BIOC 385 EXAM 3 questions well
answered passed
Which of the following is the reaction for nitric oxide synthase? - correct answer ✔✔L-arginine
+ 1.5 NADPH + H+ + 2O2mc073-2.jpg citrulline + NO + 1.5 NADP+
The shikimate pathway involves the ________________. - correct answer ✔✔condensation of
phosphoenolpyruvate and erythrose-4-phosphate.
What are the biochemical role of the E3 enzyme in the proteasomal degradation of proteins? -
correct answer ✔✔E3 functions as a target protein binding site to facilitate ubiquitination by E2.
Why is ingesting large amounts of L-arginine a viable treatment for argininosuccinase
deficiency? - correct answer ✔✔Arginine is converted to ornithine, which provides urea cycle
intermediates needed for nitrogen removal.
Which metabolite unique to the urea cycle connects the urea cycle to the citrate cycle through
the "Krebs bicycle" pathway? - correct answer ✔✔argininosuccinate
Angina patients sometimes carry nitroglycerine pills with them___________ - correct answer
✔✔as a rapid source of NO for blood vessel dilation
Regulation of protein ubiquitination is most often mediated by modification of_____________. -
correct answer ✔✔target proteins and E3 ligases
It is important that proteolytic enzymes in the lysosome are optimized to work at low pH
because low pH_____________. - correct answer ✔✔enhances protein denaturing.
,Diseases affecting heme biosynthesis as a result of deficiencies in the heme biosynthetic
pathway are called______________. - correct answer ✔✔porphyrias
What are the sources for the two nitrogens in urea? - correct answer ✔✔aspartate and
carbamoyl phosphate
What molecule signals the endothelial cell to produce NO? - correct answer ✔✔acetylcholine
A person who has phenylketonuria will have an excess amount of ___________ in the cell. -
correct answer ✔✔phenylalanine
Binding of ATP to the ______ subunit shifts ATCase to the ______ state, whereas ______ binding
to the regulatory subunit stabilizes the ______ state. - correct answer ✔✔regulatory; R; CTP; T
If HCO3mc012-1.jpg that is radioactively labeled with 13C is available, which carbon atom in the
molecule below would ultimately be expected to be radioactive? - correct answer ✔✔C (C=O)
Which of the following is a coenzyme that is derived from ATP? - correct answer ✔✔FAD
The disease ADA-SCID is due to __________ than normal activity of the enzyme __________. -
correct answer ✔✔lower; ribonucleotide reductase
15N-labeled aspartate is provided to bacteria during the biosynthesis of pyrimidine
trinucleotides. The radiolabeled nitrogen would ultimately be found in____________. - correct
answer ✔✔both UTP and CTP.
A mutation in ____________ would decrease the synthesis of both AMP and GMP. - correct
answer ✔✔PRPP synthetase
, Fluorodeoxyuridine-5-monophosphate is an inhibitor of the enzyme____________. - correct
answer ✔✔thymidylate synthase
In the human disease called severe combined immunodeficiency (ADA-SCID), ribonucleotide
reductase activity is __________ because of an overabundance of __________. - correct answer
✔✔inhibited; dATP
The conversion of hypoxanthine to IMP is catalyzed by __________, which is deficient in
__________. - correct answer ✔✔HGPRT; Lesch-Nyhan syndrome
Which enzyme activity would be directly inhibited by the addition of methotrexate? - correct
answer ✔✔dihydrofolate reductase
If the genomes of 100 different species were analyzed, gene sequences for which enzyme
required for deoxyribonucleotide biosynthesis would most likely be found in all of them? -
correct answer ✔✔ribonucleotide reductase
The conversion of ribose-1-phosphate to ATP via the salvage pathway would require the activity
of several enzymes. Choose the answer that lists them in the order that they would act in this
pathway. - correct answer ✔✔phosphopentomutase; PRPP synthetase; phosphoriboxyl
transferase; kinase; kinase
Five nucleotide bases are found in nucleic acids. Choose a pyrimidine/purine pair from the list
below. - correct answer ✔✔thymine and adenine
Nucleotide salvage pathways are favored in cells over de novo nucleotide synthesis because of
__________________. - correct answer ✔✔reduced energy expenditure
Put the following steps in the correct order for the ribonucleotide reductase reaction
mechanism. Step 1 of the six step reaction mechanism is shown above to help you get started. -
answered passed
Which of the following is the reaction for nitric oxide synthase? - correct answer ✔✔L-arginine
+ 1.5 NADPH + H+ + 2O2mc073-2.jpg citrulline + NO + 1.5 NADP+
The shikimate pathway involves the ________________. - correct answer ✔✔condensation of
phosphoenolpyruvate and erythrose-4-phosphate.
