Which of the following is the precursor of the indicated carbon atom in a pyrimidine ring?
A) aspartate
B) glycine
C) carbamoyl phosphate
D) orotate

Question

Which of the following is the precursor of the indicated carbon atom in a pyrimidine ring? 
A) aspartate 
B) glycine 
C) carbamoyl phosphate 
D) orotate

Quizplus · Accepted Answer

The precursor of the indicated carbon atom in a pyrimidine ring is carbamoyl phosphate. Carbamoyl phosphate is synthesized from ammonia and carbon dioxide in the first step of the pyrimidine biosynthetic pathway, and it is ultimately converted into orotic acid, which is the precursor of pyrimidine nucleotides. Aspartate and glycine are involved in the biosynthesis of purine nucleotides, while orotate is derived from carbamoyl phosphate, but it is not the precursor of a specific carbon atom in the pyrimidine ring.

Which of the Following Is the Precursor of the Indicated