BIOC 384 – EXAM 3 2025 WITH ACCURATE
SOLUTION
We eat foods containing sucrose (tablesugar),
lactose (milk sugar), and cellobiose(disaccharide of
cellulose in plants).
How many netmoles of ATP per mole disaccharide
do humansgenerate from the disaccharides
sucrose, lactose,and cellobiose using the glycolytic
pathway? – Answer✅ ☑️
️sucrose: 4 ATP; lactose: 4 ATP;
cellobiose: 0 ATP
Which metabolic pathway is an example of a
catabolic pathway in animals? – Answer✅☑️
️Glycogen
degradation
A regulatory enzyme that controls cell division
undergoes a mutation preventing it from
beingphosphorylated at a Ser residue required for
activation. However, the amino acid that replaces
Ser results inthe enzyme being catalytically active
even though this amino acid replacement is not
phosphorylated.
,1) Which amino acid listed below could be the
replacement amino acid that fits the description
above?
2) What is the most likely explanation for why the
mutated enzyme results in cancer cell growth?
3) Which amino acid listed below could be a
replacement amino acid that results in an inactive
enzyme? – Answer✅ ☑️
️1) Asp, 2) The regulatory
enzyme cannot be inhibited by a phosphatase
enzyme, 3) Gly
Competitive inhibitors alter the Km , but not the
Vmax ,uncompetitive inhibitors alter the Vmax and
the Km , mixed inhibitorsdecrease Vmax and
increase or decrease Km , and
noncompetitiveinhibitors decrease Vmax , but do
not alter the K m . Identify each ofthe inhibitors
depicted in the box to the right as
functionaldiagrams (1 and 2), or in L-B plots (3 and
4) – Answer✅ ☑️
️ 1) uncompetitive inhibitor, 2)
competitive inhibitor,3) uncompetitive inhibitor, 4)
competitive inhibitor
Put the following nine signaling events in the
correct order starting with release of insulin from
,thepancreatic beta cells and ending with increased
glucose uptake into cells by GLUT4 glucose
transporter.
___Tyrosine phosphorylation of insulin receptor
substrate-1.
___Binding of IRS-1 to phosphotyrosine on the
insulin receptor.
___Phosphorylation of downstream target proteins
by Akt.
___Binding of phosphoinositide 3-kinase to
phosphotyrosine on IRS-1.
___Insulin binding to one of the a subunits of the
insulin receptor.
___PDK-1 and Akt binding to phosphatidylinositol-
3,4,5-trisphosphate.
___Phosphorylation of phosphatidylinositol-4,5-
bisphosphate by PI3K.
___Tyr phosphorylation of the cytosolic domains of
insulin receptor.
___PDK-1 phosphorylation and activation of Akt
kinase activity. – Answer✅☑️
️4, 3, 9, 5, 1, 7, 6, 2, 8
, Dexamethasone (Dex) is a high affinity ligand for
the glucocorticoid receptor (GR), which hasbeen
used as an anti-inflammatory drug to treat
rheumatoid arthritis. What is the molecular
explanation forwhy Dex is 50 times more potent in
treating inflammation than the natural
glucocorticoid cortisol? – Answer✅☑️
️Dex binding to
GR is 50 times more efficient at shifting GR to the
active R state conformation
Metabolic flux is regulated by availability of
substrates and enzymeactivity. Using the table
below, match the mechanism by which enzyme
activity isregulated (A, B, C) with example(s) of the
most common modes of cellularregulation (1-9).
Examples of cellular regulation are used once,
more than once,or not all. All examples of enzyme
regulation are used at least once.
Enzyme Regulation
A. Enzyme levels
B. Catalytic activity
C. Compartmentation
Cellular Respiration
1. Allosteric control
SOLUTION
We eat foods containing sucrose (tablesugar),
lactose (milk sugar), and cellobiose(disaccharide of
cellulose in plants).
How many netmoles of ATP per mole disaccharide
do humansgenerate from the disaccharides
sucrose, lactose,and cellobiose using the glycolytic
pathway? – Answer✅ ☑️
️sucrose: 4 ATP; lactose: 4 ATP;
cellobiose: 0 ATP
Which metabolic pathway is an example of a
catabolic pathway in animals? – Answer✅☑️
️Glycogen
degradation
A regulatory enzyme that controls cell division
undergoes a mutation preventing it from
beingphosphorylated at a Ser residue required for
activation. However, the amino acid that replaces
Ser results inthe enzyme being catalytically active
even though this amino acid replacement is not
phosphorylated.
,1) Which amino acid listed below could be the
replacement amino acid that fits the description
above?
2) What is the most likely explanation for why the
mutated enzyme results in cancer cell growth?
3) Which amino acid listed below could be a
replacement amino acid that results in an inactive
enzyme? – Answer✅ ☑️
️1) Asp, 2) The regulatory
enzyme cannot be inhibited by a phosphatase
enzyme, 3) Gly
Competitive inhibitors alter the Km , but not the
Vmax ,uncompetitive inhibitors alter the Vmax and
the Km , mixed inhibitorsdecrease Vmax and
increase or decrease Km , and
noncompetitiveinhibitors decrease Vmax , but do
not alter the K m . Identify each ofthe inhibitors
depicted in the box to the right as
functionaldiagrams (1 and 2), or in L-B plots (3 and
4) – Answer✅ ☑️
️ 1) uncompetitive inhibitor, 2)
competitive inhibitor,3) uncompetitive inhibitor, 4)
competitive inhibitor
Put the following nine signaling events in the
correct order starting with release of insulin from
,thepancreatic beta cells and ending with increased
glucose uptake into cells by GLUT4 glucose
transporter.
___Tyrosine phosphorylation of insulin receptor
substrate-1.
___Binding of IRS-1 to phosphotyrosine on the
insulin receptor.
___Phosphorylation of downstream target proteins
by Akt.
___Binding of phosphoinositide 3-kinase to
phosphotyrosine on IRS-1.
___Insulin binding to one of the a subunits of the
insulin receptor.
___PDK-1 and Akt binding to phosphatidylinositol-
3,4,5-trisphosphate.
___Phosphorylation of phosphatidylinositol-4,5-
bisphosphate by PI3K.
___Tyr phosphorylation of the cytosolic domains of
insulin receptor.
___PDK-1 phosphorylation and activation of Akt
kinase activity. – Answer✅☑️
️4, 3, 9, 5, 1, 7, 6, 2, 8
, Dexamethasone (Dex) is a high affinity ligand for
the glucocorticoid receptor (GR), which hasbeen
used as an anti-inflammatory drug to treat
rheumatoid arthritis. What is the molecular
explanation forwhy Dex is 50 times more potent in
treating inflammation than the natural
glucocorticoid cortisol? – Answer✅☑️
️Dex binding to
GR is 50 times more efficient at shifting GR to the
active R state conformation
Metabolic flux is regulated by availability of
substrates and enzymeactivity. Using the table
below, match the mechanism by which enzyme
activity isregulated (A, B, C) with example(s) of the
most common modes of cellularregulation (1-9).
Examples of cellular regulation are used once,
more than once,or not all. All examples of enzyme
regulation are used at least once.
Enzyme Regulation
A. Enzyme levels
B. Catalytic activity
C. Compartmentation
Cellular Respiration
1. Allosteric control
