CHEM 2 Final Exam
The urinary metabolite of cortisol and adrenal androgens is: 17-ketosteroid. 11-desoxycortisol. 17-hydroxyprogesterone. renin.
17-ketosteroid.
Deficiency of which of the following enzymes commonly lead to congenital adrenal hyperplasia (CAH)? 17-Ketosteroidase 21-Alpha-hydroxylase 11-Beta-hydroxylase
21-Alpha-hydroxylase
You want to quantify the amount of barbituate in patient samples. You take 0.5 mL of whole blood and add 30 picomoles of the internal standard (d6+ barbituate) to the tube. After mixing the tube well, you take 20 uL from the tube and analyze the sample by mass spec. You get the following results: d6+ barbituate = 2000 ion counts, patient barbituate = 8000 ion counts. What is the actual blood concentration of barbituate in the patient sample in pmol/mL? 60 120 180 240
240
You want to analyze barbituate in patient samples. You take 0.5 mL of whole blood and add 30 picomoles of the internal standard (d6+ barbituate) to the tube. After mixing the tube well, you take 20 uL from the tube and analyze the sample by mass spec. You get the following results: d6+ barbituate = 2000 ion counts, patient barbituate = 8000 ion counts. If barbituate has an m/z ratio of 286 in MS, what is the m/z ratio of the internal standard that was used? 274 280 286 292
292
Which of the following set of wavelengths is most representative of the visible region?
350-750 nm
As a screening test for Cushing's syndrome, the physician wishes to see whether a patient exhibits normal diurnal rhythm of his cortisol secretion. At what time should the specimens be drawn for plasma cortisol determination? (Assume a daytime work schedule for the patient.) Noon, midnight 6 AM, noon 8 AM, 8 PM Noon, 6 PM 8 AM, 2 PM
8 AM, 8 PM
For the past 3 weeks, serum estriol levels in a pregnant woman have been steadily increasing. This is consistent with: A normal pregnancy Fetal death Hemolytic disease of the newborn Congenital cytomegalovirus infection
A normal pregnancy
A common internal standard used in mass spec methods is: A standard labeled with hydrogen A standard labeled with deuterium A standard labeled with tritium A standard labeled with nitrogen
A standard labeled with deuterium
The oncofetal antigen associated with liver cancer is: CEA hCG AFP PSA
AFP
Unconjugated bilirubin circulated in the bloodstream is bound to: Glucuronic acid Transferrin Sulfanilic acid Albumin Alpha-1 globulin
Albumin
Which of the following statements concerning amenorrhea is (are) correct? All of the answers are correct. Primary amenorrhea is defined as the absence of menstrual bleeding in women who have never menstruated. Hirsutism is a typical side effect of amenorrhea caused by androgen excess. One cause of primary amenorrhea is Turner syndrome, in which there is no estrogen production by the ovaries.
All of the answers are correct.
Fluorescence probes.... a. are highly fluorescent reagents that are designed to bind strongly and specifically to certain targets, b. are the basis of many very sensitive assays developed biological molecules of interest c. enable the use of fluorescence for the detection of molecules that are not fluorescent d. all of the choices are correct
All of the choices are correct
High performance liquid chromatography utilizes all but the following components: a.A mobile phase pump b. A stationary phase column c. An injector to volatilize sample d. A eluate component detector e. A chromatographic recorder
An injector to volatilize sample
Which of the following genetic markers is associated with breast cancer? Rb CA-125 WT1 BrCA-1/2
BRCA-1/2
Tumor-associated antigens composed of high-molecular-weight mucin-like glycoproteins include: BRCA-1 and -2 CA 125 and CA 19-9 p53 and Rb PSA and AFP
CA 125 and CA 19-9
In thin layer chromatography, the solvent migrates up the sorbent (ex. alumina, silica gel, cellulose. by which action: a. Inert carrier gas such as argon b. Capillary action c. Suction d. Electromagnetic field e. Force applied by a battery
Capillary action
The parent substance of all steroid hormones is: Cholesterol Catecholamines Progesterone Amino acid Cortisol
Cholesterol
A genetic disorder causing a deficiency of certain enzymes in the synthetic pathways leading to cortisol and aldosterone production is referred to as: Congenital adrenal hyperplasia Conn's syndrome Addison's disease Cushing's syndrome
Congenital adrenal hyperplasia
In HPLC, analyte detectors can consist of fluorometers, photometers, and electrochemical detectors. An electrochemical detector measures an electroactive analyte by: Correct monitoring the current that is generated by oxidation or reduction reaction under a constant potential voltage and that is proportional to the concentration of analyte. measuring an electrical potential difference between two electrodes. measuring the radiant energy given off when the chemical bonds of an element are dissociated and the element is placed in a ground or atomic state. measuring both an alteration in enzyme level and a redox reaction at a potentiometric ion-specific electrode.
