UNE MEDICAL BIOCHEMISTRY UNIT 3 | QUESTIONS AND ANSWERS |
VERIFIED AND WELL DETAILED ANSWERS | LATEST EXAM UPDATE
An 11-year-old girl is brought to the emergency department by her father. He
reports she has recently been very thirsty and needing to make frequent trips to the
bathroom. At her soccer game today, she complained of lightheadedness and that
the symptoms did not resolve even after drinking a power beverage. A rapid
dipstick test revealed glucose in her urine and further diagnostics are consistent
with a diagnosis of type 1 diabetes. Evaluation of this girl's liver would reveal an
increased rate of which of the following processes? - CORRECT ANSWER -
Ketogenesis
Which of the following lipoproteins distributes dietary lipids? - CORRECT
ANSWER - chylomicron
In the fasted state, fatty acyl-CoA are transported across the mitochondrial
membrane. The transport of fatty acids via carnitine palmitoyl transferase I (CPTI)
can be directly inhibited by which of the following compounds?
a. Malonyl CoA
b. Carnitine
c. Acetyl CoA
d. Palmitate - CORRECT ANSWER - Malonyl CoA
what is the role of adipose in metabolism - CORRECT ANSWER - storage of
TAG
The interaction of chylomicrons with lipoprotein lipase is stimulated by which of
the following Apo proteins? - CORRECT ANSWER - ApoC II
,Under fasting conditions (ratio of insulin to glucagon <1), elevated glucagon will
activate which of the following enzymes?
a. glycogen synthase
b. lipoprotein lipase
c. hormone sensitive lipase
d. pyruvate dehydrogenase complex - CORRECT ANSWER - hormone sensitive
lipase
A 5-year-old female is brought to the emergency department by her mother. She is
a type 1 diabetic and has not taken her insulin while away at a day camp. The child
is unresponsive. Which of the following enzymes is phosphorylated and active
under these conditions? - CORRECT ANSWER - Hormone Sensitive lipase
Nascent chylomicrons are synthesized in which tissue? - CORRECT ANSWER -
Intestine
ATP can be generated by many metabolic pathways in the body. Which of the
following processes generates the most ATP?
a. glycogenolysis
b. fatty acid β-oxidation
c. pentose phosphate pathway
d. citric acid cycle - CORRECT ANSWER - Fatty acid β-oxidation
During the fasted state, lipolysis is facilitated by the action of hormone sensitive
lipase. This enzyme requires which of the following modifications for activation? -
CORRECT ANSWER - Phosphorylation
,Bile salts are synthesized from cholesterol and are used for the emulsification of
dietary lipids. What is the primary fate of bile salts during digestion? - CORRECT
ANSWER - They are reabsorbed in the ileum
In liver, which of the following key inhibitory events ensures that newly
synthesized palmitoyl-CoA is not immediately oxidized?
a. Inhibition of CPT-II by acetyl-CoA
b. Inhibition of CPT-I by malonyl-CoA
c. Inhibition of CPT-I by palmitoyl-carnitine
d. Inhibition of acyl-CoA synthetase by malonyl-CoA - CORRECT ANSWER -
Inhibition of CPT-I by malonyl-CoA
Ketonuria, hyperglycemia and severe acidosis are prime diagnostic indicators of
the presentation of Type I diabetic ketoacidosis. Which of the following
compounds are "ketone bodies" that would be elevated in serum and urine of a
patient in this condition?
a. fumarate and succinate
b. pyruvate and lactate
c. acetone and ethanol
d. D-3-hydroxybutyrate and acetoacetate
e. oxaloacetate and pyruvate - CORRECT ANSWER - D-3-hydroxybutyrate and
acetoacetate
Nascent chylomicrons interact with HDL particles and obtain which of the
following Apo protiens? - CORRECT ANSWER - ApoCII and ApoE
, A well, 2-year-old girl contracted a vi ral i l lness at day care with vomiting,
diarrhea, and progressive lethargy. She presents to the cl inic with disorientation, a
barely rousable sensorium, cracked l ips, sunken eyes, lack of tears, flaccid skin
with "tenting" weak pulse with low blood pressure, and increased deep tendon
reflexes. Laboratory tests show low blood glucose, normal electrolytes, elevated l
iver enzymes, and (on chest X-ray) a dilated heart. Urinalysis reveals no infection
and no ketones. The child i s hospitalized and stabilized with 10% glucose
infusion. Admission laboratories show elevated medium-chain fatty acylcarnitines
in blood and 6-8 carbon dicarboxylic acids in the urine. Which of the following
abnormalities i s the most l ikely diagnosis in this child? - CORRECT ANSWER
- Defect of medium-chain coenzyme A deydrogenase
An individual is on a hunger strike and has not eaten in 13 days. Which of the
following best describes their metabolic state? - CORRECT ANSWER - The
brain will be preferentially oxidizing ketones.
