In the de novo synthesis of purines,
the carbon atoms in the purine bases are
derived from
A.
glucose, aspartate, glycine
B.
glutamine, erythrose-4-P, tetrahydrofolate
C.
CO2, glycine, formate
(or N5, N10-methylene
tetrahydrofolate)
D.
serine, glycine, glycolytic intermediates