CHE 4342 EXAM 5 QUESTIONS AND 100%
CORRECT ANSWERS!!
What pathways create the most nucleotides?
De Novo
What is the rate-limiting step of pyrimidine biosynthesis?
ATCase (Synthesizes Orotate)
Inhibited by CTP, Activated by ATP
What is used when synthesizing the pyrimidine ring?
Bicarb/CO2 (N3 and C2), aspartate, and glutamine
How much energy is needed to make one molecule of UMP from scratch?
4
2 from CPS2
2 from Oratate Phosphoribosyl Transferase
How is CTP formed from UTP?
CTP Synthetase (GLUTAMINE AMIDOTRANSFERASE)
Uses 1 ATP
How is pyrimidine synthesis controlled in animals?
CPS2
UDP and UTP feedback Inhibitors
PRPP and ATP activators
What is purine biosynthesis regulated by?
Amount of PRPP
How do we make AMP from IMP, and what is regulated?
, 1. Adenylosuccinate Synthetase (Asparatate, GTP)
2. Adenylosuccinate Lyase (-Fumarate)
Regulated by GMP formation
How do we make GMP from IMP and what is regulated?
1. IMP DH (NADH)
2. GMP Synthetase (GLUTAMINE AMIDOTRANSFERASE, Uses 2 ATP)
Regulated by AMP formation
What does mycophenolic acid do?
Inhibits IMP DH
What do azaserine and acivicin do?
Block glutamine amidotransferaseses
Control of Purine Biosynthesis
PRPP Synthetase: I'd by ADP and GDP
GPAT: I'd by A and G stuff
What reaction does ribonucleotide reductase (RNR) catalyze?
NDPs to dNDPS!!!!!!!!
What are the regions of RNR?
Specificity Site
Activity Site
Catalytic Site
USES TYR Radicals
What is the ultimate reductant in RNR?
NADPH
What acts as the ON and OFF switch in RNR?
ATP and dATP
CORRECT ANSWERS!!
What pathways create the most nucleotides?
De Novo
What is the rate-limiting step of pyrimidine biosynthesis?
ATCase (Synthesizes Orotate)
Inhibited by CTP, Activated by ATP
What is used when synthesizing the pyrimidine ring?
Bicarb/CO2 (N3 and C2), aspartate, and glutamine
How much energy is needed to make one molecule of UMP from scratch?
4
2 from CPS2
2 from Oratate Phosphoribosyl Transferase
How is CTP formed from UTP?
CTP Synthetase (GLUTAMINE AMIDOTRANSFERASE)
Uses 1 ATP
How is pyrimidine synthesis controlled in animals?
CPS2
UDP and UTP feedback Inhibitors
PRPP and ATP activators
What is purine biosynthesis regulated by?
Amount of PRPP
How do we make AMP from IMP, and what is regulated?
, 1. Adenylosuccinate Synthetase (Asparatate, GTP)
2. Adenylosuccinate Lyase (-Fumarate)
Regulated by GMP formation
How do we make GMP from IMP and what is regulated?
1. IMP DH (NADH)
2. GMP Synthetase (GLUTAMINE AMIDOTRANSFERASE, Uses 2 ATP)
Regulated by AMP formation
What does mycophenolic acid do?
Inhibits IMP DH
What do azaserine and acivicin do?
Block glutamine amidotransferaseses
Control of Purine Biosynthesis
PRPP Synthetase: I'd by ADP and GDP
GPAT: I'd by A and G stuff
What reaction does ribonucleotide reductase (RNR) catalyze?
NDPs to dNDPS!!!!!!!!
What are the regions of RNR?
Specificity Site
Activity Site
Catalytic Site
USES TYR Radicals
What is the ultimate reductant in RNR?
NADPH
What acts as the ON and OFF switch in RNR?
ATP and dATP
