ASCP chemistry TEST QUESTIONS ACCURATE TESTED VERSIONS OF THE EXAM FROM 2024, Exams of Chemistry

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ASCP chemistry TEST QUESTIONS

ACCURATE TESTED VERSIONS OF THE

EXAM FROM 2023TO 2024 | ACCURATE

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QUESTIONS

In which of the following disease states in conjugated bilirubin a major serum component - ANSWER biliary obstruction Kernicterus is an abnormal accumulation of bilirubin in

• ANSWER brain tissue In which of the following conditions does decreased activity of glucuronyl transferase result in increased unconjugated bilirubin and kernicterus in neonates
• ANSWER crigler-najjar syndrome A 21 year old man with nausea, vomiting, and jaundice has the following laboratory findings Total serum bilirubin 8.5 mg/dL (0-1.0) conjugated serum bilirubin 6.1 mg/dL (0-0.5) urine urobilinogen increased fecal urobilinogen decreased urine bilirubin positive AST 300 U/L (0-50)

alkaline phosphatase 170 U/L(0-150) These can best be explained as representing

• ANSWER conjugated hyperbilirubinemia, probably due to hepatocellular obstruction hepatocellular disorder and highly elevated AST Biochemical profile of a patient total protein 7.3 g/d: (6-8.0) albumin 4.1 g/dL (3.5-5.0) calcium 9.6 mg/dL (8.5-10.5) phosphorous 3.3 mg/dL (2.5-4.5) glucose 95 mg/dL (65-110) BUN 16 mg/dL (10-20) uric acid 6.0 mg/dL (2.5-8.0) creatinine 1.2 mg/dL (0.7-1.4) total bilirubin 3.7 mg/dL (0.2-0.9) alkaline phosphatase 275 U/L (30-80) lactate dehydrogenase 185 U/L (100-225) AST 75 U/L (10-40) The results in the biochemical profile are most consistent with
• ANSWER common bile duct stone post-hepatic biliary obstruction; increased AST

A stool specimen that appears black and tarry should be tested for the presence of

• ANSWER occult blood What substance gives feces its normal color
• ANSWER urobilin pigments are uro-, meso-, stercobilin (in feces) A condition in which erythrocyte protoporphyrin is increased is
• ANSWER iron deficiency anemia Which of the following elevates carboxyhemoglobin
• ANSWER exposure to carbon monoxide The reason carbon monoxide is so toxic is because it
• ANSWER has 200 times the affinity for oxygen for hemoglobin binding sites CO prevents heme iron from binding with oxygen Detection of carriesers of hereditary coproporphyria should include analysis of
• ANSWER fresh morning urine for delta-aminolevulinic acid A fresh urine sample is received for analysis for "porphyrins" or "porphyria" without further information of specifications. Initial analysis should include
• ANSWER porphyrin and porphobilinogen screen Which of the following enzymes of heme biosynthesis is inhibited by lead

• ANSWER porphobilinogen synthase Serum haptoglobin can be
• ANSWER separated into distinct phenotypes by starch-gel electrophoresis The most specific enzyme test for acute pancreatitis is
• ANSWER lipase There is an increase in the serum levels of amylase and lipase in acute pancreatitis. However, elevated levels of lipase persist longer than amylase Which of the following enzymes are used in the diagnosis of acute pancreatitis
• ANSWER amylase (AMS) and lipase (LPS) amylase and lipase are hydrolases involved in the breakdown of starch and glycogen, and lipid metabolism respectively. Both enzymes are primarily located in the pancreas. Which of the following enzymes catalyzes the conversion of starch to glucose and maltose - ANSWER amylase (AMS) Which of the following sets of results would be consistent with macroamylasemia
• ANSWER increased serum amylase and normal urine amylase values A physician suspects his patient has pancreatitis. Which test(s) would be most indicative of this disease
• ANSWER amylase Aspartate amino transferase (AST) is characteristically elevated in diseases of the:

