Question

Which of the following statements is TRUE?

A) PRPP is an effective feedback inhibitor of nucleotide synthesis.
B) GTP serves as the energy input for AMP synthesis from IMP.
C) Oxidation of ribosyl moieties to produce deoxynucleotides occurs at the diphosphate level.
D) Thymidylate synthase methylates dUTP to produce dTTP.
E) All of the above are true.

Answer 1

Answer: B (GTP serves as the energy input for AMP synthesis from IMP)

Step-by-step explanation:

In the de novo synthesis of purine nucleotide, IMP represents a branch point for purine biosynthesis. IMP can be converted to either AMP or GMP.

The formation of AMP from IMP requires GTP; similarly formation of GMP requires ATP. The conversion of IMP to either AMP or GMP is highly regulated – AMP and GMP inhibits their own formation by feedback inhibition of adenlyosuccinate synthetase and IMP dehydrogenase.