Biosynthesis of Nucleic Acids

The first enzyme which regulates pyrimidine de novo synthesis is

• Carbamoyl phosphate

• OMP decarboxylase

• Carbamoyl phosphate synthetase II

• Aspartate transcarbamoylase

Thymidylate synthase is involved in producing RNA nucleotide

• True

• False

In pyrimidine salvage pathway, nucleoside kinase catalyses production of nucleotides

• True

• False

De novo synthesis of purines differs from pyrimidine by the involvement of

• Glutamate

• Aspartate

• Glycine

In the presence of aspartate, IMP will favor production of

• OMP

• AMP

• GMP

• UMP

Lack of HGPRT may increase level of purine bases

• True

• False

In pyrimidine degradation, thymine--> dihydrothymine --> N-carbamoyl-B-alanine --> X --> Acetyl-coA. What is X?

• B-alanine

• B-aminoisobutyrate

• Ammonia

• None of the options

Breakdown of hypoxanthine and guanine is similarly catalyzed by an enzyme called