• ANSWER liver Amino transferase enzymes catalyze the
  • ANSWER exchange of amino and keto groups between alpha-amino and alpha-keto acids Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are both elevated in which of the following diseases
• ANSWER viral hepatitis ALT and AST are located primarily in the liver. ALT level is usually higher than AST. Increased levels of AST are also seen in infectious mononucleosis and muscular dystrophy while ALT is not elevated in the clinical disorders The greatest activities of serum AST and ALT are seen in which of the following
• ANSWER acute viral hepatitis Malic dehydrogenase is asses to the aspartate aminotransaminase (AST) reaction to catalyze the conversion of
  • ANSWER oxalacetate to malate Given the following results, this is most consistent with alkaline phosphatase slight increase aspartate amino transferase marked increase alanine amino transferase marked increase gamma-glutamyl transferase slight increase – ANSWER acute hepatitis

Which of the following clinical disorders is associated with the greatest elevation of lactate dehydrogenase isoenzyme 1

• ANSWER pernicious anemia elevated serum levels of LD up to 50 times the upper limit of normal are seen with pernicious anemia. The ineffective erythropoiesis results in the release of large quantities of LD1 and LD2. Increased levels may be seen in renal disease, but the increase is not as great as for pernicious anemia. If LD3 is increased, it is indicative of pulmonary conditions and pancreatitis The enzyme, which exists chiefly in skeletal muscle, heart, and brain, is grossly elevated in active muscular dystrophy, and rises early in myocardial infarction is
• ANSWER creatine kinase The enzyme present in almost all tissues that may be separated by electrophoresis into 5 components is
• ANSWER lactate dehydrogenase A common cause of falsely increased LD1 fraction of lactate dehydrogenase is – ANSWER specimen hemolysis RBCs contain 150 times more LD activity than serum. LD5 is increased in liver disorders and drug toxicity if the liver is involved The presence of which of the following isoenzymes indicates indicates acute myocardial damage
• ANSWER CKMB In which of the following conditions would a NORMAL level of creatinine kinase be found - ANSWER hepatitis CK is located in the brain tissue, heart, and skeletal muscle. CK is not increased in liver issues

Of the following diseases, the one most often associated with elevation of lactate dehydrogenase isoenzymes 4 and 5 on electrophoresis is

• ANSWER liver disease When myocardial infarction occurs, the first enzyme to become elevated is
• ANSWER CK A scanning of a CK isoenzyme fractionation revealed 2 peaks: a slow cathodic peak (CKMM) and an intermediate peak (CKMB). A possible interpretation for this pattern is
  • ANSWER myocardial infarction An electrophoretic separation of lactate dehydrogenase isoenzymes that demonstrates an elevation in LD1 and LD2 in a "flipped" pattern is consistent with
  • ANSWER myocardial infarction Increased total serum lactic dehydrogenase (LD) activity, confined to fractions 4 and 5 is most likely to be associated with - ANSWER acute viral hepatitis A 10-year old child was admitted to pediatrics with an initial diagnosis of skeletal muscle disease. The best confirmatory tests would be - ANSWER aldolase and creatinine kinase In the immunoinhibition phase of CKMB procedure - ANSWER M unit is inactivated Antibodies are directed against the M and B units of the enzymes. Anti-M inhibits all M activity but not B. Measurements are taken before and after inhibition and the activity remaining after inhibition is a result of B subunit for BB and MB activity. The presence of increased CKMB activity on a CK electrophoresis pattern is most likely found in a patient suffereing from - ANSWER myocardial infarction