Correct monitoring the current that is generated by oxidation or reduction reaction under a constant potential voltage and that is proportional to the concentration of analyte.
Pituitary secretion of adrenocorticotropic hormone (ACTH) is inhibited by elevated levels of: Cortisol Estradiol-17b Progesterone Aldosterone Epinephrine
Cortisol
You operate a laboratory that receives many serum specimens from the Billy Rubin Memorial Liver Clinic next door. The patients who go to this clinic have serious acute and chronic liver diseases. Would you expect to see increased or decreased plasma albumin from the liver patients who go to this clinic? Increased Decreased
Decreased
Chronic fetal metabolic distress is demonstrated by: Decreased urinary estriol excretion and decreased maternal serum estriol Increased urinary estriol excretion and increased maternal serum estriol Decreased estrogen in maternal plasma and increased estriol in amniotic fluid Increased estradiol in maternal plasma with a corresponding increase of estriol in amniotic fluid
Decreased urinary estriol excretion and decreased maternal serum estriol
Select the true statement about fluorescence spectroscopy of molecules in the UV visible region a. Emission usually occurs at energies that are greater than the energies of excitation b. Emission usually occurs at energies that are less than the energies of excitation c. Emission usually occurs at energies that are equal to the energies of excitation. d. All of the choices are correct.
Emission usually occurs at energies that are less than the energies of the excitation
Which one of the following would be a limitation in a nephelometric measurement that might produce faulty values? Excess antigen in the antigen/antibody reaction Too much fluorophore in the analyte/fluorescing compound mixture Incorrect filter used to isolate a specific wavelength Absorption by a closely related atomic species
Excess antigen in the antigen/antibody reaction
True or False Wavelengths that occur in the blue violet region have low energy compared to wavelengths composing the orange red region
False
What soluble iron-protein complex is the form in which iron is stored in tissues? Transferrin Ferritin Hemosiderin Hemoglobin
Ferritin
The formation of estriol in a pregnant woman is dependent on: Fetal and placental function Maternal ovarian function Maternal liver function Fetal adrenal function
Fetal and placental function
When selecting a photometric technique that is more sensitive to a low concentration of analyte, a laboratory director compares absorbance measuring devices against those that measure fluorescence intensity. Which technique is considered more sensitive in its measurements and why? Absorbance measurements are more sensitive because of the ability of the monochromator to isolate very specific parts of the spectrum. Fluorescence intensity measurements are more sensitive because the fluorophores used are very specific to the analytes they bind to and will bind to small analytes easily. Fluorescence intensity measurements are more sensitive because of the use of intense light sources, signal filtering, and sensitive light emission photometers. Absorbance measurements are more sensitive because the flame can break down complex compounds into elements that are specifically measured.
Fluorescence intensity measurements are more sensitive because of the use of intense light sources, signal filtering, and sensitive light emission photometers.
In the clinical toxicology lab, it is common to use _____ to measure drug of abuse a. Gas chromatography mass spectrometer b. Thin-layer chromatography c. Atomic absorption d. Electrophoresis
Gas chromatography mass spectrometer
A patient presents with yellowish skin and eyes, fatigue, and mild motor system dysfunction. Upon assessment in the laboratory, the total bilirubin concentration was shown to be 3.0 mg/dL (normal 0.2-1.0 mg/dL) with negative urinary bilirubin. Liver function tests are normal. The most likely diagnosis in this case would be: Gilbert syndrome. Lucey-Driscoll syndrome. hemolytic anemia. Crigler-Najjar syndrome type II.
