Which enzyme acts as a hydrolase and is used as a marker for liver disease?

• A. LAP
• B. Ornithine Carbamoyl Transferase
• C. Alkaline Phosphatase
• D. ALT

Answer: (A)

Enzymes that act as hydrolases catalyze the breaking of chemical bonds by adding water, such as removing phosphate groups from molecules. Alkaline phosphatase is a classic hydrolase that removes phosphate groups from many substrates. In clinical practice, its serum activity rises in liver and biliary diseases, especially conditions causing cholestasis, so it’s used as a marker of liver disease.

ALT, by contrast, is a transaminase, transferring amino groups rather than hydrolyzing bonds, so it reflects hepatocellular injury rather than cholestasis. Ornithine carbamoyl transferase is a transferase involved in the urea cycle, not a hydrolase or a primary liver disease marker. LAP, or leukocyte alkaline phosphatase, is a phosphatase found in white blood cells and is used mainly in hematology to assess leukocyte function, not as a standard liver disease marker.

So the enzyme that is a hydrolase and used as a marker for liver disease is alkaline phosphatase.