All of the Following Are True Concerning the Regulation of the Purine

Multiple Choice

All of the following are true concerning the regulation of the purine biosynthetic pathway EXCEPT:

A) ATP is the energy source for AMP synthesis.
B) ADP and GDP are feedback inhibitors of ribose-5-phosphate pyrophosphokinase.
C) "A" and "C" nucleotides allosterically inhibit glutamine phosphoribosyl pyrophosphate amidotransferase (Gln:PRPP amidotransferase) .
D) The rate of IMP formation is dependent on the levels of the adenine and guanine nucleotides produced.
E) PRPP competitively inhibits the enzyme Gln:PRPP amidotransferase.