1. In non competitive enzyme activity inhibition, inhibitor
(A) Increases Km
(B) Decreases Km
(C) Does not affect Km
(D) Increases Km
Answer:(C) Does not affect Km
2. An enzyme catalyzing oxidoreduction, using oxygen as hydrogen acceptor is
(A) Cytochrome oxidase
(B) Lactate dehydrogenase
(C) Malate dehydrogenase
(D) Succinate dehydrogenase
Answer:(A) Cytochrome oxidase
3. The enzyme using some other substance, not oxygen as hydrogen acceptor is
(A) Tyrosinase
(B) Succinate dehydrogenase
(C) Uricase
(D) Cytochrome oxidase
Answer: (B) Succinate dehydrogenase
4. An enzyme which uses hydrogen acceptor as substrate is
(A) Xanthine oxidase
(B) Aldehyde oxidase
(C) Catalase
(D) Tryptophan oxygenase
Answer:(C) Catalase
5. Enzyme involved in joining together two substrates is
(A) Glutamine synthetase
(B) Aldolase
(C) Guanine deaminase
(D) Arginase
Answer:(A) Glutamine synthetase
6. The pH optima of most of the enzymes is
(A) Between 2 and 4
(B) Between 5 and 9
(C) Between 8 and 12
(D) Above 12
Answer:(B) Between 5 and 9
7. Coenzymes are
(A) Heat stable, dialyzable, non protein organic molecules
(B) Soluble, colloidal, protein molecules
(C) Structural analogue of enzymes
(D) Different forms of enzymes
Answer:(A) Heat stable, dialyzable, non protein organic molecules
8. An example of hydrogen transferring coenzyme is
(A) CoA
(B) NAD+
(C) Biotin
(D) TPP
Answer:(B) NAD+
9. An example of group transferring coenzyme is
(A) NAD+
(B) NADP+
(C) FAD
(D) CoA
Answer:(D) CoA
10. Cocarboxylase is
A) Thiamine pyrophosphate
(B) Pyridoxal phosphate
(C) Biotin
(D) CoA
Answer:(C) Biotin
11. A coenzyme containing non aromatic hetero ring is
(A) ATP
(B) NAD
(C) FMN
(D) Biotin
Answer:(D) Biotin
12. A coenzyme containing aromatic hetero ring is
(A) TPP
(B) Lipoic acid
(C) Coenzyme Q
(D) Biotin
Answer:(A) TPP
13. Isoenzymes are
(A) Chemically, immunologically and electrophoretically different forms of an enzyme
(B) Different forms of an enzyme similar in all properties
(C) Catalysing different reactions
(D) Having the same quaternary structures like the enzymes
Answer:(A) Chemically, immunologically and electrophoretically different forms of an enzym
14. Isoenzymes can be characterized by
(A) Proteins lacking enzymatic activity that are necessary for the activation of enzymes
(B) Proteolytic enzymes activated by hydrolysis
(C) Enzymes with identical primary structure
(D) Similar enzymes that catalyse different reactions
Answer:(B) Proteolytic enzymes activated by hydrolysis
15. The isoenzymes of LDH
(A) Differ only in a single amino acid
(B) Differ in catalytic activity
(C) Exist in 5 forms depending on M and H monomer contents
(D) Occur as monomers
Answer:(C) Exist in 5 forms depending on M and H monomer contents
16. The normal value of CPK in serum varies between
(A) 4–60 IU/L
(B) 60–250 IU/L
(C) 4–17 IU/L
(D) > 350 IU/L
Answer:(A) 4–60 IU/L
17. Factors affecting enzyme activity:
(A) Concentration
(B) pH
(C) Temperature
(D) All of these
Answer:(D) All of these
18. The normal serum GOT activity ranges from
(A) 3.0–15.0 IU/L
(B) 4.0–17.0 IU/L
(C) 4.0–60.0 IU/L
(D) 0.9–4.0 IU/L
Answer:(B) 4.0–17.0 IU/L
19. The normal GPT activity ranges from
(A) 60.0–250.0 IU/L
(B) 4.0–17.0 IU/L
(C) 3.0–15.0 IU/L
(D) 0.1–14.0 IU/L
Answer:(C) 3.0–15.0 IU/L
20. The normal serum acid phosphatase activity ranges from
(A) 5.0–13.0 KA units/100 ml
(B) 1.0–5.0 KA units/100 ml
(C) 13.0–18.0 KA units/100 ml
(D) 0.2–0.8 KA units/100 ml
Answer:(B) 1.0–5.0 KA units/100 ml
21. The normal serum alkaline phosphatase activity ranges from
(A) 1.0–5.0 KA units/100 ml
(B) 5.0–13.0 KA units/100 ml
(C) 0.8–2.3 KA units/100 ml
(D) 13.0–21.0 KA units/100 ml
Answer:(B) 5.0–13.0 KA units/100 ml
22. In early stages of myocardial ischemia the most sensitive indicator is the measurement of the activity of
(A) CPK
(B) SGPT
(C) SGOT
(D) LDH
Answer:(A) CPK
23. Serum acid phosphatase level increases in
(A) Metastatic carcinoma of prostate
(B) Myocardial infarction
(C) Wilson’s disease
(D) Liver diseases
Answer:(A) Metastatic carcinoma of prostate
24. Serum alkaline phosphatase level increases in
(A) Hypothyroidism
(B) Carcinoma of prostate
(C) Hyperparathyroidism
(D) Myocardial ischemia
Answer:(C) Hyperparathyroidism
25. Serum lipase level increases in
(A) Paget’s disease
(B) Gaucher’s disease
(C) Acute pancreatitis
(D) Diabetes mellitus
Answer:(C) Acute pancreatitis
26. Serum ferroxidase level decreases in
(A) Gaucher’s disease
(B) Cirrhosis of liver
(C) Acute pancreatitis
(D) Wilson’s disease
Answer:(D) Wilson’s disease
27. The isoenzymes LDH5 is elevated in
(A) Myocardial infarction
(B) Peptic ulcer
(C) Liver disease
(D) Infectious diseases
Answer:(C) Liver disease
28. On the third day of onset of acute myocardial infarction the enzyme elevated is
(A) Serum AST
(B) Serum CK
(C) Serum LDH
(D) Serum ALT
Answer:(C) Serum LDH
29. LDH1 and LDH2 are elevated in
(A) Myocardial infarction
(B) Liver disease
(C) Kidney disease
(D) Brain disease
Answer:(A) Myocardial infarction
30. The CK isoenzymes present in cardiac muscle is
(A) BB and MB
(B) MM and MB
(C) BB only
(D) MB only
Answer:(B) MM and MB
