BOC Chemistry Practice Questions
Which of the following would cause erroneous oral glucose tolerance test (OGTT) results on a patient? - The patient remains ambulatory for 3 days prior to the test - No food, coffee, tea, or smoking is allowed 8 hours before and during the test - Carbohydrate intake is restricted to below 150 g/day for 3 days prior to the test - Administration of 75g of glucose is given to an adult patient following a 10-12 hour fast
Carbohydrate intake is restricted to below 150 g/day for 3 days prior to the test
Select the principle of the tablet test for bilirubin in urine or feces: - Chemical coupling of bile with diazonium salt to form a brown color - The liberation of oxygen by bile to oxidize orthotolidine to a blue-purple color - The reaction between bile and 2,4-dicholoronitrobenzene to a yellow color - Chemical coupling of bilirubin with a Diazonium salt to form a purple color
Chemical coupling of bilirubin with a Diazonium salt to form a purple color
Which lipid does not serve as a source of fuel, but can be converted to steroid hormones? - Fatty acids - Cholesterol - Triglycerides - Phospholipids
Cholesterol
What is the term used to describe a clinical syndrome caused by heart disease, represented by abnormal sodium and water retention and breathlessness, usually resulting in edema? - Acute myocardial infarction (AMI) - Angina - Congestive heart failure (CHF) - Myocardial ischemia
Congestive heart failure (CHF)
Which of the following tests would be useful in the assessment of glomerular filtration: - 24 hour urine protein - Creatinine clearance - PSP test - Urea clearance
Creatinine clearance
Which of the following would be indicative of partially compensated respiratory acidosis? - Increased pH, decreased PCO2, decreased bicarb - Decreased pH, decreased PCO2, decreased bicarb - Increased pH, increased PCO2, increased bicarb - Decreased pH, increased PCO2, increased bicarb
Decreased pH, increased PCO2, increased bicarb
A test for microalbuminuria is used most often to monitor patients with which of the following diseases or conditions? - Diabetes - Bacterial infection - Multiple myeloma - Hepatitis C
Diabetes
Hemoglobin A1c (HbA1c) percent can be used as an assay to diagnose which of the following conditions? - Diabetes - Cirrhosis - Myocardial infarction - Leukemia
Diabetes
Hypernatremia is associated with which of the following? - Burns - Diarrhea - Diabetes insipidus - Hypoaldosteronism
Diabetes insipidus
Which of the following is associated with hypernatremia? - Diabetes insipidus - Burns - Hyperaldosteronism - Diarrhea
Diabetes insipidus
Most common methods for measuring bilirubin are based on the reaction of bilirubin with: - Methyl alcohol - Neural salts - Bilirubin oxidase - Diazo reagent
Diazo reagent
Which of the following therapeutic drugs increases the force of myocardial muscle contraction? - Primidone - Cyclosporine - Digoxin - Disopyramide
Digoxin
Maltose, lactose, and sucrose are all: - Reducing substances - Oligosaccharides - Disaccharides - Monosaccharides
Disaccharides
In evaluating a patient who is exhibiting signs of drug toxicity, what must be considered? - If the concentration of the total drug is within the therapeutic limits, the concentration of the free drug cannot be toxic - If the drug has a wide therapeutic index, then it will not be toxic - A drug level cannot be toxic if the trough is within the published therapeutic range - Drug metabolites (e.g., N-acetylprocainamide) may need to be measured as well as the parent drug
Drug metabolites (e.g., N-acetylprocainamide) may need to be measured as well as the parent drug
Thin-layer chromatography is particularly useful as a tool in the identification of: - Steroids - Enzymes - Drugs - Hormones
Drugs
Which of the following would likely be positive on a patient with tertiary syphilis? - VDRL - FTA-ABS - RPR - Reagin screen test (RST)
FTA-ABS
The rapid agglutination test for the detection of rheumatoid factors utilizes: - Fc portion of the IgG molecule - Fab portion of the IgG molecule - Whole IgM molecules - Fc portion of the IgM molecule
Fc portion of the IgG molecule
The lecithin to sphingomyelin ratio (L/S) is used to assess: - Fetal neurological development - Fetal lung maturity - Fetal viability - Fetal liver development
Fetal lung maturity
