BIOC 385 Exam 3 questions with
complete solutions rated A+
- correct answer ✔✔Module 7
A. cleaves trypsinogen to form trypsin - correct answer ✔✔In the duodenum, enter peptidase
_______________.
A. cleaves trypsinogen to form trypsin
B. neutralizes the pH of the duodenum to a pH of 7
C. generates peptides and amino acids
D. cleaves chymotrypsin to form chymotrypsin
D. E3 - correct answer ✔✔Which of the three proteins in the ubiquination pathway is the most
responsible for recognizing the ubiquinated target protein?
A. all three of the proteins recognize the target protein
B. E2
C. E1
D. E3
D. arginine stimulates the production of the allosteric activator N-acetylglutamate - correct
answer ✔✔What is the regulatory mechanism by which arginine stimulates flux through the
urea cycle?
A. arginine stimulates flux through the urea cycle by inhibiting the enzyme nitrogenase
,B. arginine stimulates the production of N-acetylglutamate which activates arginase
C. arginine stimulates the activity of carbamoyl phosphate synthetase I
D. arginine stimulates the production of the allosteric activator N-acetylglutamate
D. oxidation of homogentisate - correct answer ✔✔A person who has alkaptonuria is easily
diagnosed from their black urine. What causes the black odor?
A. reduction of acetoacetyl-CoA
B. oxidation of phenylalanine
C. phenylpyruvate and phenylacetate
D. oxidation of homogentisate
D. nonessential; aspartate could be synthesized from other intermediates - correct answer
✔✔Aspartate is a(n) _____________ amino acid, so if a person had a diet that contained no
aspartate then _____________.
A. nonessential; they would be unable to synthesize proteins
B. essential; they would be unable to synthesize proteins
C. essential; aspartate could be synthesized from other intermediates
D. nonessential; aspartate could be synthesized from other intermediates
D. glyphosate is a competitive inhibitor of the plant EPSP synthase - correct answer ✔✔What is
the mechanism by which glyphosate, the active ingredient in RoundUp, kills plants?
A. glyphosate inhibits the production of aspartate, alanine, and glycine
B. glyphosate is an allosteric activator to plant EPSP synthase
C. glyphosate binds to tyrosine and prevents incorporation into proteins
,D. glyphosate is a competitive inhibitor of the plant EPSP synthase
D. porphyria - correct answer ✔✔Disease affecting heme biosynthesis as a result of deficiencies
in the heme biosynthetic pathway are called
A. albinism
B. alkaptonuria
C. phenylketonuria
D. porphyria
C. NH+ + HCO3 + aspartate + 3ATP urea + fumerate + 2 ADP + 2Pi + AMP + PPi - correct answer
✔✔Which of the following is the net reaction of the urea cycle?
A. NH+ + HCO3 + fumerate + 3ATP urea + aspartate + 2 ADP + 2Pi + AMP + PPi
B. NH+ + HCO3 + aspartate + 2 ADP + 2Pi + AMP + PPi urea + fumerate + 3ATP
C. NH+ + HCO3 + aspartate + 3ATP urea + fumerate + 2 ADP + 2Pi + AMP + PPi
D. Urea + Fumerate + 2 ADP + 2Pi + AMP + PPi NH+ + HCO3- + aspartate + 3ATP
E. Tyrosine can be synthesized from phenylalanine, and since phenylalanine is essential, tyrosine
is not. - correct answer ✔✔Animals cannot synthesize tyrosine from shikimate-3P because they
lack EPSP synthase. However, tyrosine is listed as a non-essential amino acid in most tables.
What is the explanation?
A. Tyrosine is essential until reaching puberty, and then after that, it is non-essential because of
hormones.
, B. Tyrosine is not essential because it can be synthesized from tryptophan, and tryptophan is
essential.
C. There are other pathways to synthesize tyrosine from shikimate-3P, so EPSP synthase is not
required.
D. Most animals do actually contain the enzyme EPSP synthase it is just not expressed all of the
time.
E. Tyrosine can be synthesized from phenylalanine, and since phenylalanine is essential, tyrosine
is not.
E. as a rapid source of NO for blood vessel dilation - correct answer ✔✔Angina patients
sometimes carry nitroglycerine pills with them___________
A. to inhibit acetylcholine release from neurons
B. as a source of ammonia for muscle relaxation
C. to increase heart rate during a heart attack.
D. to inhibit cGMP phosphodiesterase
E. as a rapid source of NO for blood vessel dilation
A. aspartate and carbamoyl phosphate - correct answer ✔✔What are the sources for the two
nitrogens in urea?
