DNA basics Flashcards
What is required to make purines
- Glycine
- Glutamine
- Aspartate
- Tetrahydrofolate
- CO2
What provides the carbons for purine synthesis
- Glycine
- Tetrahydrofolate
- CO2
What provides nitrogens for purine synthesis
- glutamine
- aspartate
What is required for pyrimidine synthesis
- Aspartate
- Carbamoyl phosphate: CO2, glutamine, ATP
pathway for carbamoyl phosphate synthetase II (CPS-2)?
location?
-source of nitrogen
- Pyrimadine synthesis
- cytosol
- Glutamine
Orotic aciduria is a deficiency in what
UMP synthase
Describe Orotic aciduria
- autosomal recessive
- increase in orotic acid in urine
- megaloblastic anemia that cannot be corrected with B12 or folic acid
- does NOT cause hyperammonemia
Treatment of orotic aciduria
-uridine supplementation
What if i see increase orotic acid in urine and increase in ammonia? what the deficiency
ornithine transcarbamylase deficiency
clinical features of HGPRT deficiency
- boys
- Gout
- Intellectual disability
- aggressive behavior
- Self mutilation: lip biting
- Movement disorders: dystonia
What is the rate-limiting enzyme in purine synthesis?
Glutamine PRPP amidotransferase
What is the rate-limiting enzyme in pyrimidine synthesis?
-CPS-2
sources of carbon for pyrimidines
- Aspartate
- CO2
What medication inhibits ribonucleotide reductase?
Hydroxyurea
What medication inhibits dihydrofolate reductase?
- Trimethoprim
- Methotrexate