After experiencing extreme fatigue and polyuria, a patient's basic metabolic panel is analyzed in the laboratory. The result of the glucose is too high for the instrument to read. The laboratorian performs a dilution using 0.25 mL of patient sample to 750 uL of diluent. The result now reads 325 mg/dL. How should the technologist report this patient's glucose result? - 325 mg/dL - 1300 mg/dL - 975 mg/dL - 1625 mg/dL
1300 mg/dL
Determine the anion gap given the following information: Na = 134 mmol/L, Cl = 92 mmol/L, HCO3- = 24 mmol/L - 20 mmol/L - 12 mmol/L - 66 mmol/L - 18 mmol/l
18 mmol/L Anion gap = Na - (Cl + HCO3-)
Which wavelength would be absorbed strongly by a red-colored solution? - 450 nm - 650 nm - 585 nm - 600 nm
450 nm
Which of the following is the appropriate reference range for fasting blood glucose? - 65-99 mg/dL (3.61-5.50 mmol/L) - 60-140 mg/dL (3.33-7.77 mmol/L) - 75-150 mg/dL (4.16-8.32 mmol/L) - 40-100 mg/dL (2.22-5.55 mmol/L)
65-99 mg/dL (3.61-5.50 mmol/L)
Which of the following patients is most at risk for hyperosmolar nonketotic coma? - A 60-year-old type 1 diabetic patient - A 70-year-old type 2 diabetic patient - A 15-year-old type 1 diabetic patient - A 25-year old type 2 diabetic patient
A 70-year-old type 2 diabetic patient
In therapeutic drug monitoring, a person who is classified as an ultrarapid metabolizer (UM) would need _____________ of a drug metabolized by that enzyme. - A lower dose - A higher dose - The standard dose - There is no such thing as an ultrarapid metabolizer
A higher dose
Which of the following is an example of a specimen which requires a chain-of-custody procedure to be followed? - A throat swab collected in a outpatient clinic - A urine drug screen for pre-employment - A sputum culture on a emergency room patient suspected of pneumonia - A urine culture on a pediatric patient with a urinary tract infection (UTI)
A urine drug screen for pre-employment
Ammonia is BEST characterized as being: - A waste product of amino acid and protein metabolism - Obtained from hydrolysis of urea in the kidney - Obtained from ingested carbohydrates - An odor common to urine
A waste product of amino acid and protein metabolism
Ammonia is BEST characterized as being: - A waste product of amino acid protein metabolism - Obtained from hydrolysis of urea in the kidney - Obtained from ingested carbohydrates - An odor common to urine
A waste product of amino acid protein metabolism
Which of the following analytes would be increased due to delay in centrifugation? - Bicarbonate - AST - Glucose - Ionized calcium
AST
Which of the following would be considered a normal cerebrospinal fluid glucose level if the serum glucose is 70 mg/dL? - About 100 mg/dL - About 45 mg/dL - About 60 mg/dL - About 70 mg/dL
About 45 mg/dL
In absorption spectrophotometry: - Percent transmittance is directly proportional to the light path length - Absorbance is directly proportional to transmittance - Percent transmittance is directly proportional to concentration - Absorbance is directly proportional to concentration
Absorbance is directly proportional to concentration
Ion selective electrodes, for pH determinations, are called selective rather than specific because they actually measure the: - Activity of one ion only - Concentration of one ion - Activity of one ion much more than other ions present - Concentration and activity of one ion only
Activity of one ion much more than other ions present
What is the term used to describe cardiac tissue death due to lack of oxygen caused by obstruction of circulation? - Acute myocardial infarction (AMI) - Angina - Congestive heart failure (CHF) - Myocardial ischemia
Acute myocardial infarction (AMI)
Which analyze should be increased in the presence of pancreatitis? - Uric acid - Aldolase - Amylase - Troponin
Amylase
Of the following enzymes, which are used for the diagnosis of acute pancreatitis? - 5'-nucleotidase (5'N) and gamma-glutamyl transferase (GGT) - Aspartate aminotransferase (AST) and alanine aminotransferanse (ALT) - AST and lactate dehydrogenase (LDH) - Amylase (AMS) and lipase (LIP)
Amylase (AMS) and lipase (LIP)
Which of the following is not a requirement for a quality control (QC) material? - Analyze concentration must be independent of the method of assay - The matrix is similar to the specimens being tested - The concentration of analytes reflects the clinical range - Long-term stability
