DHN 311 CORE EXAMS SET 2025/2026 QUESTIONS WITH
SOLUTIONS RATED A+
✔✔the liver and pancreas - ✔✔In what two places is glucokinase present?
✔✔muscle and the brain - ✔✔In what two places is hexokinase present?
✔✔high; lower - ✔✔Glucokinase has a _____ Km, and hexokinase has a ______ Km.
✔✔-the enzymes in muscle and the brain can still function when blood sugar is low
-more steady state of activity (glycolysis) in these tissues - ✔✔Why is it a good thing
that hexokinase has a lower Km?
✔✔it helps us maintain regular blood sugar levels (liver effectively removes flood of
glucose from the blood after a meal, enzyme in pancreas acts like a "sugar sensor" for
insulin secretion - ✔✔Why is it a good thing that glucokinase has a high Km?
✔✔regulatory; converting it to another sugar; storing it - ✔✔The PFK1 reaction is an
important ________ site. This step commits the cell to metabolize glucose rather than
..... or .....
✔✔blood glucose levels; phosphorylation - ✔✔PFKI can be regulated by ______
______ _______, mediated by the hormones glucagon and insulin. This involves
__________ of the enzyme.
✔✔-ATP
-AMP
-citrate
-fructose 2, 6 bisphosphate (F26BP) - ✔✔the four regulators of PFK1
✔✔ATP and citrate - ✔✔the two regulators that inhibit PFK1
✔✔AMP and F26BP - ✔✔the two regulators that activate PFK1
✔✔citrate - ✔✔an important TCA cycle intermediate that also acts as a regulator for
PFK1
✔✔F26BP - ✔✔the most potent regulator of PFK1 (can override the presence of other
inhibitors)
✔✔increases - ✔✔PFK1 velocity ______ with decreased concentrations of ATP.
, ✔✔inhibits; decrease - ✔✔In the fed state, there is an increased amount of ATP, which
_______ PFK1. When high levels of energy in the cell are already present, PFK1
activity will ________ the rate of glycolysis (in MOST tissues).
✔✔F26BP; activates; increased - ✔✔In the fed state in the LIVER, _______ increases,
which consequently _______ PFK1. This causes a(n) ________ rate of glycolysis.
✔✔phosphofructokinase 2 (PFK2) - ✔✔an enzyme found in the liver that
phosphorylates fructose-6-phosphate
✔✔insulin - ✔✔What hormone activates PFK2?
✔✔acetyl-CoA; fatty acids - ✔✔When PFK2 is activated (in the liver), excess glucose is
converted to ________ and ultimately ______ ______.
✔✔through the formation of acetyl-CoA - ✔✔When someone consumes excess carbs,
how is it converted to fat?
✔✔It has a double bond that imparts high energy to the phosphate bond - ✔✔Why is
phosphoenolpyruvate (PEP) high in energy?
✔✔PEP; ATP - ✔✔Transfer of the phosphate group from _____ to ____ converts PEP
to pyruvate.
✔✔AMP and F16BP (feeds forward) - ✔✔regulators that activate pyruvate kinase
✔✔ATP and alanine - ✔✔regulators that inhibit pyruvate kinase
✔✔pyruvate is easily converted into alanine - ✔✔Why does alanine inhibit pyruvate
kinase?
✔✔liver; blood glucose level - ✔✔In the ______, pyruvate kinase is regulated by a
covalent modification through phosphorylation. The phosphorylation of pyruvate kinase
is regulated by _____ ____ _____, just like PFK1.
✔✔low; off - ✔✔When blood sugar is _____, pyruvate kinase is phosphorylated. This
turns on/off the enzyme.
✔✔gluconeogensis - ✔✔When blood sugar is low and pyruvate kinase is turned off,
PEP can instead enter ________.
