【单选题】, Which of the following statement is wrong regarding the de novo synthesis of purine nucleotides:
A.
IMP is first synthesized, and then branched into synthesis of AMP and GMP.
B.
Substrate ribose-5-phosphate in the salvage pathway of nucleotide synthesis is provided by 5-phosphoribosyl-1-pyrophosphate.
C.
Both of the synthesis of 5-phosphoribosyl-1-pyrophosphate (PRPP) and 5-phosphoribosyl-1 amine (PRA) are regulatory points in the de novo synthesis of purine nucleotides.
D.
The synthesis of 5-phosphoribosyl-1 amine (PRA) is the committed step in the de novo synthesis of purine nucleotides.
E.
It is the least important pathway for purine nucleotide synthesis.
【单选题】听力原文: Police in London have warned people to remain cautious following the bomb attacks during Thursday morning's rush hour on the city's transport system. The attacks are believed to have killed at l...