Analyze concentration must be independent of the method of assay
What is the term used to describe chest pain caused by inadequate supply of oxygen to heart myocardium? - Acute myocardial infarction (AMI) - Angina - Congestive heart failure (CHF) - Myocardial ischemia
Angina
Which of the following is correct regarding serum urea? - Levels are independent of diet - BUN is elevated in prerenal as well as renal failure - Urea is not reabsorbed by the renal tubules - High BUN levels can result for necrotic liver disease
BUN is elevated in prerenal as well as renal failure
Cyclosproine and tacrolimus (both immunosuppressive drugs) have multiple therapeutic ranges, why? - There is no therapeutic range established for either - Because of the slow uptake of the medications by tissues - Because both drugs have ranges dependent on the organ transplanted and the time after transplantation - Because of the short half-lives of the drugs
Because both drugs have ranges dependent on the organ transplanted and the time after transplantation
Select the mechanism that is responsible for metabolic acidosis: - Excessive retention of dissolved CO2 - Hyperaldosteronism - Bicarbonate deficiency - Accumulation of volatile acids
Bicarbonate deficiency
Fecal urobilinogen level may be markedly decreased because of: - Hemolysis - Decreased intestinal reabsorption of urobilinogen - Increased serum bilirubin - Biliary obstruction
Biliary obstruction
Which of the following happens when iron is in the oxidized (Fe3+) state? - Reaction with chromogens in colorimetric assays - Absorption by intestinal epithelium - Binding to transferrin and incorporation into ferritin - Incorporation into protoporphyrin IX to form functional heme
Binding to transferrin and incorporation into ferritin
What is the elution order of volatiles in gas chromatography based on? - Carbon content - Molecular size - Polarity - Boiling point
Boiling point
Kernicterus is an abnormal accumulation of bilirubin in the: - Heart tissue - Brain tissue - Liver tissue - Kidney tissue
Brain tissue
Which of the following tumor markers is used to measure the recurrence of breast cancer? - CA-15-3 - Estrogen receptor (ER) - Retinoblastoma gene - Cathespin-D
CA-15-3
Following a myocardial infarction which of the following enzymes will be the first to become elevated? - CK - LDH - GGT - ALT
CK
Which of the following will peak first after an acute myocardial infarction? - LDH - ALT - CK - AST
CK
All of the following statements concerning CK-MB (CK-2) are true EXCEPT: - Greater than 5% or 10 IU/L followed by an LDH-1; LDH-2 flip is specific evidence of myocardial infarction (MD) - CK-MB levels can be normal with an elevated total CK - CK-MB and troponin levels can be elevated after an AMI - CK-MB levels are normal in cardiac ischemia
CK-MB levels are normal in cardiac ischemia
Specimen hemolysis would have the least effect on: - Calcium - Potassium - Phosphorus - Magnesium
Calcium
All of the following are therapeutic drugs used to treat cardiac disease, EXCEPT? - Carbamazepine - Digoxin - Procainamide - Quinidine
Carbamazepine
A 14-year-old male was taken to ER in a coma by his school nurse. He had lost 15 pounds in 3 months. His teacher said he was always thirsty and that was he spent a lot of time running between the water fountain and the bathroom. Considering the patient's results and symptoms, what could be the cause for the osmolality result, and increased thirst? Results: pH = 7.11 (7.35-7.45), pCO2 = 20 mmHg (35-45), Glucose = 1050 mg/dL (60-110), Serum osmolality = 385 mOsm/Kg (275-295), Urine ketone strongly positive (negative), Urine glucose strongly positive (negative) - Because the patient is in a coma, it has been a prolonged period since he has eaten or drank water - The increased glucose level causes a more concentrated extracellular solution, stimulating the thirst center of the hypothalamus - The increased glucose level causes water to go inside the cell to equilibrate with the extracellular fluid - None of the above
The increased glucose level causes a more concentrated extracellular solution, stimulating the thirst center of the hypothalamus
Proteins in a buffer that sets the pH at 8.6 will become ____________ charged and migrate to the ___________. - Negatively; anode - Negatively; cathode - Positively; anode - Positively; cathode
Negatively; anode
