Medical Laboratory Technician Exam FREE Medical Laboratory Technician Clinical Chemistry Procedures Questions and Answers 2 — Questions and Answers
Question 1: Which enzyme is most commonly measured to assess acute pancreatitis in clinical chemistry?
- Lipase (Correct answer)
- Alkaline phosphatase
- Creatine kinase
- Lactate dehydrogenase
Correct answer: Lipase
Lipase is the preferred enzyme marker for acute pancreatitis due to its high sensitivity and specificity for pancreatic tissue damage.
Question 2: What is the principle behind the Jaffe reaction used in clinical chemistry laboratories?
- Creatinine reacts with alkaline picrate to form a red-orange complex (Correct answer)
- Glucose is oxidized by glucose oxidase
- Urea is hydrolyzed by urease
- Bilirubin reacts with diazo reagent
Correct answer: Creatinine reacts with alkaline picrate to form a red-orange complex
The Jaffe reaction measures creatinine by forming a red-orange chromogen when creatinine reacts with picric acid in an alkaline solution.
Question 3: In the enzymatic method for glucose measurement, what does hexokinase catalyze?
- Phosphorylation of glucose to glucose-6-phosphate (Correct answer)
- Oxidation of glucose to gluconic acid
- Reduction of NAD+ to NADH directly
- Conversion of glucose to fructose
Correct answer: Phosphorylation of glucose to glucose-6-phosphate
Hexokinase catalyzes the phosphorylation of glucose using ATP to produce glucose-6-phosphate, which is then further reacted to generate a measurable signal.
Question 4: Which specimen type is preferred for measuring ionized calcium in clinical chemistry?
- Anaerobic whole blood collected in heparin (Correct answer)
- Serum separated after 2 hours
- EDTA plasma
- Citrated plasma
Correct answer: Anaerobic whole blood collected in heparin
Anaerobic heparinized whole blood is preferred because exposure to air increases pH, which shifts calcium binding to albumin and falsely lowers ionized calcium.
Question 5: What does an elevated serum AST-to-ALT ratio greater than 2:1 typically suggest?
- Alcoholic liver disease (Correct answer)
- Viral hepatitis
- Obstructive jaundice
- Hemolytic anemia
Correct answer: Alcoholic liver disease
An AST-to-ALT ratio greater than 2:1 is a classic pattern associated with alcoholic liver disease due to alcohol-induced mitochondrial damage releasing more AST.
Question 6: Which electrolyte measurement is most affected by hemolysis of a blood specimen?
- Potassium (Correct answer)
- Sodium
- Chloride
- Bicarbonate
Correct answer: Potassium
Potassium is present in much higher concentrations inside red blood cells than in plasma, so hemolysis causes a significant falsely elevated potassium result.
Medical Laboratory Technician Exam FREE Medical Laboratory Technician Clinical Chemistry Procedures Questions and Answers 2
Which enzyme is most commonly measured to assess acute pancreatitis in clinical chemistry?