following delivery? A. Serum bilirubin 24 hours after delivery should not exceed the upper reference limit for adults B. Jaundice is usually first seen 48–72 hours postpartum in neonatal hyperbilirubinemia C. Serum bilirubin above 5.0 mg/dL occurring 2–5 days after delivery indicates hemolytic or hepatic disease D. Conjugated bilirubin accounts for about 50% of the total bilirubin in neonates

B. Jaundice is usually first seen 48–72 hours postpartum in neonatal hyperbilirubinemia

63. Which form of jaundice occurs within days of delivery and usually lasts 1–3 weeks, but is not due to normal neonatal hyperbilirubinemia or hemolytic disease of the newborn? A. Gilbert syndrome B. Lucey –Driscoll syndrome C. Rotor syndrome D. Dubin–Johnson syndrome

B. Lucey –Driscoll syndrome

64. A lab measures total bilirubin by the Jendrassik–Grof bilirubin method with sample blanking. What would be the effect of moderate hemolysis on the test result? A. Falsely increased due to optical interference B. Falsely increased due to release of bilirubin from RBCs C. Falsely low due to inhibition of the diazo reaction by hemoglobin D. No effect due to correction of positive interference by sample blanking

C. Falsely low due to inhibition of the diazo reaction by hemoglobin

65. Which reagent is used in the Jendrassik–Grof method to solubilize unconjugated bilirubin? A. 50% methanol B. N-butanol C. Caffeine D. Acetic acid

C. Caffeine

66. Which statement about colorimetric bilirubin methods is true? A. Direct bilirubin must react with diazo reagent under alkaline conditions B. Most methods are based upon reaction with diazotized sulfanilic acid C. Ascorbic acid can be used to eliminate interference caused by Hgb D. The color of the azobilirubin product is independent of pH

B. Most methods are based upon reaction with diazotized sulfanilic acid

67. Which statement regarding the measurement of bilirubin by the Jendrassik–Grof method is correct? A. The same diluent is used for both total and direct assays to minimize differences in reactivity B. Positive interference by Hgb is prevented by the addition of HCl after the diazo reaction C. The color of the azobilirubin product is intensified by the addition of ascorbic acid D. Fehling’s reagent is added after the diazo reaction to reduce optical interference by hemoglobin

D. Fehling’s reagent is added after the diazo reaction to reduce optical interference by hemoglobin

68. A neonatal bilirubin assay performed at the nursery by bichromatic direct spectrophotometry is 4.0 mg/dL. Four hours later, a second sample assayed for total bilirubin by the Jendrassik–Grof method gives a result of 3.0 mg/dL. Both samples are reported to be hemolyzed. What is the most likely explanation of these results? A. Hgb interference in the second assay B. δ-Bilirubin contributing to the result of the first assay C. Falsely high results from the first assay caused by direct bilirubin D. Physiological variation owing to premature hepatic microsomal enzymes

A. Hgb interference in the second assay

69. In the enzymatic assay of bilirubin, how is measurement of both total and direct bilirubin accomplished? A. Using different pH for total and direct assays B. Using UDP glucuronyl transferase and bilirubin reductase C. Using different polarity modifiers D. Measuring the rate of absorbance decrease at different time intervals

A. Using different pH for total and direct assays

70. What is the principle of the transcutaneous bilirubin assay? A. Conductivity B. Amperometric inhibition C. Multiwavelength reflectance photometry D. Infrared spectroscopy

C. Multiwavelength reflectance photometry

Clinical Chemistry- Glucose, Hbg,Iron and Bilirubin Flashcards

(70 cards)