Download Clinical Chemistry I ASCP review (youlazy) and more Exams Chemistry in PDF only on Docsity!
Clinical Chemistry I ASCP review
(youlazy)
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 - ANS>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 - ANS>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 - ANS>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 - ANS>D is part of a barrier layer cell PMT- 1. light to electricity
- Amplification
B. Correct for lipemia C. Correct for protein D. Correct for color contribution of the reagents - ANS>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 - ANS>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 - ANS>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 - ANS>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 - ANS>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 - ANS>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 - ANS>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. - ANS>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 - ANS>A
- 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 - ANS>B
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 - ANS>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 - ANS>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 - ANS>D In potentiometry, which of the following is considered the standard electrode? A. Hydrogen electrode B. Calcium electrode C. Potassium electrode D. Copper electrode - ANS>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 - ANS>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?
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 - ANS>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 - ANS>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 - ANS>C amperometric glucose=> glucose oxidase reacts with glucose=> hydrogen peroxide and gluconic acid.
- 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 - ANS>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 D. Linear relationship between PCO2 in the sample and measured pH - ANS>B pH electrode immersed in a bicarbonate solution. separated by a membrane that only allows CO
B. Occurs in an electrochemical cell C. Involves preconcentration of the analyte by electroplating D. Used to measure lead - ANS>A
- Which of the following methods allows for the separation of charged particles based on their rates of migration in an electric field? A. Rheophoresis B. Electrophoresis C. Electroendosmosis D. Ion exchange - ANS>B
- Which of the following techniques is based on electro-osmotic flow? A. Capillary electrophoresis B. Zone electrophoresis C. Iontophoresis D. Isoelectric focusing - ANS>A
- Which of the following is not a type of support media used for serum protein electrophoresis? A. Agarose gel B. Cellulose acetate
C. Acrylamide D. Celite - ANS>D Celite- inert supporting phase in gas-liquid chromatography
- In serum protein electrophoresis, when a buffer solution of pH 8.6 is used, which of the following characterizes the proteins? A. Exhibit net negative charge B. Exhibit net positive charge C. Exhibit charge neutrality D. Migrate toward the cathode - ANS>A migrate towards the anode gamma globulins shows endosmosis
- Which of the following characteristics will a protein have at its isoelectric point? A. Net negative charge B. Net positive charge C. Net zero charge D. Mobility - ANS>C
A. Maintain the polyacrylamide gel in a solid state B. Maintain the protein sample in a charged state C. Maintain the pH of the buffer solution D. Establish a pH gradient in the gel - ANS>D
- Which of the following is not associated with silver stains? A. Reactive to nanogram concentrations of proteins B. Polypeptides stain a variety of colors C. Not as sensitive as Coomassie brilliant blue D. Preconcentration of CSF not necessary - ANS>C
- Which of the following is not associated with isoelectric focusing? A. Continuous pH gradient B. Migration of proteins with net charge of zero C. Separation dependent on isoelectric point D. Zone electrophoresis - ANS>B
- Which of the following is an electrophoretic technique employing a pH gradient that separates molecules with similar isoelectric points? A. Zone electrophoresis B. High-resolution electrophoresis C. Isoelectric focusing D. Immunoelectrophoresis - ANS>C
- Given the following information on a particular compound that has been visualized by means of thin-layer chromatography, calculate the /fyof the compound. Distance from origin to spot center = 48 mm Distance from spot center to solvent front = 93 mm Distance from origin to solvent front = 141 mm A. 0. B. 0. C. 0. D. 0.66 - ANS>B
