Lecture 3 Flashcards
what does PRPP stand for?
5-Phosphoribosyl pyrophosphate
process of purine synthesis (ATP)
ribose-5-phosphate + ATP —-> PRPP —-> phosphoribosyl beta 1 amine —-> (9 steps) —-> IMP —-> adenylosuccinate —-> AMP + ATP —-> ADP + Pi —-> ATP
process of purine synthesis (GTP)
ribose-5-phosphate + ATP —-> PRPP —-> phosphoribosyl beta 1 amine —-> (9 steps) —-> IMP —-> XMP + ATP —-> GMP —-> GDP —-> GTP
what are the enzymes involved in ATP purine synthesis
adenylate kinase and ATP synthase
what are the enzymes involved in GTP purine synthesis
guanylate kinase and non-specific nucleoside diphosphate kinase
allosteric regulators in ATP synthesis
ADP, AMP, ATP regulate PRPP to to phosphoribosyl beta amine
ADP regulates ribose 5 phosphate to PRPP
allosteric regulators in GTP synthesis
GMP, GDP, GTP regulate PRPP to phosphoribosyl beta 1 amine
GDP regulates PRPP to phosphoribosyl beta 1 amine
pyrimidine synthesis
orotate + PRPP —-> OMP —-> UMP + ATP —-> UDP + ATP —-> UTP + ATP —-> CTP
orotate synthesis (involved in the synthesis of UTP and CTP
HCO3- + Glutamine + H2O + 2 ATP —-> carbamoyl phosphate + aspartate —-> orotate
competitive inhibition in ATP synthesis
AMP inhibits IMP —-> Adenylosuccinate
competitive inhibition in GTP synthesis
GMP inhibits IMP —-> XMP
allosteric inhibition in pyrimidine synthesis
UDP and UTP inhibit glutamine to carbamoyl phosphate
allosteric activation in pyrimidine synthesis
PRPP activates glutamine —-> carnbamoyl phosphate
ribonucleotide reductase makes dNDPs
- reduces NDP to dNDP
what is meant by “balancing” nucleotides
relative amounts of the nucleotides (wouldn’t have equal amounts of everything, its referring to relative amounts of the nucleotides)