With a chart showing the 5 peaks of LD, and peak 5 is the highest, what is the condition - ANSWER viral hepatitis Increased serum lactic dehydrogenase activity due to elevation of fast fraction (1 and 2) on electrophoretic separation is caused by - ANSWER hemolytic anemia A serum sample drawn in the emergency room from a 42 year old man yielded the following laboratory results: CK 185 U/L (15-160) AST 123 U/L (0-48) CKMB 6 U/L (2-12) Which of the following might account for these values - ANSWER crush injury to the thigh Elevations in CK and AST is seen in muscle damage due to the crush injury Given the following results this is most consistent with alkaline phosphatase marked increase aspartate amino transferase slight increase alanine amino transferase slight increase gamma-glutamyl transferase marked increase - ANSWER obstructive jaundice *signaled by the increased ALP and increase in GGT Given the following results this is most consistent with

alkaline phosphatase slight increase aspartate aminotransferase slight increase alanine aminotransferase slight increase gamma-glutamyl transferase slight increase - ANSWER chronic hepatitis What specimen preparation is commonly used to perform the alkaline phosphatase isoenzyme determination - ANSWER serum is divided into 2 aliquots, one is heated at 56C and the other is unheated Regan isoenzymes has the same properties as alkaline phosphatase that originates in the - ANSWER placenta The MOST heat labile fraction of alkaline phosphatase is obtained from - ANSWER bone The MOST sensitive enzymatic indicator for liver damage from ethanol intake is - ANSWER gamma-glutamyl transferase (GGT) Isoenzyme assays are performed to improve - ANSWER specificity The protein portion of an enzyme complex is called the - ANSWER apoenzyme the holoenzyme is the active system formed by the apoenzyme Which of the following chemical determinations may be of help in establishing the presence of seminal fluid - ANSWER acid phosphatase 20 - 30% of seminal fluid is prostatic fluid and prostatic fluid is acid phosphatase, citric acid, and proteolytic enzymes

Which of the following enzyme substrates is the most specific for prostatic acid phosphatase for quantitative endpoint reactions - ANSWER thymolphalein monophosphate Lactate dehydrogenase, malate dehydrogenase, and hydroxybutyrate dehydrogenase all: - ANSWER catalyze oxidation-reduction reactions High levels of which lipoprotein classare associated with decreased risk of accelerated atheroschlerosis - ANSWER HDL This is the "good" kind The most consistent analytical error involved in the routine determination of HDL-cholesterol is caused by - ANSWER a small concentration of apoB-containing lipoproteins afterprecipitation If the LDL-cholesterol is to be calculated by the Friedwald formula, what are the 2 measurements that need to be carried out by the same chemical procedure - ANSWER total cholesterol and HDL cholesterol The chemical composition of HDL-cholesterol corresponds to Triglyceride cholesterol protein 60 15 10 10 45 25 5 15 50 85 5 2 - ANSWER 5% triglyceride, 15% cholesterol, 50% protein In familial hypercholesterolemia, the hallmark finding is an elevation of - ANSWER LDL (low density lipoproteins)

Premature atherosclerosis can occur when which of the following becomes elevated - ANSWER low-density lipoproteins Transportation of 60-75% of the plasma cholesterol is performed by - ANSWER low-density lipoproteins Which of the following diseases results from a familial absence of high density lipoprotein - ANSWER Tangier disease A 1-year old girl with a hyperlipoproteinemia and lipase deficiency has the following lipid profile: Cholesterol 300mg/dL LDL increased HDL decreased triglycerides 200mg/dL chylomicrons present A serum specimen from this patient that was refrigerated overnight would most likely be - ANSWER creamy layer over clear serum Which of the following lipid results would be expected to be falsely elevated on a serum specimen from a nonfasting patient - ANSWER triglyceride A 9-month old boy from Israel has gradually lost the ability to sit up, and develops seizures. He has an increased amount of a phospholipid called GM2-ganglioside in his neurons, and he lacks the enzyme hexosaminidase A in his leukocytes. These findings suggest - ANSWER Tay-sachs disease

