UNE BIOCHEMISTRY 2026 STUDY GUIDE QUESTIONS AND
ANSWERS GUARANTEE A+
✔✔Adenylyl cyclase - ✔✔Glycogen degradation in the liver can be enhanced by
elevated glucagon and the activation of a Gαs receptor. The initial step in this cascade
involves which of the following second messengers or active enzymes?
✔✔2 - ✔✔Which of the following combinations of compounds is required to fully activate
pyruvate carboxylase (+ indicates compound is necessary; - indicates compound is not
necessary)?
1. Biotin + Acetyl-CoA + Oxaloacetate + Malate -
2. Biotin + Acetyl-CoA + Oxaloacetate - Malate -
3. Biotin - Acetyl-CoA + Oxaloacetate + Malate +
4. Biotin - Acetyl-CoA - Oxaloacetate + Malate +
✔✔Acetyl-CoA - ✔✔Which of the following compounds is not a substrate for
gluconeogenesis?
✔✔Pyruvate carboxylase deficiency - ✔✔A 1-month-old boy is brought to the
emergency department in a coma after sleeping through the night and failing to awaken
in the morning. He is given intravenous glucose and awakens. Serum levels of
pyruvate, lactate, and alanine are elevated, whereas oxaloacetate and aspartate levels
are reduced. Which of the following is the most likely diagnosis in this patient?
✔✔Generation of glucose 1-phosphate to be used for glycogen synthesis - ✔✔Which of
the following would occur in the liver when glucose levels are high (think insulin is
elevated)?
✔✔The process using lactate from skeletal muscle and red blood cells to generate
glucose - ✔✔Which of the following best describes the role of the Cori cycle?
✔✔Fructose 2,6-bisphosphate - ✔✔Which of the following compounds allosterically
activates phosphofructokinase-1 (PFK1)?
✔✔The phosphorylation and inactivation of E1 subunit of PDC (pyruvate
dehydrogenase complex) - ✔✔Pyruvate dehydrogenase kinase catalyzes a reaction
that results in which of the following?
✔✔Pyruvate dehydrogenase complex; pyruvate - ✔✔Which of the following enzymes is
correctly paired with its activator?
✔✔Aconitase - ✔✔A farmer finds a cow dead in his field and notices an unusual plant
nearby. Autopsy results show an elevated level of citrate present in the cow's
, mitochondria. This data collectively suggest inhibition of which of the following
enzymes?
✔✔Succinate thiokinase - ✔✔A 10-year-old girl is swimming in a local competition. The
intense exercise will increase intracellular calcium levels which in turn will increase flux
through the TCA cycle by stimulating the activity of all of the following enzymes
EXCEPT?
✔✔Alanine - ✔✔Glycolysis provides intermediates that can be used to make other
necessary substrates. One example of this is the direct conversion of pyruvate to which
of the following amino acids?
✔✔Pyruvate - ✔✔Pyruvate dehydrogenase complex is highly regulated. The enzyme
will be most active when which of the following compounds is high?
✔✔Increased activity of pyruvate kinase - ✔✔A newborn is determined to have
hyperinsulinemia. Which of the following is likely to occur as a result of this deficiency?
✔✔Electrons are directly transferred from glycerol 3-phosphate to an FAD containing
glycerol phosphate dehydrogenase - ✔✔The glycerophosphate shuttle is the major
shuttle of most tissues. Which of the following best describes the transfer of electrons
by this shuttle?
✔✔Two electrons and two protons - ✔✔The fully reduced quinol form of CoQ contains
which of the following combinations of electrons and protons?
✔✔-3 - ✔✔A series of reactions have the following ΔG. A + B --> C ΔG = -1 C + D --> E
ΔG = +3 E + F --> G ΔG = -5 The overall ΔG for this series of reactions is determined to
be which of the following values?
✔✔The pH is higher in the matrix when compared to the intermembrane space. - ✔✔As
electrons flow through complexes in the inner mitochondrial membrane, protons are
pumped from the matrix to the intermembrane space. Which of the following statements
is most reflective of the pH in the intermembrane space?
✔✔NADH → complex I → CoQ → complex III → cyt c → complex IV - ✔✔Which of the
following describes a correct and complete electron transfer pathway necessary for
oxidative phosphorylation?
✔✔Pump protons from the mitochondrial matrix to the intermembrane space -
✔✔Complex II (Succinate Q-reductase) is not considered to be part of the process of
oxidative phosphorylation because it is unable to do which of the following activities?
