Chemistry Review 201-300

Which of the following disorders is characterized by an inability to transport bilirubin from the sinusoidal membrane into the hepatocyte?

D. Gilbert syndrome

Which of the following disorders is NOT characterized by an elevated serum myoglobin?

D. Hepatitis

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B. The elevated results are from the skeletal muscle injuries sustained in the car crash.

Which of the following statements concerning creatine kinase is FALSE?

C. Requires Ca2+ for activity

Which of the following results would be the most consistent with high risk for coronary heart disease?

A. 20 HDL, 250 Total

Which of the following disorders can be classified as a form of prehepatic jaundice?

A. Acute hemolytic anemia

A 42 year old presents with anorexia, nausea, fever, icterus of the skin and mucous membranes. He noticed that his urine appeared dark. Results Alkaline phosphatase= slightly elevated Alanine aminotransferase=markedly elevated Aspartate aminotransferase=markedly elevated Gamma glutamyltransferase=slightly elevated Total bilirubin=moderately elevated Urine bilirubin=positive Fecal urobilirubin=decreased

A. Acute hepatitis

Which of the following functions as a transport protein for bilirubin in the blood?

A. Albumin

In the condition kernicterus, the abnormal accumulation of bilirubin occurs in what tissue?

A. Brain

To aid in the diagnosis of skeletal muscle disease, which of the following serum enzyme measurements would be of most use?

A. Creatine kinase

Which of the following is a spectrophotometric method for quantifying serum chloride?

A. Ferric perchlorate

If elevated, which of the following is associated with increased risk for coronary heart disease?

A. Homocysteine

A 46 year old known alcoholic with liver damage is brought into the emergency department unconscious. In what way would you expect his plasma lipid values to be affected?

A. Increased total cholesterol, triglyceride, LDL, VLDL

Which of the following does NOT accurately describe direct bilirubin?

A. Insoluble in water

What term is used to describe the accumulation of bilirubin in the skin?

A. Jaundice

When measuring enzyme activity if the instrument is 5 Celsius lower than the temperature prescribed for the method, how will the results be affected?

A. Lower than expected

Which of the following may be described s a variant form of LDL, associated with increased risk of atherosclerotic cardiovascular disease?

A. Lp(a)

Which of the following does NOT accurately describe the properties associated with lactate dehydrogenase?

A. Optimum pH for the catalysis of lactate to pyruvate

Use the following data NA 143 K 4.9 CL 105 HCO 25 Which of the following statements is FALSE?

A. Patient results are not acceptable

Which of the following results is LEAST consisten with a diagnosis of viral hepatitis?

A. Serum total bilirubin 7.5, direct 5.5, indirect 2.0

As the red blood cells disintegrate, hemoglobin is released and converted to the pigment bilirubin. Which organ is primarily responsible for this function?

A. Spleen

Which of the following is characteristic of hemolytic jaundice?

A. Unconjugated serum bilirubin level increased

What collective term encompasses the reduction products stercobilinogen, urobilinogen, and mesobilirubinogen?

A. Urobilinogen

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B. 1869

A patients total cholesterol is 300mg/dL, his HDL cholesterol is 50 mg/dL, and his triglyceride is 200 mg/dL. What is the patients calculated LDL cholesterol?

B. 210

For assessing carcinoma of the prostate, quantification of PSA has virtually replaced the measurement of which of the following enzymes?

B. Acid phosphatase

The laboratory receives a request that assays for urinary aminolevulinic acid, porphobilinogen, uroporphyrin, and coproporphyrin are to be performed on a patient. Which of the following will NOT contribute to the integrity of the sample when these assays are performed on the same urine specimen?

B. Addition of HCl

Which of the following enzymes does NOT belong to the class of enzymes known as the hydrolases?

B. Aldolase

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B. Amylase

In acute pancreatitis, a significant increase in which serum enzyme would be expected diagnostically?

B. Amylase

Which of the following enzymes catalyzes the transfer amino groups causing the interconversion of amino acids and alpha-oxoacids?

B. Aspartate transaminase

To quantify serum bilirubin levels, it is necessary that bilirubin couples with diazotized sulfanilic acid to form what complex?

B. Azobilirubin

Which of the following method employs a reaction where bilirubin is oxidized to colorless biliverdin?

B. Bilirubin oxidase

Which of the following is FALSE about myoglobin as it relates to acute myocardial infarction?

