Clinical Enzymology & Isoenzymes MCQ Quiz | Enzymology

Welcome to the Clinical Enzymology & Isoenzymes quiz, specifically designed for MBBS students. This module is crucial for understanding how enzyme levels in body fluids can diagnose and monitor diseases. This quiz features 25 multiple-choice questions covering key topics such as myocardial infarction markers (CK-MB, LDH), liver function tests (ALT, AST), pancreatic enzymes (Amylase, Lipase), and the significance of various isoenzymes. Each question will test your ability to apply biochemical knowledge to clinical scenarios. After completing the quiz, you can submit your answers to see your score and review the correct responses. For your revision, a ‘Download PDF’ option is available, providing all questions with their correct answers. Good luck!

1. A 55-year-old male presents with severe chest pain. Which of the following isoenzymes is most specific for diagnosing an acute myocardial infarction (MI) within 4-6 hours of onset?

2. In viral hepatitis, which enzyme is typically elevated more significantly than others, making it a more specific marker for hepatocellular damage?

3. A patient with acute pancreatitis would most likely show a marked elevation in which two serum enzymes?

4. An elevated serum Alkaline Phosphatase (ALP) level is commonly associated with diseases of the:

5. Isoenzymes are best defined as:

6. An “LDH flip,” where LDH-1 > LDH-2, is a characteristic finding in:

7. Which enzyme is a sensitive indicator of alcohol-induced liver disease?

8. A De Ritis ratio (AST/ALT) greater than 2:1 is highly suggestive of:

9. Which of the following is considered a non-functional plasma enzyme?

10. In acute pancreatitis, serum lipase is considered a more specific marker than serum amylase because:

11. A deficiency in which enzyme leads to drug-induced hemolytic anemia, especially after administration of certain antimalarials or sulfonamides?

12. The most common laboratory method used to separate and quantify isoenzymes like LDH and CK is:

13. Prostatic carcinoma that has metastasized is often associated with a high serum level of:

14. The CK-MB isoenzyme begins to rise in the serum how long after the onset of an acute MI?

15. The predominant LDH isoenzyme in the liver and skeletal muscle is:

16. Physiological (non-pathological) elevation of serum ALP is seen in:

17. Organophosphate poisoning is characterized by the inhibition of which enzyme?

18. While CK-MB is a good marker for MI, which of the following is now considered the “gold standard” due to its higher specificity and sensitivity?

19. The international unit (IU/L) of enzyme activity is defined as the amount of enzyme that catalyzes the conversion of:

20. Macro-CK is a form of Creatine Kinase that is:

21. In obstructive liver disease (cholestasis), which enzyme typically shows the most pronounced elevation?

22. CK-BB isoenzyme is predominantly found in which tissue?

23. An isolated rise in serum GGT, with normal ALP and other liver enzymes, is often linked to:

24. What is the significance of measuring the half-life of a plasma enzyme?

25. A patient with Duchenne muscular dystrophy will have a markedly elevated level of which enzyme?