Question

Which of the pathways for nucleotide biosynthesis builds the base ring on a PRPP molecule?

A) purine B) pyrimidine C) both purine and pyrimidine

Answer 1

A) purine

Step-by-step explanation:

There are two ways for the synthesis of purines and pyrimidines:

• de novo synthesis-from basic simple units

• "recycling" synthesis-reuse of metabolites

Purines are synthesized directly on ribose sugar, in segments.

Pyrimidines are attached to the ribose after the synthesis of the base.

5-Phosphoribosyl-1-pyrophosphate (PRPP). is used for the synthesis of purine (ribose 5-phosphate reacts with ATP to form ribonucleotide).