Of the following, which is the most common cause of Cushing's syndrome? - Ectopic adrenocorticotropic hormone (ACTH) production by tumors - Adrenal hyperplasia - Overuse of corticosteroids - Pituitary adenoma
Overuse of corticosteroids
Which of the following accurately states the effect on a normal arterial blood sample after exposure to room air? - PO2 decreased, PCO2 decreased, pH decreased - PO2 increased, PCO2 decreased, pH increased - PO2 decreased, PCO2 increased, pH decreased - PO2 increased, PCO2 decreased, pH decreased
PO2 increased, PCO2 decreased, pH increased
The study of drug disposition in the body - how and when drugs enter the circulation, how long they stay there, and how they are eliminated is called? - Drug half-life - Therapeutic window - Pharmacokinetics - Pharmacogenomics (pharmacogenetics)
Pharmacokinetics
Which enzyme deficiency causes phenylketonuria (PKU)? - p-Hydroxyphenylpyruvic acid oxidase - Homogentisic acid oxidase - Phenylalanine hydroxylase - Tyrosine transaminase
Phenylalanine hydroxylase
Follicle stimulating hormone (FSH) is produced by: - Adrenal cortex - Adrenal medulla - Pituitary - Thyroid
Pituitary
Which of the following electrolytes is most likely to be spuriously elevated in a hemolyzed specimen? - Sodium - Potassium - Chloride - BUN
Potassium
Which of the following contributes to specific gravity but does not contribute to osmolality? - Protein - NaCl - Urea - Glucose
Protein
Glycated (glycosylated) hemoglobin: - Has a sugar attached to the C-terminal end of the beta chain - Will be abnormal within 4 days following an episode of hyperglycemia - Reflects the extent of glucose regulation in the 8-12 week interval prior to sampling - Requires a fasting blood specimen for analysis
Reflects the extent of glucose regulation in the 8-12 week interval prior to sampling
Which of the following is characteristic of type 1 diabetes mellitus? - Is the most common form of diabetes mellitus - Requires insulin replacement to prevent ketosis - Requires an oral glucose tolerance test for diagnosis - Usually occurs after age 40
Requires insulin replacement to prevent ketosis
What would be the result of a prolonged color reaction phase in one tube or well of an enzyme-linked immunosorbent assay (ELISA) test? - Result would be unaffected - Result would be falsely decreased - Not possible to determine - Result would be falsely increased
Result would be falsely increased
The Jaffe method for creatinine measurement uses which of the following reagent(s)? - Saturated picric acid and NaOH - Alkaline copper II sulfate - Sodium nitroprusside and phenol - Phosphotungstic acid
Saturated picric acid and NaOH
What can be used to detect stray light in a spectrophotometer? - Mercury vapor lamp - Sharp cutoff filter - Potassium dichromate solution - Holmium oxide glass
Sharp cutoff filter
The measurement of 17-ketosteroids (17-KSs) in urine is performed to assess PRIMARILY which organ(s)? - Testes - Adrenal cortex - Testes and adrenal cortex - Anterior pituitary
Testes and adrenal cortex
The pharmacogenetic profiling reveals a mutation in a CYP450 enzyme that causes increased enzyme activity. Which of the statements below is incorrect? - There are variations in the enzymes as a result of genetic polymorphism - It would require that the patient with this mutation is given greater than the standard dose of a drug if it is metabolized by this enzyme - The profiling can be used to predict drug-drug interactions - The CYP450 variants have no influence on drug metabolism
The CYP450 variants have no influence on drug metabolism
The pharmacogenetics profiling reveals a mutation in a CYP450 enzyme that causes increased enzyme activity. Which of the statements below is incorrect? - There are variations in the enzymes as a result of genetic polymorphism - It would require that the patient with this mutation is given greater than the standard dose of a drug if it is metabolized by this enzyme - The profiling can be used to predict drug-drug interactions - The CYP450 variants have no influence on drug metabolism
The CYP450 variants have no influence on drug metabolism
Urea is produced from: - The catabolism of proteins and amino acids - Oxidation of purines - The breakdown of complex carbohydrates - Oxidation of pyrimidines
The catabolism of proteins and amino acids
What is the primary mechanism of compensation for metabolic acidosis? - Hyperventilation - Release of epinephrine - Aldosterone release - Bicarbonate excretion