Gilbert syndrome.
An example of ectopic hormone production would be: Prolactin production by pituitary tumors Growth hormone production by lung tumors Cortisol production by adrenal tumors Growth hormone production by pituitary tumors Corticotropin releasing hormone from hypothalamus
Growth hormone production by lung tumors
Secretion of hormones by the anterior pituitary is controlled by circulating levels of hormones from the target gland and hormones secreted by the: Hypothalamus Pineal gland Adenohypophysis Posterior lobe of the pituitary gland Intermediate lobe of the pituitary gland
Hypothalamus
The definitive diagnosis of primary adrenal insufficiency requires demonstration of: Decreased urinary 17-keto- and 17-hydroxysteroids Increased urinary cortisol excretion after metyrapone Impaired response to ACTH stimulation Decreased cortisol production
Impaired response to ACTH stimulation
Which one of the following statements concerning nephelometry is correct? Nephelometry is the measure of the concentration of particles by measuring the amount of incident light blocked by the particles. In a nephelometric measurement, light blocked by solutes in the solution at 180° from the incident light is measured by a photodetector. The decrease in the intensity of scattered light is directly proportional to the number of particles in the solution, and the measurement of this decrease is called nephelometry. In a nephelometric procedure, the measurement of scattered light that is not in the direct path of the transmitted light is made at right angles to the incident light.
In a nephelometric procedure, the measurement of scattered light that is not in the direct path of the transmitted light is made at right angles to the incident light.
Which one of the following statements concerning androstenedione is incorrect? The precursor molecule in the formation of androstenedione is dihydroepiandrostenedione (DHEA). In adrenal carcinoma, cortisol is greatly elevated, but androstenedione is greatly decreased. Androstenedione metabolites are measured as 17-ketosteroids. 11β-Hydroxylase deficiency leads to elevated plasma androstenedione.
In adrenal carcinoma, cortisol is greatly elevated, but androstenedione is greatly decreased.
Regarding the individual using progesterone-based oral contraceptives, would the transferrin saturation be increased, decreased, or not affected? Increased Decreased Not affected
Increased
Energy of frequency of light wave varies ____ with the wavelength inversely or directly
Inversely
In regard to mass spectrometry, what is a molecular ion? It is a component of a compound in solution. It is the sum of all ions produced displayed as a function of time. It is the unfragmented ion of the original molecule being studied. It is the ion with the highest abundance in the mass spectrum of a compound.
It is the unfragmented ion of the original molecule being studied.
The main advantage of fluorescence over UV V is spectroscopy is _____ a.Its sensitivity b. Its compatibility with separation techniques c. Its compatibility with most analytes d. None of the above
Its sensitivity
The placenta secretes numerous hormones, both protein and steroid. Which of the following hormones is not secreted by the placenta? Correct! Leutinizing hormone Progesterone Estrogen Human Chorionic gonadotropin
Leutinizing hormone
Serum bilirubin is unstable because of: Digestion by proteolytic enzymes Precipitates on standing Light sensitivity Precipitation due to acid pH
Light sensitivity
A patient presents with Addison's disease. Serum sodium and potassium analyses are done. The results would reveal: Normal sodium, low potassium levels Low sodium, high potassium levels Low sodium, low potassium levels High sodium, low potassium levels
Low sodium, high potassium levels
Clinical assays for tumor markers are most important for: Monitoring the course of a known cancer Screening for the presence of cancer Identifying patients at risk for cancer Confirming the absence of disease
Monitoring the course of a known cancer
AFP and CEA are examples of which type of tumor marker? Carcinoma-associated antigen Oncofetal antigen Enzyme Hormone
Oncofetal antigen
Which of the following statements is TRUE? Partition chromatography is most appropriate to identifying analytes that may be distributed between two liquid phases. Steric exclusion chromatography is best suited for separating analytes based on their solubility in the mobile solvent. In liquid-solid chromatography, the stationary phase separates analytes based on size, shape, and polarity. Ion-exchange chromatography has a resin phase that is soluble to water and separation of the mixture is based on magnitude and charge of ionic species. The partition coefficient is measured and compared to standards in thin-layer chromatography.
Partition chromatography is most appropriate to identifying analytes that may be distributed between two liquid phases.
