Clinical Chemistry I ASCP Review - 467 / Clinical Chemistry I ASCP review (youlazy) Questions & Answers

Clinical Chemistry I ASCP Review - 467 / Clinical Chemistry I ASCP review (youlazy) Questions & Answers Which of the following lamps provides a continuous spectrum of radiant energy in the visible, near IR, and near UV regions of the spectrum? A. Tungsten-filament B. Hydrogen C. Deuterium D. Mercury vapor - CORRECT ANSWER-A most common light source for photometry in the visible region. continuous spectrum (360-800 nm). near IR and UV. Hydrogen and Deuterium (200-375 nm) Mercury vapor- not a continuous spectrum, emitting radiation at specific wavelengths Which of the following isolates light within a narrow region of the spectrum? A. Photomultiplier tube B. Monochromator C. Photovoltaic cell D. Detector - CORRECT ANSWER-B Use for selecting a narrow band wavelengths from a continuous spectrum. Three kinds (prisms, filters, diffraction gratings. Which of the following is not descriptive of a photomultiplier tube? A. Emits electrons proportionally to initial light absorbed B. Must be shielded from stray light C. Cannot be used with a chopper D. Amplifies the initial signal received - CORRECT ANSWER-C PMT- responds to the radiant energy light it absorbs by emitting electrons in a proportional amount to the initial light absorbed. Which of the following is false about a photomultiplier tube? A. Converts radiant energy (light) to electrical energy (current) B. Amplifies the current significantly C. Has a very rapid response time D. Is composed of an iron plate and a layer of selenium - CORRECT ANSWER-D is part of a barrier layer cell PMT- 1. light to electricity 2. Amplification 5. Which type of photodetector employs a linear arrangement that allows it to respond to a specific wavelength resulting in complete UV/visible spectrum analysis? A. Photomultiplier tube B. Phototube C. Barrier layer cell D. Photodiode array - CORRECT ANSWER-D 256-2048 arranged in a linear fashion Respond to a specific wavelength that results in a continuous UV/ visible spectrum. When performing spectrophotometer quality assurance checks, what is the holmium oxide glass filter used to assess? A. Linearity B. Stray light C. Absorbance accuracy D. Wavelength accuracy - CORRECT ANSWER-D In spectrophotometric analysis, what is the purpose of the reagent blank? A. Correct for interfering chromogens B. Correct for lipemia C. Correct for protein D. Correct for color contribution of the reagents - CORRECT ANSWER-D In regard to bichromatic analysis, which of the following is false? A. Absorbance is measured at the spectral absorbance peak for a blank and the sample using the same wavelength. B. Eliminates background interferences C. Sample concentration determined from difference in two measured absorbances D. Functions as a reference blank for each sample - CORRECT ANSWER-A The bandpass of a spectrophotometer is 10 nm. If an instalment is set at 540 nm, the wavelengths that are permitted to impinge on the sample will be within what wavelength range? A. 530-540 nm B. 530-550 nm C. 535-545 nm D. 540-550 nm - CORRECT ANSWER-C 540 +/- 5nm (10nm) Which of the following formulas is an expression of the Beer-Lambert law that is routinely applied to spectrophotometric analysis? A. A u X C s/As = C u B. C u X C s/As= A u C. A s X C s/C u = A u D. A = 2 - log %T - CORRECT ANSWER-A 1 1 . In spectrophotometry, which of the following is a mathematical expression of the relationship between absorbance and transmittance? A. A — abc R A u/ C u = A s/C s C. A = 2 - log %T D. A = log %T - CORRECT ANSWER-C Which of the following is not a problem inherent in turbidimetry? A. Variation in particle size of samples B. Variation in particle size of standards C. Rate of aggregation or settling of particles D. Need to maintain a constant and specific temperature - CORRECT ANSWER-D Which of the following may be asso- ciated with reflectance spectrophotometry as it relates to the dry reagent slide technique? A. Light projected to the slide at 180-degree angle B. Dye concentration directly proportional to reflectance C. Unabsorbed, reflected light detected by photodetector D. Reflectance values are linearly proportional to transmission values - CORRECT ANSWER-C Fluorometers are designed so that the path of the exciting light is at a right angle to the path of the emitted light. What is the purpose of this design? A. Prevent loss of emitted light B. Prevent loss of the excitation light C. Focus emitted and excitation light upon the detector D. Prevent excitation light from reaching the detector - CORRECT ANSWER-D Which of the following represents a primary advantage of performing fluorometric over absorption spectro- scopic methods of analysis? A. Increased specificity and increased sensitivity B. Increased specificity and decreased sensitivity C. Purity of reagents used not as critical D. Ease of performing assays - CORRECT ANSWER-A Which of the following may be associated with fluorescence polarization? A. Plane-polarized light is used for sample excitation. B. Small molecular complexes show a greater amount of polarization. C. It is a heterogeneous technique employed