✔✔catabolic; anabolic; CO2; reducing equivalents - ✔✔The TCA cycle is a common
and final _______ and ______ pathways of the macronutrients we consume. This is
SOLUTIONS RATED A+
✔✔the liver and pancreas - ✔✔In what two places is glucokinase present?
✔✔muscle and the brain - ✔✔In what two places is hexokinase present?
✔✔high; lower - ✔✔Glucokinase has a _____ Km, and hexokinase has a ______ Km.
✔✔-the enzymes in muscle and the brain can still function when blood sugar is low
-more steady state of activity (glycolysis) in these tissues - ✔✔Why is it a good thing
that hexokinase has a lower Km?
✔✔it helps us maintain regular blood sugar levels (liver effectively removes flood of
glucose from the blood after a meal, enzyme in pancreas acts like a "sugar sensor" for
insulin secretion - ✔✔Why is it a good thing that glucokinase has a high Km?
✔✔regulatory; converting it to another sugar; storing it - ✔✔The PFK1 reaction is an
important ________ site. This step commits the cell to metabolize glucose rather than
..... or .....
✔✔blood glucose levels; phosphorylation - ✔✔PFKI can be regulated by ______
______ _______, mediated by the hormones glucagon and insulin. This involves
__________ of the enzyme.
✔✔-ATP
-AMP
-citrate
-fructose 2, 6 bisphosphate (F26BP) - ✔✔the four regulators of PFK1
✔✔ATP and citrate - ✔✔the two regulators that inhibit PFK1
✔✔AMP and F26BP - ✔✔the two regulators that activate PFK1
✔✔citrate - ✔✔an important TCA cycle intermediate that also acts as a regulator for
PFK1
✔✔F26BP - ✔✔the most potent regulator of PFK1 (can override the presence of other
inhibitors)
✔✔increases - ✔✔PFK1 velocity ______ with decreased concentrations of ATP.
, ✔✔inhibits; decrease - ✔✔In the fed state, there is an increased amount of ATP, which
_______ PFK1. When high levels of energy in the cell are already present, PFK1
activity will ________ the rate of glycolysis (in MOST tissues).
✔✔F26BP; activates; increased - ✔✔In the fed state in the LIVER, _______ increases,
which consequently _______ PFK1. This causes a(n) ________ rate of glycolysis.
✔✔phosphofructokinase 2 (PFK2) - ✔✔an enzyme found in the liver that
phosphorylates fructose-6-phosphate
✔✔insulin - ✔✔What hormone activates PFK2?
✔✔acetyl-CoA; fatty acids - ✔✔When PFK2 is activated (in the liver), excess glucose is
converted to ________ and ultimately ______ ______.
✔✔through the formation of acetyl-CoA - ✔✔When someone consumes excess carbs,
how is it converted to fat?
✔✔It has a double bond that imparts high energy to the phosphate bond - ✔✔Why is
phosphoenolpyruvate (PEP) high in energy?
✔✔PEP; ATP - ✔✔Transfer of the phosphate group from _____ to ____ converts PEP
to pyruvate.
✔✔AMP and F16BP (feeds forward) - ✔✔regulators that activate pyruvate kinase
✔✔ATP and alanine - ✔✔regulators that inhibit pyruvate kinase
✔✔pyruvate is easily converted into alanine - ✔✔Why does alanine inhibit pyruvate
kinase?
✔✔liver; blood glucose level - ✔✔In the ______, pyruvate kinase is regulated by a
covalent modification through phosphorylation. The phosphorylation of pyruvate kinase
is regulated by _____ ____ _____, just like PFK1.
✔✔low; off - ✔✔When blood sugar is _____, pyruvate kinase is phosphorylated. This
turns on/off the enzyme.
✔✔gluconeogensis - ✔✔When blood sugar is low and pyruvate kinase is turned off,
PEP can instead enter ________.
✔✔catabolic; anabolic; CO2; reducing equivalents - ✔✔The TCA cycle is a common
and final _______ and ______ pathways of the macronutrients we consume. This is