When elevated amounts of bilirubin are presented to the liver with elevated serum unconjugated bilirubin, what type of jaundice occurs? Prehepatic Biliary Posthepatic Hepatic
Prehepatic
The most specific tumor marker for prostatic cancer is: Prostate specific antigen Human chorionic gonadotropin Alpha-fetoprotein Prostatic acid phosphatase
Prostate specific antigen
An internal standard can be used in some mass spec assays in order to: Provide a way to determine the concentration of the analyte of interest Determine the identity of the analyte Provide a way to determine the callibration of the instrument None of the choices are correct.
Provide a way to determine the concentration of the analyte of interest
Production of bilirubin occurs in the __________, and conjugation of bilirubin to glucuronide occurs in the _____________. Liver; RES Liver; intestine RES; liver RES; intestine
RES; liver
A patient is suspected of having Addison's disease. His laboratory tests show low serum sodium and chloride, elevated serum potassium, and elevated urine sodium and chloride levels. The aldosterone cortisol levels are decreased. To make a definitive diagnosis, the physician orders an ACTH stimulation test, and the cortisol level is measured again. If the patient has Addison's disease, the cortisol level would ________. If the patient has hypopituitarism, the levels would _______. Increase; remain the same Increase; decrease Decrease; increase Remain the same; increase Decrease; decrease
Remain the same; increase
In the isolation of nucleic acids from blood samples, a step is typically performed to separate large molecules, such as proteins and nucleic acids, from smaller molecules such as salts. Which type of separation mechanism would best be suited for this task? Ion exchange Affinity Partition Size-exclusion
Size-exclusion
The most widely used method for bilirubin analysis uses two reagents, ____________ and ___________, in the diazo reaction. Glucuronic acid; sodium nitrate Sulfanilic acid; sodium nitrate Sulfanilic acid; sodium nitrite Glucuronic acid; sodium nitrite
Sulfanilic acid; sodium nitrite
Which one of the following statements concerning total iron binding capacity (TIBC) is not correct? TIBC is decreased in chronic inflammatory disorders. Transferrin saturation = (serum iron/TIBC) × 100. TIBC is proportional to the amount of transferrin present. TIBC is decreased in an iron deficiency anemia.
TIBC is decreased in an iron deficiency anemia.
The three levels of dysfunction that may be evaluated in a patient with an endocrine problem are primary, secondary, and tertiary. The possible defective sites that correspond to these primary, secondary, and tertiary levels of dysfunction are, respectively: Hypothalamus, target gland, pituitary Target gland, hypothalamus, pituitary Pituitary, target gland, hypothalamus Pituitary, hypothalamus, target gland Target gland, pituitary, hypothalamus
Target gland, pituitary, hypothalamus
Laboratory analysis of free thyroxine (fT4) in your chemistry laboratory is performed with a conventional fluorometric analyzer, which uses a laser light as the excitation source. You have received a sample from an individual known to have a very elevated fT4 level. For the sample's value to be within linear range of the assay, you dilute the sample by a factor of 10 and proceed with the analysis. Upon reviewing the results, you note that the value of the diluted sample is reported as "none detected." What is the likely reason for this result? Hormones cannot be assayed using fluorometry because they will produce concentration quenching. The dilution of the sample has lowered produced photobleaching by the intense light source and photodecomposition of the analyte. produced a false-negative result. High intensity light emission can lead to pulse pileup in photomultiplier tubes, leading to an underestimation of the true light emission intensity.
The dilution of the sample has lowered produced photobleaching by the intense light source and photodecomposition of the analyte.
The partition coefficient is a. The ratio of the mass to charge ratios in two liquids b. The ratio of the mass to charge ratios in a liquid and a solid c. The ratio of the concentration of one solute to the volume of another solute d.The ratio of the concentration of the solute in the two liquids
The ratio of the concentration of the solute in the two liquids
In a fluorometric measurement, the difference between the maximum wavelength of the excitation light and the maximum wavelength of the emitted fluorescence light is a constant referred to as: Beer law. chemiluminescence. polarization. the Stokes shift.