In amniotic fluid, the procedure used to determine fetal lung maturity is - ANSWER lecithin/sphingomyelin ratio The class of phospholipis surfactants represented by the dotted line on the amniotic fluid analysis shown above is thought to originate in what fetal organ system (the dotted line is above the solid and has a higher peak as gestation progresses) - ANSWER pulmonary A fasting serum sample from an asymptomatic 43-year-old woman is examined visually and chemically with the following results initial appearance of serum:milky appearance of serum after overnight refrigeration: creamy layer over turbid serum Triglyceride level: 2,000 mg/dL Cholesterol level: 550 mg/dL The sample contains predominantly - ANSWER chylomicrons and VLDL Chylomicrons are present in which of the following dyslipidemias - ANSWER deficiency in lipoprotein lipase activity The function of the major lipid components of VLDL is to transport - ANSWER endogenous triglycerides Turbidity in serum suggests elevation of - ANSWER chylomicrons TSH is produced in the - ANSWER pituitary gland A patient has the following thyroid profile

Total T4 decreased Free T4 decreased Thyroid peroxidase antibody positive TSH decreased This patient most probably has - ANSWER hypothyroidism A 45-year old woman complains of fatigue, heat intolerance and hair loss. Total and free T4 are abnormally low. If the TSH showed marked elevation, this would be consistent with - ANSWER hypothyroidism The majority of thyroxine (T4)is converted into the more biologically active hormone - ANSWER triiodothyronine (T3) 80% of T4 is converted into T3 (the more biologically active) A 2-year-old child with a decreased serum T4 is described as being somewhat dwarfed, stocky, overweight, and having coarse features. Of the following, the most informative additional laboratory test would be the serum - ANSWER TSH Assays for free T4 measure hormone not bound to thyroxine-binding prealbumin, thyroxine- binding globulin and - ANSWER albumin The recommended initial thyroid function test for either a healthy, asymptomatic patient or a patient with symptoms which may be related to a thyroid disorder is - ANSWER TSH The screening test for congenital hypothyroidism is based upon - ANSWER T4 level in the newborn

Which one of the following sets of results is consistent with primary hypothyroidism (hashimoto's thyroiditis) Results TSH T4 antimicrobial antibody A decreased decreased + B increased increased + C normal decreased = D increased decreased + - ANSWER result D hashimoto's is the most common cause of hypothyroidism A 68-year-old female patient tells her physician of being "cold all the time" and recent weight gain, with no change in diet. The doctor orders a TSH level, and the laboratory reports a value of 8.7 uU/mL (0.5-5.0). This patient most likely has - ANSWER primary hypothyroidism Which of the following is secreted by the placenta and used for the early detection of pregnancy

• ANSWER HCG During pregnancy, the form of estrogen measured in urine is mostly - ANSWER estriol estradiol is for ovulation The HCG levels shown in the above graph most probably represent (The graph increases onto month 2 then slightly decreases and it then steady) - ANSWER normal pregancy In amniotic fluid, the procedure used to detect hemolytic disease of the newborn is - ANSWER measurement of absorbance at 450 nm

During a normal pregnancy, HCG levels peak how many weeks after the last menstrual period - ANSWER 8-10 weeks "laboratory A" measures maternal serum alpha-fetoprotein (MSAFP) at 16-18 weeks gestation as a screen for fetal disorders. The 16 week MSAFP median for Lab A is 32ug/L. A 37 year old woman has an MSAFP level of 34 at her 16th week. This result is consistent with - ANSWER normal level for 16 week. 34/32=1.06 (<2) Which of the following steroids is an adrenal cortical hormone - ANSWER aldosterone What common substrate is used in the biosynthesis of adrenal steroids, including androgens and estrogens - ANSWER cholesterol The biologically most active, naturally occurring androgen is - ANSWER testosterone Plasma for cortisol determinations were collected at 7AM, after waking the patient, and at 10PM that evening. The cortisol level of the morning sample was higher than the evening sample. This is consistent with - ANSWER a normal finding Night blindness is associated with deficiency of which of the following vitamins - ANSWER vitamin A Beriberi is associated with deficiency of vitamin - ANSWER thiamine (B1)- also seen with chronic alcoholism Scurvy is associated with deficiency of which vitamin - ANSWER vitamin C (ascorbic acid) Rickets is associated with deficiency of which vitamin - ANSWER vitamin D

