In absorption spectrophotometry:
A. Absorbance is directly proportional to transmittance
B. Percent transmittance is directly proportional to concentration
C. Percent transmittance is directly proportional to the light path length
D. Absorbance is directly proportional to concentration
D. Absorbance is directly proportional to concentration
Which formula correctly describes the relationship between absorbance and percent transmittance (%T)?
A. A = 2 - log %T
B. A = log T
C. A = -log %T
D. A = 2 - %T
A. A = 2 - log %T
Which photodetector is most sensitive to low levels of light?
A. Barrier layer cell
B. Photodiode
C. Diode array
D. Photomultiplier tube
D. Photomultiplier tube
What is the confirmatory method for measuring drugs of abuse?
A. HPLC
B. Enzyme-multiplied immunoassay technique (EMIT)
C. Gas chromatography with mass spectroscopy (GC-MS)
D. TLC
C. Gas chromatography with mass spectroscopy (GC-MS)
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
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 years
D. Requires insulin replacement to prevent ketosis
D. Requires insulin replacement to prevent ketosis
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
According to the ADA 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
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
Identify the enzyme deficiency responsible for type 1 glycogen storage disease (GSD1 or von Gierke disease).
A. Glucose-6-phosphatase
B. Glycogen phosphorylase
C. Glycogen synthetase
D. B-Glucosidase
A. Glucose-6-phosphatase
Select the lipoprotein fraction that carries most of the endogenous triglycerides.
A. VLDL
B. LDL
C. HDL
D. Chylomicrons
A. VLDL
Which apoprotein is inversely related to risk of coronary heart disease?
A. Apoprotein A-I
B. Apoprotein B-100
C. Apoprotein C-II
D. Apoprotein E4
A. Apoprotein A-I
What is the most appropriate procedure when a fasting lipid study of triglyceride, total cholesterol, HDL cholesterol, and LDL cholesterol tests are ordered?
A. 8 hours; nothing but water allowed
B. 10 hours; water, smoking, coffee, tea (no sugar or cream) allowed
C. 12 hours; nothing but water allowed
D. 16 hours; water, smoking, coffee, tea (no sugar or cream) allowed
C. 12 hours; nothing but water allowed
Following ultracentrifugation of plasma, which fraction correlates with pre-ß lipoprotein?
A. Very low-density lipoprotein (VLDL)
B. Low-density lipoprotein (LDL)
C. High-density lipoprotein (HDL)
D. Chylomicrons
A. Very low-density lipoprotein (VLDL)
Treatment recommendations for patients with coronary hear disease are based on the measurement of which analyte?
A. HDL cholesterol
B. Apo B-100
C. LDL cholesterol
D. Total cholesterol
C. LDL cholesterol
Which of the following hormones produces vasopressin?
A. Hypothalamus
B. Anterior Pituitary
C. Posterior Pituitary
D. Adrenal glands
A. Hypothalamus
Thyroid hormones are derived from the amino acid:
A. Phenylalanine
B. Methionine
C. Tyrosine.
D. Histidine
C. Tyrosine.
Which statement regarding thyroid hormones is true?
A. Circulating levels of T3 and T4 are about equal
B. T3 is about 10-fold more active than T4
C. The rate of formation of monoiodotyrosine and diodotyrosine is about equal
D. Most of the T3 present in plasma is from its direct release from thyroid storage sites
B. T3 is about 10-fold more active than T4
A patient has an elevated serum-free T3 and free T4 and undetectable TSH. What is the most likely cause of these results?
A. Primary hyperthyroidism
B. Secondary hyperthyroidism
C. Euthyroid with increased TBG
D. Euthyroid sick syndrome
A. Primary hyperthyroidism
The serum TSH level is almost absent in:
A. Primary hyperthyroidism
B. Primary hypothyroidism
C. Secondary hyperthyroidism
D. Euthyroid sick syndrome
A. Primary hyperthyroidism
Which of the following conditions is characterized by primary hyperaldosteronism caused by adrenal adenoma, carcinoma, or hyperplasia?
A. Cushing syndrome
B. Addison disease
C. Conn syndrome
D. Pheochromocytoma
C. Conn syndrome
Which is normally the most abundant corticosteroid hormone secreted by the adrenal cortex?
A. Cortisol
B. Dehydroepiandrosterone
C. Aldosterone
D. Corticosterone
A. Cortisol
Select the most appropriate single screening test for thyroid disease.
A. Free T4 index
B. Free T3
C. Free T4
D. TSH assay
D. TSH assay
Which of the following conditions will increase total T4 by increasing thyroxine-binding globulin (TBG)?
A. Acute illness
B. Anabolic steroid use
C. Nephrotic syndrome
D. Pregnancy or estrogens
D. Pregnancy or estrogens
