Biochemistry Practice Exams for
Exam 4 UTD SPIRO BIOL3361 fully
solved passed
Gluconeogenesis is the synthesis of
a. glucose from non-carbohydrate precursors.
b.glycogen from glucose.
c.pyruvate from glucose.
d.fatty acids from glucose.
e.glucose from fatty acids. - correct answer ✔✔A - glucose from non-carbohydrate precursors.
In the gluconeogenic pathway, the three _____ regulated reactions of glycolysis catalyzed by
_____________, ____________ and __________ are replaced by alternative reactions.
a. exergonic; hexokinase; PFK 1; pyruvate kinase
b. exergonic; phosphoglucoisomerase; PFK 1; pyruvate kinase
c. exergonic; PFK 1; triose phosphate isomerase; pyruvate kinase
,d. endergonic; glucoseglucokinase; PFK 1; glyceraldehyde-3-phosphate
dehydrogenase
e. endergonic; glucokinase; PFK 1; pyruvate carboxylase - correct answer ✔✔A - exergonic;
hexokinase; PFK 1; pyruvate kinase
All are enzymes unique to gluconeogenesis that are not shared with glycolysis EXCEPT:
a. phosphoglucoisomerase
b. glucose-6-phosphatase.
c. pyruvate carboxylase.
d. fructose-1,6-bisphosphatase
e. PEP carboxykinase. - correct answer ✔✔A - phophoglucoisomerase
Glucose-6-phosphatase is located in the __________ and produces __________
a. mitochondria; lactate
b. cytosol; glucose
c. endoplasmic reticulum; glucose-6-phosphate
,d. endoplasmic reticulum; glucose
e. cytosol; glucose-6-phosphate - correct answer ✔✔D - endoplasmic reticulum; glucose
Gluconeogenesis is not simply reversal of glycolysis since the conversion of 2 pyruvate -->
glucose by gluconeogenesis requires _____ molecules of ATP/GTP. - correct answer ✔✔6
The highly _________ polysaccharides called limit dextrins are degraded by the action of
___________ which has two distinct enzymatic activities known as ______________ and
_______________.
a. branched; a-amylase; glycogen phosphorylase; a(1→6)glucosidase
b. branched; debranching enzyme; glucanotransferase; a(1→6)glucosidase
c. linear; debranching enzyme; glucanotransferase; a(1→6)glucosidase
d. branched; debranching enzyme; a-amylase; a(1→6)glucosidase
e. linear; a-amylase; gluconotransferase; glycogen phosphorylase - correct answer ✔✔B -
branched; debranching enzyme; glucanotransferase; α(1→6)glucosidase
The activity of glycogen phosphorylase is:
a. the conversion of glucose-1-phosphate to glucose-6-phosphate.
b. the hydrolysis of ATP.
, c. the phosphorolysis of glycogen to generate glucose-1-phosphate.
d. to inhibit the production of glucose-1-phosphate.
e. to synthesize glycogen. - correct answer ✔✔C - the phosphorolysis of glycogen to generate
glucose-1-phosphate.
Which statement is a correct description of the mechanisms of regulation of glycogen
phosphorylase?
a. phosphorylase 'b' is phosphorylated, and is allosterically activated by AMP.
b. phosphorylase 'a' and phosphorylase 'b' are interconverted by the allosteric regulator AMP.
c. phosphorylase 'a' is phosphorylated, and is persistently active.
d. phosphorylase 'a' is not phosphorylated, and is allosterically activated by AMP.
e. phosphorylase 'b' is not subject to allosteric regulation by AMP - correct answer ✔✔C -
phosphorylase 'a' is phosphorylated, and is
persistently active.
The correct sequence for the hormone-activated enzymatic cascade that leads to activation of
glycogen phosphorylase is:
A. Phosphorylation of phosphorylase kinase to activate it
Exam 4 UTD SPIRO BIOL3361 fully
solved passed
Gluconeogenesis is the synthesis of
a. glucose from non-carbohydrate precursors.
b.glycogen from glucose.
c.pyruvate from glucose.
d.fatty acids from glucose.
e.glucose from fatty acids. - correct answer ✔✔A - glucose from non-carbohydrate precursors.
In the gluconeogenic pathway, the three _____ regulated reactions of glycolysis catalyzed by
_____________, ____________ and __________ are replaced by alternative reactions.
a. exergonic; hexokinase; PFK 1; pyruvate kinase
b. exergonic; phosphoglucoisomerase; PFK 1; pyruvate kinase
c. exergonic; PFK 1; triose phosphate isomerase; pyruvate kinase
,d. endergonic; glucoseglucokinase; PFK 1; glyceraldehyde-3-phosphate
dehydrogenase
e. endergonic; glucokinase; PFK 1; pyruvate carboxylase - correct answer ✔✔A - exergonic;
hexokinase; PFK 1; pyruvate kinase
All are enzymes unique to gluconeogenesis that are not shared with glycolysis EXCEPT:
a. phosphoglucoisomerase
b. glucose-6-phosphatase.
c. pyruvate carboxylase.
d. fructose-1,6-bisphosphatase
e. PEP carboxykinase. - correct answer ✔✔A - phophoglucoisomerase
Glucose-6-phosphatase is located in the __________ and produces __________
a. mitochondria; lactate
b. cytosol; glucose
c. endoplasmic reticulum; glucose-6-phosphate
,d. endoplasmic reticulum; glucose
e. cytosol; glucose-6-phosphate - correct answer ✔✔D - endoplasmic reticulum; glucose
Gluconeogenesis is not simply reversal of glycolysis since the conversion of 2 pyruvate -->
glucose by gluconeogenesis requires _____ molecules of ATP/GTP. - correct answer ✔✔6
The highly _________ polysaccharides called limit dextrins are degraded by the action of
___________ which has two distinct enzymatic activities known as ______________ and
_______________.
a. branched; a-amylase; glycogen phosphorylase; a(1→6)glucosidase
b. branched; debranching enzyme; glucanotransferase; a(1→6)glucosidase
c. linear; debranching enzyme; glucanotransferase; a(1→6)glucosidase
d. branched; debranching enzyme; a-amylase; a(1→6)glucosidase
e. linear; a-amylase; gluconotransferase; glycogen phosphorylase - correct answer ✔✔B -
branched; debranching enzyme; glucanotransferase; α(1→6)glucosidase
The activity of glycogen phosphorylase is:
a. the conversion of glucose-1-phosphate to glucose-6-phosphate.
b. the hydrolysis of ATP.
, c. the phosphorolysis of glycogen to generate glucose-1-phosphate.
d. to inhibit the production of glucose-1-phosphate.
e. to synthesize glycogen. - correct answer ✔✔C - the phosphorolysis of glycogen to generate
glucose-1-phosphate.
Which statement is a correct description of the mechanisms of regulation of glycogen
phosphorylase?
a. phosphorylase 'b' is phosphorylated, and is allosterically activated by AMP.
b. phosphorylase 'a' and phosphorylase 'b' are interconverted by the allosteric regulator AMP.
c. phosphorylase 'a' is phosphorylated, and is persistently active.
d. phosphorylase 'a' is not phosphorylated, and is allosterically activated by AMP.
e. phosphorylase 'b' is not subject to allosteric regulation by AMP - correct answer ✔✔C -
phosphorylase 'a' is phosphorylated, and is
persistently active.
The correct sequence for the hormone-activated enzymatic cascade that leads to activation of
glycogen phosphorylase is:
A. Phosphorylation of phosphorylase kinase to activate it