Pellagra is associated with deficiency of which vitamin - ANSWER niacin-seen with chronic alcoholism The major action of angiotensin II is - ANSWER increased vasoconstriction stimulates the adrenal cortex to produce aldosterone The urinary excretion product measured as an indicator of epinephrine production is - ANSWER VMA- major metabolite of epinephrine and norepinephrine Which of the following hormones regulates normal blood calcium levels - ANSWER PTH The most common form (95%) of congenital adrenal hyperplasia is 21-hydroxylase deficiency, which is detected by elevated plasma - ANSWER 17-OH-progesterone A diagnosis of primary adrenal insufficiency requires demonstration of - ANSWER impaired response to ACTH stimulation The screen for adrenal cortical hyperfunction with the greatest sensitivity and specificity is: - ANSWER 24 hour urine free cortisol A patient has signs and symptoms suggestive of acromegaly. The diagnosis would be confirmed if the patient has which of the following - ANSWER no decrease in serum growth hormone releasing factor concentration Estrogen and progesterone receptor assays are useful in identifying patients who are likely to benefit from endocrine therapy to treat which of the following - ANSWER breast cancer

Which of the following sample collections would give an accurate assessment of potential excess cortisol production (hypercortisolism) - ANSWER collect a 24-hour urine free cortisol How is primary hypocortisolism differentiated from secondary hypocortisolism - ANSWER adrenal corticotropic hormone (ACTH) is elevated in primary and decreased in secondary Aldosterone is released by the adrenal cortex upon stimulation by - ANSWER angiotensin II In developing the reference for a new EIA for CEA, the range for the normal population was broader than that published by the vendor. Controls are acceptable with a narrow coefficient of variation. This may be explained by: - ANSWER inclusion of nonsmokers and smokers in the study population Increased CEA is found in patients with liver damage, heavy smokers, and following radiation/chemotherapy Clinical assays for tumor markers are most important for - ANSWER monitoring the coarse of a known cancer monitoring therapy, detecting recurrence and aiding in the prognosis of tumors Detection of which of the following substances is most useful to monitor the course of a patient with testicular cancer - ANSWER alpha-fetoprotein It is a marker for colon cancer Increased concentrations of alpha-fetoprotein in adults are most characteristically associated with - ANSWER hepatocellular carcinoma seen in hepatitis and cirrhosis

Carcinoembryonic antigen (CEA) is most likely to be produced in a malignancy involving the - ANSWER colon Which of the following is useful in the detection and management of carcinoma of the prostate

• ANSWER total prostate specific antigen Which of the following statements most correctly describes the utility of clinical laboratory assays for tumor markers - ANSWER tumor markers are useful in tracking the efficacy of treatment Cancer antigen 125 (CA 125) is a tumor marker associated with - ANSWER ovarian and endometrial carcinoma In addition to carcinoma of the prostate, elevated prostate-specific antigen (PSA) can occur due to - ANSWER benign prostatic hyperplasia Blood specimens for digoxin assays should be obtained between 8 hours or more after drug administration because - ANSWER tissue and serum levels need to reach equilibrium A drug has a half-life of 6 hours. If a dose is given every 6 hours, a steady-state drug level would usually be achieved in - ANSWER 24-42 hours. 4 - 7 doses Free therapeutic drug levels are usually higher when serum protein concentrations are below normal. In Which of the following conditions would this most likely occur - ANSWER nephrotic syndrome Which of the following factors is not relevant to therapeutic drug monitoring (TDM) of the aminoglycosides, antibiotics and vancomycin - ANSWER intestinal absorption

