Question

Which of the following reaction is not catalyzed by 5^I – nucleotidase?

(a) Adenosine monophosphate to adenosine

(b) Inosine 5^I – phosphate to inosine

(c) Guanosine monophosphate to guanine

(d) Creatine phosphate to creatine

This question was addressed to me in an online interview.

This interesting question is from Clinical Significance of 5′ topic in chapter Clinical Enzymology of Enzyme Technology

Answer 1

Correct choice is (d) Creatine phosphate to creatine

Best explanation: Creatine phosphate to creatine is catalyzed by creatine kinase which donates the phosphate group to ADP forming ATP. Purine nucleotides are degraded by a pathway in which they lose the phosphate group by action of 5^I – nucleotidase in the following ways:

• Adenosine monophosphate to adenosine.

• Inosine 5^I – phosphate to inosine.

• Guanosine monophosphate to guanine.

These 3 pathways final product is uric acid.