The stokes shift
True or False High resolution mass spectrometry is capable of identifying molecules of less than 0.0001 dalton mass
True
True or False Matrix assisted laser desorption ionization time of flight is a useful tool in the identification of microbial fingerprints
True
True or false? If the GLC column oven temperature is not higher than that of the column inside of it, the sample inside the column may not remain the gaseous state
True
True or false? In GLC and HPLC methods, increasing the mobile phase flow rate may make it more difficult in the sample to effectively be separated by the stationary phase
True
True or false? The type of GLC detector best used for detecting and measuring the concentration of pesticides in patient samples is electron captures → most sensitive
True
The enzyme that conjugates bilirubin in the hepatocyte is: Microsomal heme oxygenase Biliverdin reductase Glucuronic aminotransferase UDP-glucuronyl transferase Beta-glucuronidase
UDP-glucuronyl transferase
The test for adrenal cortical hyperfunction that has the greatest diagnostic sensitivity is measurement of: Plasma cortisol Urinary free cortisol Urinary 17-hydroxycorticosteroids Plasma corticosterone
Urinary free cortisol
Bilirubin is reduced to __________ in the small intestine. Porphobilinogen Urobilin Biliverdin Urobilinogen
Urobilinogen
Which one of the following is formed by the reduction of unconjugated bilirubin in the intestines, is found in urine, and is further oxidized to form urobilin? Conjugated bilirubin Iron Hemoglobin Urobilinogen
Urobilinogen
Which one of the following improvements could be made to increase the chromatographic (separation) efficiency of a poorly resolved HPLC separation? Using a shorter column Changing the composition of the mobile phase Using smaller particles in the stationary phase Increasing the dead volume
Using smaller particles in the stationary phase
A molecule is said to fluoresce when it absorbs light at one wavelength and emits light of: a lower energy. a shorter wavelength. a higher energy. the same wavelength.
a lower energy
A molecule is said to fluoresce when it absorbs light at one wavelength and emits light of: a lower energy. a shorter wavelength. a higher energy. the same wavelength.
a lower energy
The functional unit of the liver is the: glomerulus. acinus. nephron. cord.
acinus.
What reagent is used in the bilirubin method to shift the color reaction to a wavelength with less interference? Correct Answer Alkaline tartrate Ascorbic acid Active diazo Hydrochloric acid
active diazo
Some analytes must be derivatized to increase their column retention or detectability. Derivatization means: altering the chemical structure of the analyte to an isomeric form to increase detection and specificity. adding fluorescent labels or combining the analyte with chiral reagents or other chemicals to increase detectability. removing dissolved gases in the solvent to produce a clear chromatogram. using multiple detectors to assist in identification.
adding fluorescent labels or combining the analyte with chiral reagents or other chemicals to increase detectability.
The type of separation mechanism for chromatography that involves, as one example, use of immunologic principles is _____ chromatography. ion exchange affinity partition adsorption
affinity
The adrenal cortical hormone that promotes sodium resorption and potassium and hydrogen ion excretion by the renal tubules and thus affects water balance in the body is: calcium. androstenedione. cortisol. aldosterone.
aldosterone.
Which one of the following components is found only in a fluorometer used to make measurements of emitted fluorescent light as opposed to in a spectrophotometer used to make measurements of absorbed/transmitted light? Monochromator Cuvets as sample holders An excitation source Detector
an excitation source
In a mass spectrometer, the ion with the highest abundance in the mass spectrum that is assigned a relative abundance of 100% is referred to as the: base peak. ion trap. ionic chromatogram. time-of-flight ion.
base peak
The properties of an ideal tumor marker include all of the following, except it should: be produced by tumor cells and detectable in body fluids. be specific for a given type of cancer. not be present in healthy people. be able to distinguish between benign and malignant tumors.
be able to distinguish between benign and malignant tumors.
The major substance formed from the breakdown of hemoglobin when senescent red blood cells are phagocytized by the reticuloendothelial system is: myoglobin. urobilinogen. bilirubin. urobilin.
bilirubin.
CEA is most commonly associated with: Myelocytic leukemia Breast cancer Ovarian cancer Colon cancer
colon cancer
Which of the following is NOT commonly used as a tumor marker? Cortisol Alpha-fetoprotein Carcinoembryonic antigen Prostate specific antigen
cortisol
The primary glucocorticoid is: cortisol. epinephrine. glucose. aldosterone.
cortisol.