ones involved and relevant: nephrotoxicity, ototoxicity, and renal function The drug procainamide is prescribed to treat cardiac arrhythmia. What biologically active liver metabolite of procainamide is often measured simultaneously - ANSWER N-acetyl procainamide (NAPA) Cocaine is metabolized to - ANSWER benzoylecgonine The metabolite 11-nor-tetrahydrocannabinol- 9 - COOH can be detected by immunoassay 3- 5 days after a single use of - ANSWER marijuana A 3-year-oldchild was evaluated for abdominal pain and anorexia by a physician. A CBC revealed a hemoglobin of 9.8 g/dL and basophilic stippling of the RBCs. The doctor should order further tests to check for poisoning from - ANSWER lead Zinc protoporphyrin or free erythrocyte protoporphyrin measurements are useful to assess blood concentrations of - ANSWER lead A carbonate salt used to control manic-depressive disorders is - ANSWER lithium An antiepileptic (or anticonvulsant) used to control seizure disorders is - ANSWER phenytoin A drug that relaxes the smooth muscles of the bronchial passages is - ANSWER theophylline A cardiac glycoside that is used in the treatment of congenital heart failure and arrhythmias by increasing the force and velocity of myocardial contraction is - ANSWER digoxin A salicylate level is performed to detect toxicity caused by ingestion of excess - ANSWER aspirin

Lithium therapy is widely used in the treatment of - ANSWER manic-depressive (bipolar) disorder Serum and urine copper levels are assayed on a hospital patient with the following results Serum Cu 20 ug/dL (70-140) Urine Cu 83 ug/dL (<40) This is most consistent with - ANSWER Wilson's disease An active metabolite of amitriptyline is - ANSWER notriptyline Phenobarbital is a metabolite of - ANSWER primidone Testing for the diagnosis of lead poisoning should include - ANSWER whole blood lead Blood received in the laboratory for blood gas analysis must meet which of the following requirements - ANSWER on ice, no clots, no air bubbles After a difficult venipuncture requiring prolonged application of the tourniquet, the serum K+ was found to be 6.8 mmol/L. The best course of action is to - ANSWER repeat the test using freshly drawn serum Serum from a patient with metastatic carcinoma of the prostate was separated from the clot and stored at room temperature. The following results were obtained Ca++ 10.8 mg/dL (8.8-10.3) LD 420 U/L (50-150)

acid phosphatase 0.1 U/L (0-5.5) The technician should repeat the - ANSWER acid phosphatase with freshly drawn serum acid phosphatase measurements should not be stored at room temperature A lipemic serum is separated and frozen at - 20C for assay at a later date. One week later, prior to performing an assay for triglycerides, the specimen should - ANSWER warmed to 37C and mixed thoroughly The different water content of erythrocytes and plasma makes true glucose concentrations in whole blood a function of the - ANSWER hematocrit water content is higher in plasma than whole blood In a specimen collected for plasma glucose analysis, sodium fluoride: - ANSWER inhibits glycolysis As part of a hyperlipidemia screening program, the following results were obtained on a 25- year-old woman 6 hours after eating Triglycerides 260 mg/dL Cholesterol 120 mg/dL Which of the following is the BEST interpretation of these results - ANSWER cholesterol is normal but the triglycerides are elevated which may be attributed to the recent meal Blood was collected in a serum separator tube on a patient who has been fasting since midnight. The time of collection was7 AM. The laboratory test which should be recollected is - ANSWER triglycerides

Arterial blood that is collected in a heparinized syringe but exposed to room air would be most consistent with the changes in which of the following specimens Specimen PO2 PCO2 pH A high low high B low high low C same high same D low low low - ANSWER specimen A Specimens for blood gas determination should be drawn into a syringe containing - ANSWER heparin Unless blood gas measurements are made immediately after sampling, in vitro glycolysis of the blood causes a - ANSWER fall in pH and rise in PCO2 failure to adequately chill blood gas specimens if not immediately analyzed will allow glucose metabolism, which increases carbon dioxide and lowers pH Which of the following serum constituents is unstable if a blood specimen is left standing at room temperature for 8 hours before processing - ANSWER glucose An arterial blood specimen submitted for blood gas analysis was obtained at 9:30 AM but was not received in the laboratory until 11AM. The technologist should: - ANSWER request a new arterial specimen be obtained In monitoring glomerular function, which of the following tests has the highest sensitivity - ANSWER Creatinine clearance