A. aspartate and carbamoyl phosphate
B. glutamate and glutamine
C. asparagine and glutamine
complete solutions rated A+
- correct answer ✔✔Module 7
A. cleaves trypsinogen to form trypsin - correct answer ✔✔In the duodenum, enter peptidase
_______________.
A. cleaves trypsinogen to form trypsin
B. neutralizes the pH of the duodenum to a pH of 7
C. generates peptides and amino acids
D. cleaves chymotrypsin to form chymotrypsin
D. E3 - correct answer ✔✔Which of the three proteins in the ubiquination pathway is the most
responsible for recognizing the ubiquinated target protein?
A. all three of the proteins recognize the target protein
B. E2
C. E1
D. E3
D. arginine stimulates the production of the allosteric activator N-acetylglutamate - correct
answer ✔✔What is the regulatory mechanism by which arginine stimulates flux through the
urea cycle?
A. arginine stimulates flux through the urea cycle by inhibiting the enzyme nitrogenase
,B. arginine stimulates the production of N-acetylglutamate which activates arginase
C. arginine stimulates the activity of carbamoyl phosphate synthetase I
D. arginine stimulates the production of the allosteric activator N-acetylglutamate
D. oxidation of homogentisate - correct answer ✔✔A person who has alkaptonuria is easily
diagnosed from their black urine. What causes the black odor?
A. reduction of acetoacetyl-CoA
B. oxidation of phenylalanine
C. phenylpyruvate and phenylacetate
D. oxidation of homogentisate
D. nonessential; aspartate could be synthesized from other intermediates - correct answer
✔✔Aspartate is a(n) _____________ amino acid, so if a person had a diet that contained no
aspartate then _____________.
A. nonessential; they would be unable to synthesize proteins
B. essential; they would be unable to synthesize proteins
C. essential; aspartate could be synthesized from other intermediates
D. nonessential; aspartate could be synthesized from other intermediates
D. glyphosate is a competitive inhibitor of the plant EPSP synthase - correct answer ✔✔What is
the mechanism by which glyphosate, the active ingredient in RoundUp, kills plants?
A. glyphosate inhibits the production of aspartate, alanine, and glycine
B. glyphosate is an allosteric activator to plant EPSP synthase
C. glyphosate binds to tyrosine and prevents incorporation into proteins
,D. glyphosate is a competitive inhibitor of the plant EPSP synthase
D. porphyria - correct answer ✔✔Disease affecting heme biosynthesis as a result of deficiencies
in the heme biosynthetic pathway are called
A. albinism
B. alkaptonuria
C. phenylketonuria
D. porphyria
C. NH+ + HCO3 + aspartate + 3ATP urea + fumerate + 2 ADP + 2Pi + AMP + PPi - correct answer
✔✔Which of the following is the net reaction of the urea cycle?
A. NH+ + HCO3 + fumerate + 3ATP urea + aspartate + 2 ADP + 2Pi + AMP + PPi
B. NH+ + HCO3 + aspartate + 2 ADP + 2Pi + AMP + PPi urea + fumerate + 3ATP
C. NH+ + HCO3 + aspartate + 3ATP urea + fumerate + 2 ADP + 2Pi + AMP + PPi
D. Urea + Fumerate + 2 ADP + 2Pi + AMP + PPi NH+ + HCO3- + aspartate + 3ATP
E. Tyrosine can be synthesized from phenylalanine, and since phenylalanine is essential, tyrosine
is not. - correct answer ✔✔Animals cannot synthesize tyrosine from shikimate-3P because they
lack EPSP synthase. However, tyrosine is listed as a non-essential amino acid in most tables.
What is the explanation?
A. Tyrosine is essential until reaching puberty, and then after that, it is non-essential because of
hormones.
, B. Tyrosine is not essential because it can be synthesized from tryptophan, and tryptophan is
essential.
C. There are other pathways to synthesize tyrosine from shikimate-3P, so EPSP synthase is not
required.
D. Most animals do actually contain the enzyme EPSP synthase it is just not expressed all of the
time.
E. Tyrosine can be synthesized from phenylalanine, and since phenylalanine is essential, tyrosine
is not.
E. as a rapid source of NO for blood vessel dilation - correct answer ✔✔Angina patients
sometimes carry nitroglycerine pills with them___________
A. to inhibit acetylcholine release from neurons
B. as a source of ammonia for muscle relaxation
C. to increase heart rate during a heart attack.
D. to inhibit cGMP phosphodiesterase
E. as a rapid source of NO for blood vessel dilation
A. aspartate and carbamoyl phosphate - correct answer ✔✔What are the sources for the two
nitrogens in urea?
A. aspartate and carbamoyl phosphate
B. glutamate and glutamine
C. asparagine and glutamine
