Exam 25: Nucleotide Biosynthesis

Which of the following is the methyl donor in the synthesis of dTMP from dUMP?

In the de novo synthesis of DNA and RNA,

In de novo synthesis, the pyrimidine ring is assembled using

_______________ disease is caused by a genetic mutation resulting in the absence of hypoxanthine-guanine phosphoribosyl transferase.

Inosinate can be converted to

Scaffolds on which the ring systems in nucleotides are assembled are the amino acids glycine and _______________.

Tetrahydrofolate is generated from dihydrofolate by dihydrofolate reductase and uses the reductant

Why do purine-salvage pathways save the cell energy?

The two nucleotides that can serve as energy currency in certain biomolecular paths are ATP and _______________.

How is ATCase, a key enzyme in pyrimidine biosynthesis, inhibited?

Allopurinol is used to treat gout and is an inhibitor of the enzyme

What is the approximate rate change when the enzyme orotidylate decarboxylase decarboxylates orotidylate to form UMP?

The enzyme that catalyzes the generalized equation XDP + YTP $\rightarrow$ XTP + YDP is _________.

What vitamin supplement is taken during the first trimester of pregnancy to prevent the birth defect known as spina bifida?

What is/are the advantage or advantages of channeling intermediates by carbamoyl phosphate synthetase?

Dihydrofolate reductase is an excellent target for anticancer drugs because it is critical in the synthesis of _______________.

What is a general theme in purine ring synthesis, in terms of reaction logic and mechanism?

Given the function of nucleotides, would you expect their synthesis to be simple or complex and diverse?

What is the disadvantage of methotrexate as a therapeutic agent?

What enzyme carries out this reaction? UMP + ATP $\leftrightarrow$ UDP + ADP