ANSWERS GUARANTEE A+
✔✔Adenylyl cyclase - ✔✔Glycogen degradation in the liver can be enhanced by
elevated glucagon and the activation of a Gαs receptor. The initial step in this cascade
involves which of the following second messengers or active enzymes?
✔✔2 - ✔✔Which of the following combinations of compounds is required to fully activate
pyruvate carboxylase (+ indicates compound is necessary; - indicates compound is not
necessary)?
1. Biotin + Acetyl-CoA + Oxaloacetate + Malate -
2. Biotin + Acetyl-CoA + Oxaloacetate - Malate -
3. Biotin - Acetyl-CoA + Oxaloacetate + Malate +
4. Biotin - Acetyl-CoA - Oxaloacetate + Malate +
✔✔Acetyl-CoA - ✔✔Which of the following compounds is not a substrate for
gluconeogenesis?
✔✔Pyruvate carboxylase deficiency - ✔✔A 1-month-old boy is brought to the
emergency department in a coma after sleeping through the night and failing to awaken
in the morning. He is given intravenous glucose and awakens. Serum levels of
pyruvate, lactate, and alanine are elevated, whereas oxaloacetate and aspartate levels
are reduced. Which of the following is the most likely diagnosis in this patient?
✔✔Generation of glucose 1-phosphate to be used for glycogen synthesis - ✔✔Which of
the following would occur in the liver when glucose levels are high (think insulin is
elevated)?
✔✔The process using lactate from skeletal muscle and red blood cells to generate
glucose - ✔✔Which of the following best describes the role of the Cori cycle?
✔✔Fructose 2,6-bisphosphate - ✔✔Which of the following compounds allosterically
activates phosphofructokinase-1 (PFK1)?
✔✔The phosphorylation and inactivation of E1 subunit of PDC (pyruvate
dehydrogenase complex) - ✔✔Pyruvate dehydrogenase kinase catalyzes a reaction
that results in which of the following?
✔✔Pyruvate dehydrogenase complex; pyruvate - ✔✔Which of the following enzymes is
correctly paired with its activator?
✔✔Aconitase - ✔✔A farmer finds a cow dead in his field and notices an unusual plant
nearby. Autopsy results show an elevated level of citrate present in the cow's
, mitochondria. This data collectively suggest inhibition of which of the following
enzymes?
✔✔Succinate thiokinase - ✔✔A 10-year-old girl is swimming in a local competition. The
intense exercise will increase intracellular calcium levels which in turn will increase flux
through the TCA cycle by stimulating the activity of all of the following enzymes
EXCEPT?
✔✔Alanine - ✔✔Glycolysis provides intermediates that can be used to make other
necessary substrates. One example of this is the direct conversion of pyruvate to which
of the following amino acids?
✔✔Pyruvate - ✔✔Pyruvate dehydrogenase complex is highly regulated. The enzyme
will be most active when which of the following compounds is high?
✔✔Increased activity of pyruvate kinase - ✔✔A newborn is determined to have
hyperinsulinemia. Which of the following is likely to occur as a result of this deficiency?
✔✔Electrons are directly transferred from glycerol 3-phosphate to an FAD containing
glycerol phosphate dehydrogenase - ✔✔The glycerophosphate shuttle is the major
shuttle of most tissues. Which of the following best describes the transfer of electrons
by this shuttle?
✔✔Two electrons and two protons - ✔✔The fully reduced quinol form of CoQ contains
which of the following combinations of electrons and protons?
✔✔-3 - ✔✔A series of reactions have the following ΔG. A + B --> C ΔG = -1 C + D --> E
ΔG = +3 E + F --> G ΔG = -5 The overall ΔG for this series of reactions is determined to
be which of the following values?
✔✔The pH is higher in the matrix when compared to the intermembrane space. - ✔✔As
electrons flow through complexes in the inner mitochondrial membrane, protons are
pumped from the matrix to the intermembrane space. Which of the following statements
is most reflective of the pH in the intermembrane space?
✔✔NADH → complex I → CoQ → complex III → cyt c → complex IV - ✔✔Which of the
following describes a correct and complete electron transfer pathway necessary for
oxidative phosphorylation?
✔✔Pump protons from the mitochondrial matrix to the intermembrane space -
✔✔Complex II (Succinate Q-reductase) is not considered to be part of the process of
oxidative phosphorylation because it is unable to do which of the following activities?