B. Cardiac specific

Which of the following enzymes would NOT be useful to quantify in the assessment of liver function?

B. Creatine kinase

Which of the following characterizes Crigle Najjar syndrome?

B. Deficiency of the enzyme system required for the conjugation of bilirubin.

Which of the following characterizes hepatic dysfunction in the early stage of viral hepatitis?

B. Elevation in the serum unconjugated bilirubin fraction.

The properties of enzymes are correctly described by which of the following statements?

B. Enzymes are protein catalysts of biological origin.

A 4 year old male has frequent falling, and bruising. Has difficulty running, walking, standing up, climbing and sitting up straight. The child appears weak. Which of the following is NOT consistent with the most likely diagnosis?

B. Moderately elevated ALP

The presence of only slightly visible hemolysis will significantly increase the serum level of which of the following electrolytes?

B. Potassium

In what way is the normal population reference interval for cholesterol in America different from that of other clinical chemistry paramether?

B. Reference interval is artificially set to reflect good health even though Americans as a group have "normally" high total cholesterol levels.

Which of the following statements is NOT associated with serum cholinesterase?

B. Referred to as "true" cholinesterase

The following laboratory results are determined on a patient with suggested diagnosis of biliary obstruction. Total bilirubin= increased Conjugated bilirubin= normal Urine bilirubin= increased Fecal urobilin= decreased Which laboratory result is LEAST consistent with this diagnosis?

B. Serum conjugated bilirubin

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B. Substrate concentration b

In the assay of an enzyme, zero order kinetics are best described by which of the following statements?

B. Substrate is present in excess. Rate of reaction is constant with enzyme concentration and dependant only on the concentration of the enzyme in the system.

What breakdown product of bilirubin metabolism is produced in the colon from oxidation of urobilinogen by microorganisms?

B. Urobilin

As a reduction product of bilirubin catabolism, this compound is partially reabsorbed from the intestine through the portal circulation for reexcretion by the liver. What is this compound?

B. Urobilinogen

What is the principle of the direct or homogeneous HDL cholesterol automated method, which requires no intervention by the laboratorian? The direct HDL method

B. Utilizes polymers and detergents that make the HDL cholesterol soluble while keeping the other lipoproteins insoluble.

What is the normal renal threshold of sodium?

C. 110-130

Which of the following is NOT associated with AMI?

C. Abnormal serum alkaline phosphatase isoenzyme pattern.

Which of the following disorders is NOT associated with an elevation of serum creatine kinase?

C. Bone disease

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C. CK, AST, LD

Which of the following sets of tests would be the most useful in diagnosing an AMI?

C. CK-MB, troponin, myoglobin

Indirect reacting bilirubin may be quantified by reacting it initially in which reagent?

C. Caffein - sodium benzoate

Which of the following is FALSE about cardiac troponin I as it relates to AMI?

D. Expressed in regenerating and diseased skeletal muscle and cardiac muscle disorders.

What abbreviation has been used in the past to designate alanine aminotransferase?

D. GPT

Which bilirubin fraction is unconjugated and covalently bound to albumin?

C. Delta

Which of the following reagent systems contains the components sulfanilic acid, hydrochloric acid, and sodium nitrate?

C. Diazo

A mother brings her obese 4 year old who has type 1 diabetes to the lab. She says the boy has been fasting for the past 12 hours. The serum looks turbid. Results Blood Glucose= 150 Total Cholesterol= 250 HDL= 32 Triglycerides= 395 What is the best explanation?

C. Has secondary hyperlipidemia due to the diabetes.

Which of the following techniques can be used to quantify apolipoproteins?

C. Immunophelometric assay

Which of the following is NOT characteristic of Dubin Johnson syndrome?

C. Inability to conjugate bilirubin

Which of the following statements correctly describes alkaline phosphatase?

C. Increased in obtructive jaundice

Which of the following is a TRUE statements concerning serum enzymes?

C. Increased serum alk phos may be found in bone disease.

A 53 year old patient with fatigue, pruritis, and enlarged, nontender liver has blood tests. Results Alkaline phospatase= markedly elevated Alanine aminotransferase= slightly elevated Lactate dehydrogenase= slightly elevated Gamma glutamyltransferase= markedly elevated Total bilirubin= slightly elevated

C. Intrahepatic cholestasis

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C. Lipase

A patient presents with Addison disease. Serum sodium and potassium analyses are performed. What would the results be?