Hyperventilation
Which of the following is the primary mechanism causing respiratory alkalosis? - Deficient alveolar diffusion - Hyperventilation - Deficient pulmonary perfusion - Parasympathetic inhibition
Hyperventilation
Which of the following would most likely be true of patients with B cell deficiencies? - Increased complement levels - Decreased phagocytosis - Increased bacterial infections - Decreased complement levels
Increased bacterial infections
Which of the following is not a function of immunoglobulins? - Combining with complement to destroy cellular antigens - Interacting with cytotoxic T cells to lyse viruses - Facilitating phagocytosis through opsonization - Neutralizing toxic substances
Interacting with cytotoxic T cells to lyse viruses
What is the function of LD in the body? - Interconversion of lactate to glucose - Non-reversible conversion of pyruvate to lactate - Interconversion of lactate and pyruvate - Conversion of glucose to lactate
Interconversion of lactate and pyruvate
Which of the following is necessary for the absorption of Vitamin B12: - Intrinsic factor - Folic acid - Gastrin - Insulin
Intrinsic factor
Which of the following is true regarding glucose values in cerebrospinal fluid (CSF)? - In some clinical conditions, the CSF glucose level can be higher than the plasma glucose level - CSF glucose levels are normally the same as plasma glucose levels - Hyperglycorrhachia is caused by dehydration - Levels below 40 mg/dL occur in septic meningitis, cancer, and multiple sclerosis
Levels below 40 mg/dL occur in septic meningitis, cancer, and multiple sclerosis
Which of the following is correct about glucose in cerebrospinal fluid? - Levels below 40 mg/dL occur in septic meningitis, multiple sclerosis, and cancer - Hyperglycorrhachia is caused by dehydration - In some clinical conditions, the CSF glucose level can be higher than the plasma glucose level - The CSF glucose level is normally the same as the plasma glucose level
Levels below 40 mg/dL occur in septic meningitis, multiple sclerosis, and cancer
Select the plot that is best for detecting all types of quality control errors: - Tonk-Youden - Levy-Jennings - Cusum - Linear regression
Levy-Jennings
When measuring enzyme activity, if the instrument is operating 5C lower than the temperature prescribed for the method, how will the results be affected? - Lower than actual - Higher than actual - Varied, showing no particular pattern - No effect
Lower than actual
What are the two polypeptide chains that comprise the LD molecule? - M and B - M and B - H and B - M and H
M and H
Isoenzymes of CK include all of the following EXCEPT: - MB - MM - MBM - BB
MBM
Consider the following blood gas results: pH = 7.55, PCO2 = 55 mmHg, HCO3 = 40 mmol/L These results indicate: - Metabolic acidosis - Metabolic alkalosis - Respiratory acidosis - Respiratory alkalosis
Metabolic alkalosis
All of the following statements are true regarding the hepatic system and drug metabolism, EXCEPT? - Changes in hepatic status will affect the concentration of circulating drugs eliminated - Hepatic disease states characterized by a loss of functional tissue may result in slower rates of clearance - Hepatic disease states characterized by a loss of functional tissue may result in a longer drug half-life - Metabolism of acetaminophen by the MFO system is altered by alcohol and makes it less toxic
Metabolism of acetaminophen by the MFO system is altered by alcohol and makes it less toxic
A patient has an antibody test for HIV performed and the result comes back negative. A week later, the physician has a PCR test for HIV performed on the same patient, which comes back positive. Which of the following provides the best explanation for the results? - The tests were not performed properly - The patient is in the "window phase" prior to antibody production - The PCR result is a false positive - The patient's clinical symptoms were misinterpreted
The patient is in the "window phase" prior to antibody production
If a disease or disorder causes serum binding proteins (such as albumin) to decrease, what may occur if the dose of a highly protein-bound drug with a narrow therapeutic window is not adjusted? - The patient may not realize a therapeutic benefit (low free drug fraction) - The patient may experience toxic effects (high free drug fraction) - The serum level of the drug will most likely remain in the therapeutic range - Not enough information is provided to determine the effect of the drug on the patient
