ASCP Clinical Chemistry 1 — Questions and Answers
Question 1: Which enzyme is most specific for myocardial infarction when elevated?
- AST
- LDH
- Troponin I (Correct answer)
- ALT
Correct answer: Troponin I
Cardiac troponin I is highly specific to cardiac muscle and is the gold standard biomarker for myocardial infarction.
Question 2: A fasting glucose of 135 mg/dL on two separate occasions is diagnostic of:
- Normal glucose
- Impaired fasting glucose
- Diabetes mellitus (Correct answer)
- Hypoglycemia
Correct answer: Diabetes mellitus
A fasting plasma glucose ≥126 mg/dL confirmed on two occasions meets ADA criteria for diabetes mellitus diagnosis.
Question 3: Which lipoprotein is considered 'good cholesterol' due to its role in reverse cholesterol transport?
- LDL
- VLDL
- HDL (Correct answer)
- IDL
Correct answer: HDL
HDL transports cholesterol from peripheral tissues back to the liver for excretion, reducing cardiovascular risk.
Question 4: The normal anion gap range is approximately:
- 1–5 mEq/L
- 8–12 mEq/L (Correct answer)
- 20–25 mEq/L
- 30–40 mEq/L
Correct answer: 8–12 mEq/L
The normal anion gap (Na − [Cl + HCO3]) is 8–12 mEq/L, representing unmeasured anions like albumin and phosphate.
Question 5: Hemoglobin A1c reflects average blood glucose over approximately what time period?
- 1–2 weeks
- 30 days
- 2–3 months (Correct answer)
- 6 months
Correct answer: 2–3 months
HbA1c reflects glycation of hemoglobin over the 2–3 month lifespan of red blood cells.
Question 6: Elevated serum amylase and lipase are most indicative of:
- Liver cirrhosis
- Acute pancreatitis (Correct answer)
- Renal failure
- Myocardial infarction
Correct answer: Acute pancreatitis
Both amylase and lipase are released from damaged pancreatic acinar cells during acute pancreatitis.
ASCP Clinical Chemistry 1
Which enzyme is most specific for myocardial infarction when elevated?