CLINICAL CHEMISTRY

1. Which of the following isolates individual wavelength of light?

monochromator

2. A photomultiplier tube may be described all the following EXCEPT?

Can be used with a chopper

3. Which type of photodetector has a linear array that responds to a specific wavelength resulting in a

complete UV/visible spectrum?

Photodiode array

4. When performing spectrophotometer quality control checks, what is the holmium oxide glass filter

used to assess?

Wavelength accuracy

5. For applications requiring UV radiation, which of the cuvets should be used?

Quartz

6. What feature distinguishes a double-beam spectrophotometer from a single-beam

spectrophotometer?

Compares sample and reagent blank absorbances simultaneously

7. Problems inherent in turbidimetry include all of the following EXCEPT:

Slight variations in temperature

8. Fluorometers are designed so that the path of the exciting light is at the right angle to the path of the

emitted light. What is the purpose of this design?

Prevent excitation light from reaching the detector

9. Which of the following represents a primary advantage of performing fluorometric over absorption

spectroscopic methods of analysis?

Increased specificity and increased sensitivity

10. Absorbance is defined as:

2 – Log % transmittance

11. Nephelometry is a method of assay based on the measurement of the light that is:

Scattered by particles in suspension

12. The atomic spectrophotometer must have which of the following components?

Atomizer

13. Most atomic absorption spectrophotometers incorporate a beam chopper. The purpose of this

component is to avoid errors caused by?

Stray light from the hollow cathode lamp

14. Which of the following instruments is used in the clinical laboratory to detect beta and gamma

emissions?

Scintillation counter

15. In an electrolytic cell, which of the following is the half-cell where reduction takes place?

Cathode

16. The function of the flame in atomic absorption spectrophotometry is to:

Disassociates the chemical bonds and form free, unexcited atoms

17. In potentiometry, which of the following is considered the standard electrode?

Hydrogen electrode

18. Mercury covered by a layer of mercurous chloride in contact with saturated potassium chlorine

solution is a description of which of the following types of electrodes?

Calomel

19. When measuring potassium with an ion-selective electrode by means of a liquid ion-exchange

membrane, what antibiotic will be incorporated into the membrane?

valinomycin

20. Which of the following methods allows for the separation of charged particles based on their rates

of migration in an electric field?

Electrophoresis

21. Which of the following techniques based on electro-osmotic flow?

Capillary electrophoresis

22. Which of the following is an electrophoretic technique employing a pH gradient that separates

molecules with similar isoelectric points?

isoelectric focusing

23. Which of the following chromatography systems may be described as having a stationary phase that

is liquid absorbed on particles packed in a column and a liquid moving phase that is pumped through a

column?

High-performance liquid

24. Ion-exchange chromatography separates solutes in a sample based on the:

Sign and magnitude of ionic exchange

25. Which of the following chromatography systems is characterized by a stationary phase of silica gel

on a piece of glass and a moving phase of liquid?

Thin-layer

26. Given the following information on a particular compound that has been visualized by means of thin-

layer chromatography, calculate the Rf of the compound:

**distance from origin to spot center =48mm

**distance from spot center to solvent front =93mm

**distance from origin to solvent front =141mm

0.34

27. To achieve the best levels of sensitivity and specificity, to what type of detector system could a gas

chromatograph be coupled?

Mass spectrometer

28. Which of the following instruments has a sample-introduction system, solvent-delivery system,

column, and detector as components?

High-performance liquid chromatograph

29. Automation in the laboratory offers the following advantages, EXCEPT?

Use of controls and standards become unnecessary

30. Which of the following is a disaccharide?

Glucose

31. What does hydrolysis of lactose yield?

Glucose and galactose

32. In what form in glucose stored in the muscle and liver?

Glycogen

33. Which of the following is NOT a reducing sugar?

Sucrose

34. Which of the following defines the term gycolysis?

Conversion of glucose into lactate or pyruvate

35. What is the glucose concentration in fasting whole blood?

Less than the concentration in plasma and serum

36. Of the following glucose levels, which would you expect to result in glucose in the urine?

225 mg/dl

37. which of the following is a characteristic of type I diabetes mellitus?