The patient may experience toxic effects (high free drug fraction)
What conclusion can be made if a person has a cardiovascular risk marker that is abnormal? - The person will have a cardiovascular event within the next 12-24 months - The person has an increased probability of developing cardiovascular disease - The person has a decreased probability of developing cardiovascular disease - With only one abnormal marker, the person is not at risk of developing cardiovascular disease
The person has an increased probability of developing cardiovascular disease
Which of the following is a characteristic of obstructive jaundice? - The ratio of direct to total bilirubin is greater than 1:2 - Urinary urobilinogen is increased - Conjugated bilirubin is elevated, but unconjugated bilirubin is normal - Urinary bilirubin is normal
The ratio of direct to total bilirubin is greater than 1:2
A serum specimen for potassium testing is collected in a red top tube without a gel separator barrier. If testing is delayed by a few hours, how should the specimen be handled? - Discard the specimen and recollect right before testing is available again - Discard the specimen and recollect in a gel separator tube - The specimen should be centrifuged as soon as it clotted and serum should be transferred to another tube - There is not special handling procedure for this specimen
The specimen should be centrifuged as soon as it clotted and serum should be transferred to another tube
How is the majority of urobilinogen that is produced daily removed from the body? - Through urine excretion - Through sweat - Through saliva - Through fecal excretion
Through fecal excretion
A patient who does not fast prior to having a lipid profile performed would have a falsely elevated: - HDL - Cholesterol - LDL - Triglyceride
Triglyceride
Select the biochemical process that is promoted by insulin: - Glycogenolysis - Uptake of glucose by cells - Gluconeogensis - Lipolysis
Uptake of glucose by cells
Confirmation testing on a sample for drugs of abuse would utilize which of the following methods? - Enzyme-multiplied immunoassay technique (EMIT) - High-performance liquid chromatography (HPLC) - Thin-layer chromatography (TLC) - Gas chromatography with mass spectroscopy (GC-MS)
Gas chromatography with mass spectroscopy (GC-MS)
All of the following hormones are produced primarily in the pancreatic islets EXCEPT which one? - Gastrin - Glucagon - Insulin - Pancreatic polypeptide
Gastrin
Hydrogen ion concentration (pH) in blood is usually determined by means of which of the following electrodes? - Silver - Glass - Platinum - Gold
Glass
A 47-year-old female's clinical symptoms include hair loss, fatigue, and heat intolerance. Her lab results showed abnormally low total T4 and free T4, along with a significantly elevated TSH. This is indicative of: - An adenoma of the thyroid - Graves disease - Thyrotoxicosis - Primary hypothyroidism
Graves disease
Which of these blood levels will decrease during intravascular hemolysis? - Serum (plasma) LDH - Serum (plasma) bilirubin - Reticulocytes - Haptoglobin
Haptoglobin
A critically ill 86-year-old female was admitted to the intensive care unit (ICU) after arriving at the emergency department with symptoms that included shortness of breath and fever. Her temperature was 39C and pulse rate 110/minute. A white blood count (WBC) was ordered and was elevated at 15.0 x 10^9/L. The differential showed an increase in segmented and immature neutrophils. Other testing was ordered after admission to ICU, including a procalcitonin (PCT). The result was 2.15 ng/mL (reference value for normal at the 95th percentile is <0.05 ng/mL). Given the clinical assessment and laboratory test results, what may the increased procalcitonin indicate? - Low risk of severe sepsis/septic shock - High risk of severe sepsis/septic shock - Systemic inflammation, not related to infection - No risk of severe sepsis/septic shock
High risk of severe sepsis/septic shock
Secondary immune response results in high titers of which of the following? - IgM - IgA - IgE - IgG
IgG
Which is the first immunoglobulin to appear in primary immune response to an antigen? - IgG - IgE - IgM - IgA
IgM