Question

Suppose that a strain of bacteria lacks a key biochemical used in purine synthesis. Complete all the statements about purine synthesis in these bacteria.

1) _________(phosphoribosyl amine / glycinamide ribonucleotide / formylglycinamide ribonucleotide) will accumulate in bacteria that lack glycine. The atoms of glycine form part of both ring structures.

2) The intermediate _________(formylglycinamide ribonucleotide / glycinamide ribonucleotide / N10-formyltetrahydrofolate) will build up in the absence of tetrahydrofolate. N10‑Formyltetrahydrofolate donates _________(a phosphate group / an amino group / a formyl group) to the substrate.

3) _________(formylglycinamide ribonucleotide / glycinamide ribonucleotide / formylglycinamidine ribonucleotide) will accumulate in the absence of glutamine. Glutamine donates _________(an amino group / a phosphate group / a formyl group).

4) The intermediate _________(fumarate / carbamoyl phosphate / carboxyaminoimidazole ribonucleotide / carbamoyl aspartate) will accumulate when aspartate is lacking. Aspartate donates _________(a phosphate group / a formyl group / an amino group).

Answer 1

1. Phosphoribosyl amine

2. glycinamide ribonucleotide (GAR), a formyl group

3. Formylglycinamide ribonucleotide (FGAR), an amino group

4. Carboxyaminoimidazole ribonucleotide (CAIR), an amino group.

Step-by-step explanation:

1. Phosphoribosyl amine will accumulate in bacteria that lack glycine.

2. The intermediate glycinamide ribonucleotide (GAR) will build up in the absence of tetrahydrofolate.

N10‑Formyltetrahydrofolate donates a formyl group to the substrate

3. Formylglycinamide ribonucleotide (FGAR) will accumulate in the absence of glutamine.

Glutamine donates an amino group

4. The intermediate carboxyaminoimidazole ribonucleotide (CAIR) will accumulate when aspartate is lacking.

Aspartate donates an amino group.