- Low blood insulin levels

- Ketosis often accompanies hyperglycemia

- High frequency of autoantibodies to islet cells

38. All of the following are characteristics of type II diabetes mellitus EXCEPT?

It requires insulin therapy to control hyperglycemia

39. What effect if any would be expected when the secretion of epinephrine is stimulated by physical or

emotional stress?

Increase blood glucose level

40. If analysis cannot be done immediately, the serum specimen is generally stored at:

2-8 0C

41. All of the following results are diagnostic of diabetes mellitus EXCEPT?

Urine glucose at normal level

42. Select the appropriate reference range for fasting blood glucose?

65-110mg/dl (3.61-6.11 mmol/L)

43. In preparing a patient for an oral glucose tolerance test (OGTT), all of the following are done

EXCEPT?

Carbohydrate intake must be below 150 g/day for 3 days prior to test

44. Which of the following results would be classified as impaired glucose tolerance?

1 hr. serum glucose 2 hr. serum glucose

215 mg/dl 150 mg/dl

45. Which tests may be performed to assess the average plasma glucose level that an individual

maintained during a previous 6-8 week period?

Glycosylated hemoglobin

46. An individual has a blood drawn for glucose analysis as part of an oral glucose tolerance test (OGTT),

and the following results were obtained: fasting blood glucose = 120 mg/dl; 2-hours postload glucose =

225 mg/dl. These results are indicative of what state?

Diabetes mellitus

47. A 32-year-old pregnant woman has a gestational diabetes mellitus screening test performed at 26

weeks gestation. Her serum glucose is 150 mg/dl at 1 hour. What should occur next?

This is suspicious of diabetes; an oral glucose tolerance test should be performed

48. In monitoring complications of diabetes, all the following analytes would commonly be measured

EXCEPT:

Serum bilirubin

49. The term “ketone bodies” refers to all of the following compounds EXCEPT:

Acetic acid

50. A blood specimen can be considered a fasting sample when the patient had:

No food 8-14 hours after suffer

51. Glucose oxidase oxidizes glucose to gluconic acid and:

H2O2

52. From glucose and ATP, hexokinase catalyzes formation of:

Glucose-6-phosphate

53. What is the preferred specimen for glucose analysis?

Serum

54. The hyperglycemic factor produced by the pancreas is:

Glucagon

55. The preferred screening test for diabetes in nonpregnant adults is measurement of:

Fasting plasma glucose

56. A factor, other than average plasma glucose values, that determines the glycosylated hemoglobin

level is:

Red blood cell life span

57. Which of the following is characterized by a deficiency of glucose-6-phosphate resulting in

hepatomegaly, lactic acidosis, and severe fasting hypoglycemia?

Type I - von Gierke’s disease

58. An individual has a serum glucose level of 110 mg/dl. What would be the approximate glucose

concentration in this patient’s cerebrospinal fluid?

66 mg/dl (60%-70%)

59. An organ important in carbohydrate metabolism is the:

Liver

60. Deficiency of galactose-1-phosphate uridyl transferase results in a syndrome called:

Galactosemia

Hexokinase is the reference method for measuring serum glucose. Gluconeogenesis refers to the

synthesis of gloucose from noncarbohydrate sources. Pancreatic amylase is the pancreatic enzyme

involve in the digestion of starch. Insulin functions to increase the cellular uptake of glucose. Glucose is

stored in the muscle and liver in the form of glycogen. In a spectrophotometer, a diffraction grating or

prism is used. Nephelometry is the measurement of the light scattered by small particles at an angle to

the beam incident on the cuvettes. The more voltage to the electrophoresis system, the more

movement of proteins. Glycogenolysis refers to the breakdown of glycogen to glucose for use as energy.

Glucose oxidase is the more specific enzyme test for glucose.