Typical findings in a woman in menopause include: hirsutism. increased progesterone. decreased serum LH/FSH. decreased estrogen and inhibin.
decreased estrogen and inhibin.
In a certain hemoglobin structural variant, a deletion in the coding gene results in a reduction of the production of the beta globin chain. This will result in: decreased quantity of HbA. an α-thalassemia due to overproduction of alpha-globin chains. hemolysis of red blood cells due to unstable hemoglobin. a sickling disorder due to insoluble hemoglobin.
decreased quantity of HbA.
The most common cause of iron deficiency anemia in children is: hemolytic anemias. megaloblastic anemia. bleeding ulcers. dietary deficiency.
dietary deficiency.
The "spreading" of a white beam of light into a spectrum is called: Diffraction Dispersion Refraction Reflection
dispersion
A toxicology screen is set up using thin layer chromatographic plates. Four positive controls/standards are used with the following distance of migration from application point results: Std A = 8 cm; Std B = 15 cm; Std C = 22. The acetone solvent front moved 35 cm. After processing an unknown sample, a solute had a migration distance of 16 cm. What are the retention factors (Rf) of standards A, B, and C? 8, 15, 22 8, 12, 18 4.4, 2.3, 1.5 0.23, 0.43, 0.63
dk
Derivatisation of a sample in gas chromatography is carried out to reduce polarity of the analytes increase the detector response increase volatility of the analytes all of the choices are correct
dk
Helium is generally preferred as carrier gas over hydrogen in gas chromatography because it is inert it has a lower viscosity it doubles up as a party gas for balloons and funny voices all of the choices are correct
dk
Thin layer chromatography is partition chromatography electrical mobility of ionic species adsorption chromatography none of the above
dk
Which of the following devices produces a "linear spectrum"? Filter Prism Diffraction grating Focusing lens
dk
Which of the following statements is true for a refractive index detector in HPLC? It is more sensitive than a UV detector It can only be used for isocratic elutions It does not respond to many solutes all of the choices are correct
dk
Which two optical techniques are combined operationally in a flow cytometer? Laser-induced fluorometry and light scattering techniques Atomic absorption spectrophotometry and light scattering techniques Spectrophotometry and fluorescence polarization techniques Fluorescence polarization and laser-induced fluorometry
dk
A 21-year-old man with nausea, vomiting, and jaundice has the following laboratory findings: Total serum bilirubin 8.5 mg/dL (normal 0-1.0 mg/dL) Direct serum bilirubin 6.1 mg/dL (normal 0-0.5 mg/dL) Urine urobilinogen Increased Urine bilirubin Positive AST 200 U/L (normal 0-50 U/L) ALP 160 U/L (normal 0-150 U/L) What disease state are these findings consistent with? Chronic liver disease Obstructive jaundice Hemolytic anemia Early hepatitis
early hepatitis
In ionization chamber of a mass spectrometer, vapors are bombarded with fast moving protons electrons neutrons antineutron
electrons
Ion exchange chromatography is based on the electrostatic attraction electrical mobility of ionic species adsorption chromatography partition chromatography
electrostatic attraction
A fluorometric measurement technique used to detect immunologic reactions that measures fluorescence produced by the rotation of small versus large fluorescent-labeled molecules and their relation to analyte concentration in an unknown sample is known as: phosphorimetry. reflectance photometry. nephelometry. fluorescence polarization.
fluorescence polarization
The major risk factor for development of hepatocellular carcinoma is: infection with hepatitis B or C viruses. infection with hepatitis A virus. hepatic encephalopathy. hepatorenal syndrome.
infection with hepatitis B or C viruses.
Inhibin: inhibits release of FSH from the male pituitary gland. promotes synthesis of testosterone by the Sertoli cells. augments release of LH from the male pituitary gland. increases in males with elevated GnRH.
inhibits release of FSH from the male pituitary gland.
