M12337Each of the Following Statements Concerning De Novo Purine Ribonucleotide

M12337Each of the following statements concerning de novo purine ribonucleotide synthesis in humans is correct EXCEPT which one?

A) The first step (committed step) utilizes PRPP in the synthesis of phosphoribosylamine.
B) Glutamine is a direct source of carbon atoms for the purine ring.
C) Tetrahydrofolate coenzymes function in the introduction of two carbon atoms.
D) IMP is an intermediate in the synthesis of both AMP and GMP.
E) De novo synthesis of guanylic acid (GMP) involves 3 enzymes which utilize glutamine.