Nucleotides Flashcards
Nucleotide
component of DNA and RNA and coenzymes
carriers of activated intermediates
Purines
Adenine and Guanine
Pyrimidines
Cytosine, Thymine, Uracil
Nucleoside
Nitrogenous Base + sugar
Nucleotide
Nucleoside + 1-3 phosphate group
Where does Ribose 5-P come from for purine synthesis?
HMP shunt
PRPP Synthetase
catalyzes formation of PRPP in purine synthesis
attaches PRPP to C1
Activator of PRPP Synthetase
Inorganic phosphate
Inhibitor of PRPP Synthetase
purine ribonucleotides
PRPP Amidotransferase
rate limiting step of purine synthesis
PRPP Amidotransferase Activators
PRPP (substrate)
PRPP Amidotransferase Inhibitors
purine nucleotides (end products)
Methotrexate
folic acid analog; anti-tumor drug
inhibits dihydrofolate reductase- inhibits nucleotide synthesis and rapidly dividing cells
Sulfonamides
inhibit bacterial production of folic acid
Antibiotic
CPS II
rate limiting step of pyrimidine synthesis
Activator of CPS II
PRPP
Inhibitor of CPS II
UTP (end product)
AA in nucleotides of pyrimidines
glutamine and aspartate
Ribonucleotide Reductase
converts ribonucleotides to deoxyribonucleotides
Hydroxyurea
anti-tumor drug that inhibits ribonucleotide reductase
Thymidylate Synthase
converts dUMP to dTMP
Inhibitors of thymidylate synthase
5-fluorouracil
Adenosine Deaminase Deficiency
one cause of severe combined immunodeficiency disease (SCID)
Xanthine Oxidase
produces uric acid from xanthine
Gout
hyperuricemia- high levels of uric acid in blood
accumulates uric acid crystals in joints
Causes of Gout
underexcretion of uric acid because of
poor kidney function, acid base imbalance, certain drugs
overproduction of uric acid
Lesch Nyhan Syndrome
deficiency of purine salvage pathway from defect of HGPRT
extreme hyperuricemia