You are preparing placental tissue for separation and isolation of a specific enzyme. The enzyme has a negative charge, so you want to use chromatography to perform your task. Which one of the following chromatographic separation mechanisms would be most useful? Ion-exchange Partition Affinity Adsorption
ion exchange
Renin is synthesized in the _____ and stimulates the production of angiotensin I, which eventually leads to _____. adrenal gland; an increase in blood pressure and volume kidney; stimulation of aldosterone production adrenal gland; stimulation of cortisol production kidney; lowering of the blood pressure and volume
kidney; stimulation of aldosterone production
In ion exchange chromatography, solute mixtures are separated by virtue of the: a. Magnitude and charge of ionic species b. Partition coefficient between the two liquids c. Steric exclusion based on pore sizes of the column d. Hydrophilic beads of cross-linked dextran
magnitude and charge of ionic species
Mass spectrometry identifies analytes based on
mass to charge ratio
The soft ionization technique that uses a UV-absorbing compound upon which the analyte of interest is placed and eventually vaporized into a plume of ions directed into the mass analyzer is: atmospheric pressure photoionization. electrospray ionization. matrix-assisted laser desorption ionization. inductively coupled plasma ionization.
matrix- assisted coupled plasma ionization
The component used to isolate a wavelength in a spectrophotometer is called a:
monochromator
In measurement of testosterone in blood: assessment of serum 17-ketosteroids is included. morning specimens are preferred because of the diurnal release of testosterone. specimens must be collected in EDTA anticoagulant. 5-androstenediol derivatives are actually measured.
morning specimens are preferred because of the diurnal release of testosterone.
Which one of the following optical techniques is not considered an emission technique? Phosphorimetry Nephelometry Luminometry Fluorometry
nephelometry
In reverse phase chromatography, the stationary phase is made non-polar polar either non-polar or polar none of these
non polar
Activated forms of normal cellular genes are termed: oncogenes. proto-oncogenes. oncofetal antigens. pre-oncogenes.
oncogenes.
Which one of the following optical techniques is not considered an emission technique? Phosphorimetry Nephelometry Luminometry Fluorometry
phosphorimetry
One of the mutations that is found most frequently in cancers and can ultimately lead to colon cancer involves a: frameshift mutation in the N-ras proto-oncogene. large deletion in the N-ras proto-oncogene. point mutation in the K-ras proto-oncogene. translocation of the K-ras proto-oncogene to chromosome 14.
point mutation in the K-ras proto-oncogene.
You have isolated unknown iron containing proteins, including ferritin and myoglobin as impurities from a patient with a novel form of hemoglobinopathy. In the final stage of purification, you decided to use size exclusion chromatography. The expected results would be............. only cationic proteins will be separated. only anionic proteins will be separated. proteins will be separated based on their charge. proteins will be separated based on their relative pI. proteins will be separated based on their relative sizes.
proteins will be separated based on their relative sizes.
Because of the ability to identify and quantify proteins in a complex mixture, mass spectrometry combined with separation methods is an excellent analytical tool used specifically in the field of: genomic research. inborn errors of metabolism. trace metal analysis. proteomics.
proteomics.
Bilirubin is considered to be the breakdown product of: cholesterol. urobilinogen. glucose and maltose. protoporphyrin IX.
protoporphyrin IX.
An isocratic elution in HPLC is one in which the composition of the solvent remains constant changes continuously changes in a series of steps all of the choices are correct
remains constant
An example of a clinical application of an HPLC coupled to a tandem mass spectrometer would be: determining the presence of trace elements in blood. screening and confirming the presence of inborn errors of metabolism. identifying specific protein. quantifying drugs of abuse.
screening and confirming the presence of inborn errors of metabolism.
A type of detector used in GC that is universal in its detection of compounds but has low sensitivity compared with other detectors is a(n) _____ detector. flame ionization thermal conductance electron capture photoionization
thermal conductance
Elevation in serum calcitonin is associated with cancer of the: Colon Ovary Thyroid Stomach
thyroid
Bilirubin that is attached to albumin is called: conjugated bilirubin. urobilinogen. jaundice. unconjugated bilirubin.
unconjugated bilirubin.
In mass spectrometer M/Z is plotted on a. x axis b. y axis c. z axis d. both a and b
x axis
The major site of aldosterone synthesis is the _____ of the adrenal gland. medulla zona glomerulosa zona reticularis zona fasciculata
zona glomerulosa