What are the biochemical role of the E3 enzyme in the proteasomal degradation of proteins? -
correct answer ✔✔E3 functions as a target protein binding site to facilitate ubiquitination by E2.
Why is ingesting large amounts of L-arginine a viable treatment for argininosuccinase
deficiency? - correct answer ✔✔Arginine is converted to ornithine, which provides urea cycle
intermediates needed for nitrogen removal.
Which metabolite unique to the urea cycle connects the urea cycle to the citrate cycle through
the "Krebs bicycle" pathway? - correct answer ✔✔argininosuccinate
Angina patients sometimes carry nitroglycerine pills with them___________ - correct answer
✔✔as a rapid source of NO for blood vessel dilation
Regulation of protein ubiquitination is most often mediated by modification of_____________. -
correct answer ✔✔target proteins and E3 ligases
It is important that proteolytic enzymes in the lysosome are optimized to work at low pH
because low pH_____________. - correct answer ✔✔enhances protein denaturing.
,Diseases affecting heme biosynthesis as a result of deficiencies in the heme biosynthetic
pathway are called______________. - correct answer ✔✔porphyrias
What are the sources for the two nitrogens in urea? - correct answer ✔✔aspartate and
carbamoyl phosphate
What molecule signals the endothelial cell to produce NO? - correct answer ✔✔acetylcholine
A person who has phenylketonuria will have an excess amount of ___________ in the cell. -
correct answer ✔✔phenylalanine
Binding of ATP to the ______ subunit shifts ATCase to the ______ state, whereas ______ binding
to the regulatory subunit stabilizes the ______ state. - correct answer ✔✔regulatory; R; CTP; T
If HCO3mc012-1.jpg that is radioactively labeled with 13C is available, which carbon atom in the
molecule below would ultimately be expected to be radioactive? - correct answer ✔✔C (C=O)
Which of the following is a coenzyme that is derived from ATP? - correct answer ✔✔FAD
The disease ADA-SCID is due to __________ than normal activity of the enzyme __________. -
correct answer ✔✔lower; ribonucleotide reductase
15N-labeled aspartate is provided to bacteria during the biosynthesis of pyrimidine
trinucleotides. The radiolabeled nitrogen would ultimately be found in____________. - correct
answer ✔✔both UTP and CTP.
A mutation in ____________ would decrease the synthesis of both AMP and GMP. - correct
answer ✔✔PRPP synthetase
, Fluorodeoxyuridine-5-monophosphate is an inhibitor of the enzyme____________. - correct
answer ✔✔thymidylate synthase
In the human disease called severe combined immunodeficiency (ADA-SCID), ribonucleotide
reductase activity is __________ because of an overabundance of __________. - correct answer
✔✔inhibited; dATP
The conversion of hypoxanthine to IMP is catalyzed by __________, which is deficient in
__________. - correct answer ✔✔HGPRT; Lesch-Nyhan syndrome
Which enzyme activity would be directly inhibited by the addition of methotrexate? - correct
answer ✔✔dihydrofolate reductase
If the genomes of 100 different species were analyzed, gene sequences for which enzyme
required for deoxyribonucleotide biosynthesis would most likely be found in all of them? -
correct answer ✔✔ribonucleotide reductase
The conversion of ribose-1-phosphate to ATP via the salvage pathway would require the activity
of several enzymes. Choose the answer that lists them in the order that they would act in this
pathway. - correct answer ✔✔phosphopentomutase; PRPP synthetase; phosphoriboxyl
transferase; kinase; kinase
Five nucleotide bases are found in nucleic acids. Choose a pyrimidine/purine pair from the list
below. - correct answer ✔✔thymine and adenine
Nucleotide salvage pathways are favored in cells over de novo nucleotide synthesis because of
__________________. - correct answer ✔✔reduced energy expenditure
Put the following steps in the correct order for the ribonucleotide reductase reaction
mechanism. Step 1 of the six step reaction mechanism is shown above to help you get started. -
