During de novo pyrimidine synthesis, the pyrimidine ring is assembled and then joined to phosphoribosyl pyrophosphate (PRPP), forming orotidine monophosphate. Orotidine monophosphate is next converted to uridylate, or UMP. UMP can then be converted to another pyrimidine ribonucleotide, CTP. Identify the source of each atom in the pyrimidine ring.

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 9 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of tthe table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 9 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.