If the pKa is 6.1, the CO2 content is 25mM/L, the salt equals the total CO2 content minus the carbonic acid; the carbonic acid equals 0.03 x PCO2 and PCO2 = 40 mm Hg, it may be concluded that - ANSWER pH=6.1 + log [(25-1.2)/(1.2)] --> from the book but the total CO2 content isn't 1.2 it's 0.3 which would make the answer pH=6.1 + log [(25- 0.03)/(0.03)] pH= 6.1+ log (salt/acid) salt=total CO2- carbonic acid A 24 hour urine specimen (total volume =1,136mL) is submitted to the laboratory for quantitative urine protein. Calculate the amount of protein excreted per day, if the total protein is 52 mg/dL - ANSWER 591 mg 52 mg/dL= 0.52 mg/mL Therefore 0.52 mg/mL x 1136 = 590.72-->591 the following results were obtained Urine creatinine 90 mg/dL Serum creatinine 0.90 mg/dL Patient's total body surface 1.73 m2 Total urine volume in 24 hours 1500 mL Given the above data, the patient's creatinine clearance, in mL/min is: - ANSWER 104 creatinine clearance= (urine creatinine x volume (mL/min))/serum creatinine x 1.73/total body surface area creatinine clearance= (90 x 1.04 [ 1500/1440]/.90) = 104

A 45-year old male average height and weight was admitted to the hospital for renal function studies. He had the following lab results Urine creatinine 120 mg/dL Serum creatinine 1.5 mg/dL total urine volume in 24 hours 1800/mL What is the creatinine clearance in mL/min - ANSWER 100 Creatinine clearance= urine creatinine x volume [mL/min]/serum creatinine creatinine clearance= 120 x [1800/1440] / 1.5 = 100 One international unit of enzyme activity is the amount of enzyme that will, under specified reaction conditions of substrate concentration, pH and temperature cause utilization of substrate at the rate of - ANSWER 1 umol/min The bicarbonate and carbonic acid ratio is calculated from an equation by - ANSWER Henderson-hasselbalch 125I has a physical half-life of 60.0 days. A sample tested today had activity of 10,000 CPM/mL. How many days from today will the count be 1250 CPM/mL - ANSWER 180 t=1.44 x t 1/2 x ln (original activity / remaining activity) In spectrophotometric determination, which of the following is the formula for calculating the absorbance of a solution - ANSWER absorptivity x light path x concentration

Which of the following is the formula for calculating absorbance given the percent transmittance of a solution - ANSWER 2-log %T Which of the following is the henderson-hasselbalch equation - ANSWER pH=pKa + log([salt]/[acid]) The creatinine clearance (mL/min) is equal to - ANSWER urine creatinine x volume in mL/min / serum creatinine An adult diabetic with renal complications has the following results sodium 133 mEq/L glucose 487 mg/dL BUN 84 mg/dL creatinine 5 mg/dL On the basis of these results, the calculated serum osmolality is - ANSWER 323 mOsm/kg calculated osmolality= 2 x Na + (glucose/18) + (BUN/2.8) The above figure shows the reciprocal of the measured velocity of an enzyme reaction plotted against the reciprocal of the substrate concentration. True statements about this figure include - ANSWER The intercept n the abscissa (x-axis) can be used to calculate the michaelis-Menten constant The following results were obtained in a creatinine clearance evaluation urine concentration 84 mg/dL urine volume 1440/24 hours serum concentration 1.4 mg/dL