Serum enzymes

Question 1

1. The enzyme that demonstrates highest serum activity in
   Paget disease (osteitis deformans) and is also elevated in
   hepatobiliary disease is:
   a. alkaline phosphatase (ALP).
   b. creatine kinase (CK).
   c. amylase (AMY).
   d. α-glutamyltransferase (GGT)

Answer 1

a. alkaline phosphatase (ALP).

Question 2

2. Activity of which of the following isoenzymes of lactate
   dehydrogenase (LDH) is highest in the serum of individuals with seminoma of the testis?
   a. LDH-1
   b. LDH-2
   c. LDH-4
   d. LDH-5

Answer 2

a. LDH-1

Question 3

3. The serum enzyme that demonstrates an increase in activity 4 to 8 hours after an attack of acute pancreatitis, peaks
   at 24 hours, and then returns to normal within a week is:

a. AMY.
b. lipase (LPS).
c. ALP.
d. serum cholinesterase (CHE).

Answer 3

b. lipase (LPS).

Question 4

4. Which of the following enzymes catalyzes the reaction
   of glutamate and pyruvate to form 2-oxoglutarate and an
   amino acid?

a. ALP
b. Aspartate aminotransferase (AST)
c. Alanine aminotransferase (ALT)
d. CK

Answer 4

c. Alanine aminotransferase (ALT)

Question 5

5. In the laboratory measurement of ALP, a chromogenic
   assay forms the basis of almost all current methods used
   for ALP analysis. The substrate in this assay is:

a. acid phosphatase.
b. 4-nitrophenyl phosphate.
c. p-nitroaniline.
d. succinyldithiocholine

Answer 5

b. 4-nitrophenyl phosphate.

Question 6

6. Measurement of decreased activity of which of the following enzymes is used to determine possible insecticide
   poisoning?

a. CK
b. ALP
c. ALT
d. CHE

Answer 6

d. CHE

Question 7

7. Children have higher ALP activity than healthy adults
   because:

a. ALP leaks from osteoblasts during normal bone
growth.
b. developing hepatocytes produce excess ALP during
normal growth.
c. striated muscle contains the greatest activity of ALP,
and children are more energetic than adults with
concomitant release of excess ALP from muscle.
d. the presence of ALP in the pancreas is elevated
during childhood.

Answer 7

a. ALP leaks from osteoblasts during normal bone
growth.

Question 8

8. The isoenzyme of amylase that is synthesized by acinar cells
   of the pancreas and that remains elevated in most individuals for at least 1 week after the onset of pancreatitis is:
   a. S-AMY.
   b. macro-AMY.
   c. P-AMY.
   d. S-AMY + P-AMY

Answer 8

c. P-AMY.

Question 9

9. Which of the following enzymes demonstrates an increase
   in activity with progressive Duchenne muscular dystrophy, followed by a decrease as muscle mass decreases?

a. ALP
b. ALT
c. CHE
d. CK

Answer 9

d. CK

Question 10

10. The oxidoreductase that is increased significantly during
    megaloblastic anemia is:

a. LDH.
b. CK.
c. ALP.
d. acid phosphatase.

Answer 10

a. LDH.