in fluorophore-ligand immunoassays. D. Polarized light detected is directly proportional to concentration of ligand in sample. - CORRECT ANSWER-A Which of the following may be associated with bioluminescence? A. Light emission produced due to enzymatic oxidation of a substrate B. Less sensitive than direct fluorescent assays C. Electron excitation caused by radiant energy D. Employs a radioactive label - CORRECT ANSWER-A 18. Nephelometry is based on the measurement of light that is A. Absorbed by particles in suspension B. Scattered by particles in suspension C. Produced by fluorescence D. Produced by excitation of ground-state atoms - CORRECT ANSWER-B Which of the following instruments is used in the clinical laboratory or in reference laboratories to detect beta and gamma emissions? A. Fluorometer B. Nephelometer C. Scintillation counter D. Spectrophotometer - CORRECT ANSWER-C uses a crystal of sodium iodide thallium as an activator (gamma) Which of the following best describes chemiluminescence? A. Electron excitation caused by radiant energy B. Enzymatic oxidation of a substrate produces light emission C. Chemical energy excites electrons that emit light upon return to ground state D. Employs a fluorescent label that produces light - CORRECT ANSWER-C In assaying an analyte with a single-beam atomic absorption spectrophotometer, what is the instrument actually measuring? A. Intensity of light emitted by the analyte on its return to the ground state B. Intensity of light that the analyte absorbs from the hollow-cathode lamp C. Intensity of light that the analyte absorbs from the flame D. Intensity of the beam from the hollow-cathode lamp after it has passed through the analyte-containing flame - CORRECT ANSWER-D AAS- atoms at ground state are capable of absorbing energy in the form of light at a specific wavelenght What is the function of the flame in atomic absorption spectroscopy? A. Absorb the energy emitted from the metal analyte in returning to ground state B. Supply the thermal energy needed to excite the metal analyte C. Bring the metal analyte to its ground state D. Supply the light that is absorbed by the metal analyte - CORRECT ANSWER-C Most atomic absorption spectrophotometers incorporate a beam chopper and a tuned amplifier. The purpose of these components is to avoid errors that would be caused by A. Variations in flame temperature B. Deterioration of the hollow-cathode lamp C. Stray light from the hollow-cathode lamp D. Measurement of light emitted by the analyte - CORRECT ANSWER-D In potentiometry, which of the following is considered the standard electrode? A. Hydrogen electrode B. Calcium electrode C. Potassium electrode D. Copper electrode - CORRECT ANSWER-A In an electrolytic cell, which of the following is the half-cell where reduction takes place? A. Anode B. Cathode C. Combination electrode D. Electrode response - CORRECT ANSWER-B Mercury covered by a layer of mercurous chloride in contact with saturated potassium chloride solution is a description of which of the following types of electrodes? A. Sodium B. Calomel C. Calcium D. Silver/silver chloride - CORRECT ANSWER-B When a pH-sensitive glass electrode is not actively in use, in what type of solution should it be kept? A. Tap water B. Physiologic saline solution C. The medium recommended by the manufacturer D. A buffer solution of alkaline pH - CORRECT ANSWER-C When measuring K + with an ion-selective electrode by means of a liquid ion-exchange membrane, what antibiotic will be incorporated into the membrane? A. Monactin B. Nonactin C. Streptomycin D. Valinomycin - CORRECT ANSWER-D Which of the following is false about ion-selective electrode analysis of sodium? A. Uses a glass membrane B. Errors occur from protein buildup on the membrane. C. Membrane coated with valinomycin D. Principle based on potentiometry - CORRECT ANSWER-C What are the principles of operation for a chloride analyzer that generates silver ions as part of its reaction mechanism? A. Potentiometry and amperometry B. Amperometry and polarography C. Coulometry and potentiometry D. Amperometry and coulometry - CORRECT ANSWER-D When quantifying glucose using an amperometric glucose electrode system, which of the following is not a component of the system? A. Product oxidation produces a current B. Hydrogen peroxide formed C. Hexokinase reacts with glucose D. Platinum electrode - CORRECT ANSWER-C amperometric glucose= glucose oxidase reacts with glucose= hydrogen peroxide and gluconic acid. 32. To calibrate the pH electrode in a pH/blood gas analyzer, it is necessary that A. The barometric pressure be known and used for adjustments B. Calibrating gases of known high and low concentrations be used C. The calibration be performed at room temperature D. Two buffer solutions of known pH be used - CORRECT ANSWER-D The measurement of CO 2 in blood by means of a PCO 2 electrode is dependent on the A. Passage of H + ions through the membrane that separates the sample and the electrode B. Change in pH because of increased carbonic acid in the electrolyte surrounding the electrodes C. Movement of bicarbonate across the membrane that separates the sample and the electrode