Question

Four molecules required for purine synthesis (PRPP --> IMP)

A. ATP, GTP, UTP, CTP
B. PRPP, Glycine, Aspartate, Glutamine
C. IMP, AMP, GMP, UMP
D. Ribose, Adenine, Guanine, Cytosine

Answer 1

The four molecules required for purine synthesis from B. PRPP to IMP are PRPP, Glycine, Aspartate, and Glutamine, which provide various atoms to construct the purine ring.

Step-by-step explanation:

The question is asking which four molecules are required for purine synthesis in the pathway from PRPP (Phosphoribosyl pyrophosphate) to IMP (Inosine monophosphate). The correct answer to this query is: B. PRPP, Glycine, Aspartate, and Glutamine.

De novo synthesis of purine nucleotides involves the construction of the purine ring along with the nucleotide, attached to the ribose sugar provided from the HMP (Hexose Monophosphate Pathway). The precursors for the purine ring come from various sources:

• N-1 is contributed by the nitrogen of aspartate.
• N-3 and N-9 come from the amide nitrogen of glutamine.
• C-6 is derived from respiratory carbon dioxide.
• C-2 and C-8 come from formate.
• C-4, C-5, and N-7 all are derived from glycine.