UNE Medical Biochemistry Midterm Review Questions &
Answers Rated 100% Correct!!
Ribose and NADPH
A family presents for genetic counseling. The couple has two female children who are
alive and well; however, their infant son recently died in the nursery with severe
hemolysis (lysis of red blood cells) and jaundice. The wife recalls she lost a brother in
infancy with severe hemolysis, induced after a viral infection. The physician suspects a
glucose-6-phosphate dehydrogenase deficiency, this would result in a deficiency in
which of the following compounds in red blood cells?
Transketolase
A patient presents to the emergency department with lactic acidosis. A deficiency in
thiamine (TPP) is suspected and this will be consistent with a decrease in the activity of
following enzymes?
UDP-Glucose
Galactose 1-phosphate is initially converted to glucose 1-phosphate and requires which
of the following compounds?
Thiamine diphosphate
Which of the following cofactors is required for transketolase activity?
Glyceraldehyde 3-phosphate
Aldolase B facilities a reaction that cleaves fructose 1-phosphate into two 3-carbon
molecules that will enter glycolysis as which of the following compounds?
Glycolysis
High levels of activity of the non-oxidative portion of the pentose phosphate pathway will
directly produce intermediates of which of the following pathways?
Glucose 6-phosphate dehydrogenase
The major regulatory step of the pentose phosphate pathway is catalyzed by which
enzyme?
VLDL particles
Insulin stimulates fatty acid synthesis in the liver. These fatty acids are transported to
the adipose tissue as which of the following?
Free fatty acids
A young woman goes to work without eating breakfast and skips lunch. In this scenario,
which of the following pathways is providing substrates used to generate ATP in the
liver?
Glucagon
Caffeine is a natural inhibitor of phosphodiesterase. If you were to consume a large
amount of coffee you would likely see a prolonged response to which of the following
stimulants or hormones?
They enhance transcription when bound to receptors
A teenage female presenting with lack of menstruation (amenorrhea) is found to have a
dysfunctional steroid receptor characteristic of androgen insensitivity syndrome. Which
of the following statements accurately describes steroid hormones?
Intracellular receptors
Steroid hormones bind which of the following types of receptors?
, They are specific to a chemical messenger
Which of the following is a characteristic of all receptors?
Free fatty acids
What is the primary oxidized fuel for skeletal muscle in the fasted state?
Cyclic-AMP response element binding protein (CREB)
cAMP elicits multiple cellular responses. The effects of cAMP on gene transcription are
directly mediated by which of the following DNA binding proteins?
GLUT4
An individual is recently diagnosed with Type 2 diabetes. In this individual,
hyperglycemia may in part be due to inactivity of which of the following glucose
transporters on skeletal muscle?
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
Answers Rated 100% Correct!!
Ribose and NADPH
A family presents for genetic counseling. The couple has two female children who are
alive and well; however, their infant son recently died in the nursery with severe
hemolysis (lysis of red blood cells) and jaundice. The wife recalls she lost a brother in
infancy with severe hemolysis, induced after a viral infection. The physician suspects a
glucose-6-phosphate dehydrogenase deficiency, this would result in a deficiency in
which of the following compounds in red blood cells?
Transketolase
A patient presents to the emergency department with lactic acidosis. A deficiency in
thiamine (TPP) is suspected and this will be consistent with a decrease in the activity of
following enzymes?
UDP-Glucose
Galactose 1-phosphate is initially converted to glucose 1-phosphate and requires which
of the following compounds?
Thiamine diphosphate
Which of the following cofactors is required for transketolase activity?
Glyceraldehyde 3-phosphate
Aldolase B facilities a reaction that cleaves fructose 1-phosphate into two 3-carbon
molecules that will enter glycolysis as which of the following compounds?
Glycolysis
High levels of activity of the non-oxidative portion of the pentose phosphate pathway will
directly produce intermediates of which of the following pathways?
Glucose 6-phosphate dehydrogenase
The major regulatory step of the pentose phosphate pathway is catalyzed by which
enzyme?
VLDL particles
Insulin stimulates fatty acid synthesis in the liver. These fatty acids are transported to
the adipose tissue as which of the following?
Free fatty acids
A young woman goes to work without eating breakfast and skips lunch. In this scenario,
which of the following pathways is providing substrates used to generate ATP in the
liver?
Glucagon
Caffeine is a natural inhibitor of phosphodiesterase. If you were to consume a large
amount of coffee you would likely see a prolonged response to which of the following
stimulants or hormones?
They enhance transcription when bound to receptors
A teenage female presenting with lack of menstruation (amenorrhea) is found to have a
dysfunctional steroid receptor characteristic of androgen insensitivity syndrome. Which
of the following statements accurately describes steroid hormones?
Intracellular receptors
Steroid hormones bind which of the following types of receptors?
, They are specific to a chemical messenger
Which of the following is a characteristic of all receptors?
Free fatty acids
What is the primary oxidized fuel for skeletal muscle in the fasted state?
Cyclic-AMP response element binding protein (CREB)
cAMP elicits multiple cellular responses. The effects of cAMP on gene transcription are
directly mediated by which of the following DNA binding proteins?
GLUT4
An individual is recently diagnosed with Type 2 diabetes. In this individual,
hyperglycemia may in part be due to inactivity of which of the following glucose
transporters on skeletal muscle?
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