C. Low sodium, High potassium

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C. Measure the increase in absorbance at 340 nm as NADH is produced.

Which of the following laboratory results is NOT characteristic of a complete obstruction of the common bile duct?

C. Negative urine bilirubin

To what class of enzymes does lactate dehydrogenase belong?

C. Oxidoreductases.

What does an increase in the serum enzyme levels indicate?

C. Tissue damage and necrosis

Which of the following statements is FALSE about the electrolyte chloride?

C. Unable to be reabsorbed by active transport

What enzyme catalyzes the conjugation of bilirubin?

C. Uridine diphosphate glucuronyltransferase

Which statement best describes the use of measuring BNP?

C. Used to assess individuals treated with nesiritide

Which of the following methods is NOT used for the quantification of serum bilirubin?

C. Zimmerman

Which test, if elevated would provide information about risk for developing coronary artery disease?

C. hs-CRP

What compound may be detected by observing its orange-red fluorescence in acid solution?

D. Coproporphyrin

Of the total serum osmolality, sodium, chloride, and bicarbonate ions normally contribute approximately what percent?

D. 92

If elevated, which laboratory test would support diagnosis of CHS?

D. BNP

A 42 year old woman admitted with abdominal pain and inability to eat, getting worse during the past 2 weeks. What alarmed her is noticing a slight yellow color in her eyes. Total bilirubin= 3.9 Direct bilirubin= 2.7 AST slightly elevated ALT slightly elevated Alkaline phosphatase markedly elevated. Urine urobilinogen decreased. Diagnosis?

D. Biliary obstruction

What is the immediate precursor of bilirubin formation?

D. Biliverdin

Which of the following conditions is not associated with hyponatremia?

D. Cushings syndrome.

What may be the cause of neonatal physiological jaundice of the hepatic type?

D. Deficiency in the bilirubin conjugation enzyme system

Which statement concerning gamma glutamyltransferase is FALSE?

D. Elevated in bone disease

A 10 year old with varicella has been experiencing fever, nausea, vomiting, lethargy, and disorientation. A diagnosis of Reye syndrome is determined. Which of the following results is NOT consistent with the diagnosis?

D. Elevated serum bilirubin

Primary aldosteronism results from a tumor of the adrenal cortex. How would the extracellular fluid be affected?

D. Increased sodium, decreased potassium

Which of the following is NOT characteristic of Cystic fibrosis?

D. Increased trypsin in feces

Which of the following is NOT a component of the total anion content of serum?

D. Iron

Which of the following is NOT associated with potassium?

D. Major anion of intracellular fluid

When measuring CKMB, which of the following would provide the most sensitive method?

D. Mass immunoassay

Which of the following disorders is NOT a form of hepatic jaundice?

D. Neoplasm in the common bile duct.

What condition is characterized by an elevation of total bilirubin primarily due to an increase in the conjugated bilirubin fraction?

D. Obstructive jaundice

A physician orders labs on a 55 year old patient who is complaining of pain, stiffness, fatigue, and headaches. Result Alkaline phosphatase= significantly increased Gamma glutamyltransferase= normal

D. Osteitis deformans

What compound chelates iron and is the immediate precursor of heme formation?

D. Protoporphyrin IX

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D. Send the specimen to a lab that offers other techniques to separate more effectively the HDL cholesterol.

Which of the following factors will NOT adversely affect the accurate quantification of bilirubin in serum?

D. Specimen refrigeration

Which compounds originally condense to form aminolevulinic acid?

D. Succinyl coenzyme A and glycine

Enzymes that catalyze the transfer of groups between compounds are classified as belonging to which enzyme class?

D. Transferases

A patients total cholesterol/HDL cholesterol ration is 10.0. What level risk for coronary heart disease does this result indicate?

D. Twice the average risk

A healthy, active 10 year old boy with no prior history of illness comes to the lab after school for a routine chemistry screen in order to meet requirements for summer camp. The serum looks cloudy. Specimen Blood Glucose= 135 Total cholesterol= 195 What is the most probable explanation?

D. Was most likely not fasting when the specimen was drawn

Which of the following is a qualitative screening test for porphobilinogen that may be performed to aid in the diagnosis of the porphyrias?

D. Watson-Schwartz test