Glutamine phosphoribosyl pyrophosphate amidotransferase catalyzes step 2 in the biosynthesis of purines.Which of the following regarding the regulation of this enzyme is correct?
A)It is accelerated by an input of ATP or GTP.
B)It is sensitive to activation by azaserine.
C)It is accelerated by an input of AMP or GMP.
D)The G series of nucleotides as well as the adenine nucleotides act as competitive inhibitors.

Question

Quizplus · Accepted Answer

The enzyme glutamine phosphoribosyl pyrophosphate amidotransferase is regulated through feedback inhibition by the end products of its pathway, which include both the G series of nucleotides (guanine nucleotides) and the adenine nucleotides. These nucleotides act as competitive inhibitors, binding to the enzyme and preventing it from catalyzing the reaction that leads to their own synthesis, thereby maintaining a balance in the cell's nucleotide pool.

Glutamine Phosphoribosyl Pyrophosphate Amidotransferase Catalyzes Step 2 in the Biosynthesis