1|Page
UNE Medical Biochemistry Midterm Exam|| QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+||NEWEST EXAM!!!
An 18-month old is newly diagnosed with hereditary fructose
intolerance (deficiency of Aldolase B). His mother reports he is
particularly upset when he gets up in the morning or if he has
not eaten in a while. Laboratory testing showed low blood
glucose levels at the time of presentation. This presentation is
likely due to an accumulation of fructose-1-phosphate and
inhibition of which of the following pathways? - ANSWER-
Gluconeogenesis and glycogenolysis
Which of the following enzymes is involved in the non-oxidative
portion of the Pentose Pathway? - ANSWER-Transaldolase
In the red blood cell, glucose can be oxidized to two primary
products. One of the oxidation products is lactate and the other
is which of the following compounds? - ANSWER-Ribulose 5-
phosphate
Hereditary Fructose Intolerance (HFI) is a rare recessive
disorder. Which of the following is not a consequence of this
,2|Page
enzyme deficiency? - ANSWER-inability to metabolize glucose in
skeletal muscle
Galactose 1-phosphate is initially converted to glucose 1-
phosphate and requires which of the following compounds? -
ANSWER-UDP-glucose
Red blood cells lack mitochondria therefore glucose is primarily
oxidized to ribose and which of the following compounds? -
ANSWER-Lactate
A deficiency in glucose 6-phosphate dehydrogenase reduces the
levels of NADPH in the red blood cell. This leads to an increase
in which of the following compounds with the cell? - ANSWER-
Oxidized glutathione
The mechanism of action of the Pyruvate Dehydrogenase
Complex (PDC) relies on the use of three prosthetic groups in
the enzyme active site. Which of the following cofactors is not
required for the activity of the PDC? - ANSWER-Cobalamin
A 10-year old male is playing soccer and is sprinting after the
ball. Under these anaerobic conditions glucose is primarily
,3|Page
oxidized to which of the following compounds? - ANSWER-
Lactate
A 2-day old newborn is diagnosed with congenital lactic acidosis
because of a defective electron transport protein. This
deficiency leads to a decrease in the rate at which NADH and
FADH2 can be oxidized to produce ATP using oxidative
phosphorylation. As a result of an increase in cytosolic AMP
which glycolytic enzyme would be stimulated? - ANSWER-
Phosphofructokinase 1
Which of the following TCA cycle enzymes is responsible for the
reduction of FAD rather than NAD+? - ANSWER-Succinate
dehydrogenase
When insulin is elevated, the activity of phosphofructokinase 1
(PFK1) is stimulated by which of the following compounds? -
ANSWER-Fructose 2,6-biphosphate
Steroid hormones bind which of the following types of
receptors? - ANSWER-Intracellular receptors
, 4|Page
Which of the following is true of the fasted state? - ANSWER-
Muscle tissue preferentially takes up and oxidizes fatty acids for
fuel
Shortly after a meal, there will be increased activity in which of
the following pathways as a result of increased insulin? -
ANSWER-Glycolysis
Order the following statements to illustrate the correct cascade
of events that occurs after ligand binding of G-protein coupled
receptor (hetahelical receptor)
1. Degradation of cAMP by phosphdieterase
2. Dissociation of Gbeta and Gy subunits
3. G protein exchanges GDP for GTP in the G-alphas subunit
4. Activation of adenylyl cyclase (effector E) to generate cAMP -
ANSWER-3,2,4,1
A suspected mutation in the cortisol receptor is discovered.
Cortisol can still bind its receptor but the dimerized complex
remains in the cytosol. Based on this description which region
on the receptor is likely impacted? - ANSWER-Nuclear
localization signal
UNE Medical Biochemistry Midterm Exam|| QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+||NEWEST EXAM!!!
An 18-month old is newly diagnosed with hereditary fructose
intolerance (deficiency of Aldolase B). His mother reports he is
particularly upset when he gets up in the morning or if he has
not eaten in a while. Laboratory testing showed low blood
glucose levels at the time of presentation. This presentation is
likely due to an accumulation of fructose-1-phosphate and
inhibition of which of the following pathways? - ANSWER-
Gluconeogenesis and glycogenolysis
Which of the following enzymes is involved in the non-oxidative
portion of the Pentose Pathway? - ANSWER-Transaldolase
In the red blood cell, glucose can be oxidized to two primary
products. One of the oxidation products is lactate and the other
is which of the following compounds? - ANSWER-Ribulose 5-
phosphate
Hereditary Fructose Intolerance (HFI) is a rare recessive
disorder. Which of the following is not a consequence of this
,2|Page
enzyme deficiency? - ANSWER-inability to metabolize glucose in
skeletal muscle
Galactose 1-phosphate is initially converted to glucose 1-
phosphate and requires which of the following compounds? -
ANSWER-UDP-glucose
Red blood cells lack mitochondria therefore glucose is primarily
oxidized to ribose and which of the following compounds? -
ANSWER-Lactate
A deficiency in glucose 6-phosphate dehydrogenase reduces the
levels of NADPH in the red blood cell. This leads to an increase
in which of the following compounds with the cell? - ANSWER-
Oxidized glutathione
The mechanism of action of the Pyruvate Dehydrogenase
Complex (PDC) relies on the use of three prosthetic groups in
the enzyme active site. Which of the following cofactors is not
required for the activity of the PDC? - ANSWER-Cobalamin
A 10-year old male is playing soccer and is sprinting after the
ball. Under these anaerobic conditions glucose is primarily
,3|Page
oxidized to which of the following compounds? - ANSWER-
Lactate
A 2-day old newborn is diagnosed with congenital lactic acidosis
because of a defective electron transport protein. This
deficiency leads to a decrease in the rate at which NADH and
FADH2 can be oxidized to produce ATP using oxidative
phosphorylation. As a result of an increase in cytosolic AMP
which glycolytic enzyme would be stimulated? - ANSWER-
Phosphofructokinase 1
Which of the following TCA cycle enzymes is responsible for the
reduction of FAD rather than NAD+? - ANSWER-Succinate
dehydrogenase
When insulin is elevated, the activity of phosphofructokinase 1
(PFK1) is stimulated by which of the following compounds? -
ANSWER-Fructose 2,6-biphosphate
Steroid hormones bind which of the following types of
receptors? - ANSWER-Intracellular receptors
, 4|Page
Which of the following is true of the fasted state? - ANSWER-
Muscle tissue preferentially takes up and oxidizes fatty acids for
fuel
Shortly after a meal, there will be increased activity in which of
the following pathways as a result of increased insulin? -
ANSWER-Glycolysis
Order the following statements to illustrate the correct cascade
of events that occurs after ligand binding of G-protein coupled
receptor (hetahelical receptor)
1. Degradation of cAMP by phosphdieterase
2. Dissociation of Gbeta and Gy subunits
3. G protein exchanges GDP for GTP in the G-alphas subunit
4. Activation of adenylyl cyclase (effector E) to generate cAMP -
ANSWER-3,2,4,1
A suspected mutation in the cortisol receptor is discovered.
Cortisol can still bind its receptor but the dimerized complex
remains in the cytosol. Based on this description which region
on the receptor is likely impacted? - ANSWER-Nuclear
localization signal
