This section contains 65 multiple-choice questions (MCQs) covering various aspects of clinical enzymology. These questions are designed to test your understanding of enzyme function, clinical applications, and diagnostic techniques. Each question is carefully crafted to assess your knowledge and critical thinking skills in this important field of medical science.
- Which of the following substrates are used in ACE measurement?
- 1. Benzoylglycine
- 2. Hippuryl-histidyl-leucine
- 3. Furylacrylic acid
- 4. Benzoyl-glycyl-glycine
- A. only 1 and 3 are correct
- B. only 2 and 4 are correct
- C. only 1, 2, and 3 are correct
- D. 1, 2, 3, and 4 are correct ✅
- An increased ACE activity is seen in:
- A. Sarcoidosis ✅
- B. Toxic lung damage
- C. Endothelial dysfunction
- D. Hypothyroidism
- Which of the following can reduce/inhibit ACE activity?
- 1. EDTA
- 2. Captopril
- 3. Enalapril
- 4. Zinc chelators
- A. only 1 and 3 are correct
- B. only 2 and 4 are correct
- C. only 1, 2, and 3 are correct
- D. 1, 2, 3, and 4 are correct ✅
- What is the EC number of AST?
- A. 2.6.1.1 ✅
- B. 2.6.1.2
- C. 3.1.1.7
- D. 3.1.1.6
- De Ritis ratio for differentiation between mild liver damage and severe liver disease is:
- A. GGT/AST
- B. AST/ALT ✅
- C. AST/LD
- D. LD/GGT
- This ratio is used as an indicator of cholestasis and alcoholic liver damage.
- A. GGT/AST ✅
- B. AST/ALT
- C. AST/LD
- D. LD/GGT
- Which of the following methods are used for cholinesterase determination?
- 1. Inhibition test with dibucaine
- 2. Determination of fluoride number
- 3. Ro 2-0683
- 4. Photometric rate assay
- A. only 1 and 3 are correct
- B. only 2 and 4 are correct
- C. only 1, 2, and 3 are correct
- D. 1, 2, 3, and 4 are correct ✅
- Which of the following chemicals is/are associated with a decrease in cholinesterase activity?
- A. Muscle relaxants
- B. Organophosphate esters
- C. Carbamate esters
- D. all of these ✅
- Determination of acylcholine acylhydrolase for evaluation of liver function is usually performed using what substrate?
- A. Glycine
- B. Phosphate
- C. Choline ✅
- D. Nitroanilide
- CK catalyzes the reversible transfer of the phosphate group from creatine phosphate to Mg-ADP. The resulting Mg-ATP is determined in a combined optical test using what as coenzyme?
- A. Glucose-6-phosphate dehydrogenase
- B. Oxidase
- C. Hexokinase ✅
- D. Adenylate kinase
- A CK-MB fraction of more than 6% of the total CK activity is regarded as diagnostic for:
- A. Myocardial infarction ✅
- B. Muscular dystrophy
- C. Skeletal muscle damage
- D. Secondary myopathies
- Which of the following findings can indicate the presence of macro CK?
- A. Elevated total CK with a CK-MB fraction >25% ✅
- B. Elevated total CK with a CK-BB fraction >6%
- C. Elevated total CK with a CK-MM fraction >5%
- D. Elevated total CK with a CK-MiMi fraction >10%
- The variant of CK with higher molecular mass formed when CK is bound by specific immunoglobulins:
- A. Macro CK type 1 ✅
- B. Macro CK type 2
- C. CK-MiMi
- D. CK-MT or CKMito
- Which enzyme is specific for liver and bile duct and an increase of this enzyme is considered as one of the most sensitive indicators of hepatobiliary disease?
- A. Cholinesterase
- B. GGT ✅
- C. CK
- D. AST
- Differentiation between jaundice of hepatic or cholestatic origin can be based on ALT activity and the:
- A. AST/ALT ratio
- B. GGT/AST ratio
- C. GGT/ALT ratio ✅
- D. ALT/ALP ratio
- Which enzyme is used with aminotransferases and mean cellular volume of erythrocytes as indicators of excessive alcohol consumption?
- A. Cholinesterase
- B. GGT ✅
- C. GLD
- D. AST
- Which of the following anticoagulants may lead to falsely low GGT activity?
- 1. Citrate
- 2. Oxalate
- 3. Fluoride
- 4. Heparin
- A. only 1 and 3 are correct
- B. only 2 and 4 are correct
- C. only 1, 2, and 3 are correct
- D. 1, 2, 3, and 4 are correct ✅
- This is the only enzyme which cleaves a significant amount of glutathione.
- A. Cholinesterase
- B. GGT ✅
- C. GLD
- D. AST
- A (ALT + AST)/GLD ratio of <20 is seen in:
- 1. Obstructive jaundice
- 2. Biliary cirrhosis
- 3. Metastatic liver disease
- 4. Acute hypoxic liver damage
- A. only 1 and 3 are correct
- B. only 2 and 4 are correct
- C. only 1, 2, and 3 are correct
- D. 1, 2, 3, and 4 are correct ✅
- A (ALT + AST)/GLD ratio of >50 is seen in:
- 1. Acute episodes of chronic liver diseases
- 2. Acute viral hepatitis
- 3. Cholestatic hepatic diseases
- 4. Acute alcoholic hepatitis
- A. only 1 and 3 are correct
- B. only 2 and 4 are correct ✅
- C. only 1, 2, and 3 are correct
- D. 1, 2, 3, and 4 are correct