The activity of pancreatic lipase is inhibited by which of the following
compounds? - CORRECT ANSWER - Bile salts
Which of the following is NOT a product of β-oxidation?
a. NADH
b. FADH2
c. NADPH
d. Acetyl-CoA - CORRECT ANSWER - NADPH
Under fasting conditions (ratio of insulin to glucagon <1), elevated glucagon will
activate which of the following enzymes? - CORRECT ANSWER - Hormone
sensitive lipase
VERIFIED AND WELL DETAILED ANSWERS | LATEST EXAM UPDATE
An 11-year-old girl is brought to the emergency department by her father. He
reports she has recently been very thirsty and needing to make frequent trips to the
bathroom. At her soccer game today, she complained of lightheadedness and that
the symptoms did not resolve even after drinking a power beverage. A rapid
dipstick test revealed glucose in her urine and further diagnostics are consistent
with a diagnosis of type 1 diabetes. Evaluation of this girl's liver would reveal an
increased rate of which of the following processes? - CORRECT ANSWER -
Ketogenesis
Which of the following lipoproteins distributes dietary lipids? - CORRECT
ANSWER - chylomicron
In the fasted state, fatty acyl-CoA are transported across the mitochondrial
membrane. The transport of fatty acids via carnitine palmitoyl transferase I (CPTI)
can be directly inhibited by which of the following compounds?
a. Malonyl CoA
b. Carnitine
c. Acetyl CoA
d. Palmitate - CORRECT ANSWER - Malonyl CoA
what is the role of adipose in metabolism - CORRECT ANSWER - storage of
TAG
The interaction of chylomicrons with lipoprotein lipase is stimulated by which of
the following Apo proteins? - CORRECT ANSWER - ApoC II
,Under fasting conditions (ratio of insulin to glucagon <1), elevated glucagon will
activate which of the following enzymes?
a. glycogen synthase
b. lipoprotein lipase
c. hormone sensitive lipase
d. pyruvate dehydrogenase complex - CORRECT ANSWER - hormone sensitive
lipase
A 5-year-old female is brought to the emergency department by her mother. She is
a type 1 diabetic and has not taken her insulin while away at a day camp. The child
is unresponsive. Which of the following enzymes is phosphorylated and active
under these conditions? - CORRECT ANSWER - Hormone Sensitive lipase
Nascent chylomicrons are synthesized in which tissue? - CORRECT ANSWER -
Intestine
ATP can be generated by many metabolic pathways in the body. Which of the
following processes generates the most ATP?
a. glycogenolysis
b. fatty acid β-oxidation
c. pentose phosphate pathway
d. citric acid cycle - CORRECT ANSWER - Fatty acid β-oxidation
During the fasted state, lipolysis is facilitated by the action of hormone sensitive
lipase. This enzyme requires which of the following modifications for activation? -
CORRECT ANSWER - Phosphorylation
,Bile salts are synthesized from cholesterol and are used for the emulsification of
dietary lipids. What is the primary fate of bile salts during digestion? - CORRECT
ANSWER - They are reabsorbed in the ileum
In liver, which of the following key inhibitory events ensures that newly
synthesized palmitoyl-CoA is not immediately oxidized?
a. Inhibition of CPT-II by acetyl-CoA
b. Inhibition of CPT-I by malonyl-CoA
c. Inhibition of CPT-I by palmitoyl-carnitine
d. Inhibition of acyl-CoA synthetase by malonyl-CoA - CORRECT ANSWER -
Inhibition of CPT-I by malonyl-CoA
Ketonuria, hyperglycemia and severe acidosis are prime diagnostic indicators of
the presentation of Type I diabetic ketoacidosis. Which of the following
compounds are "ketone bodies" that would be elevated in serum and urine of a
patient in this condition?
a. fumarate and succinate
b. pyruvate and lactate
c. acetone and ethanol
d. D-3-hydroxybutyrate and acetoacetate
e. oxaloacetate and pyruvate - CORRECT ANSWER - D-3-hydroxybutyrate and
acetoacetate
Nascent chylomicrons interact with HDL particles and obtain which of the
following Apo protiens? - CORRECT ANSWER - ApoCII and ApoE
, A well, 2-year-old girl contracted a vi ral i l lness at day care with vomiting,
diarrhea, and progressive lethargy. She presents to the cl inic with disorientation, a
barely rousable sensorium, cracked l ips, sunken eyes, lack of tears, flaccid skin
with "tenting" weak pulse with low blood pressure, and increased deep tendon
reflexes. Laboratory tests show low blood glucose, normal electrolytes, elevated l
iver enzymes, and (on chest X-ray) a dilated heart. Urinalysis reveals no infection
and no ketones. The child i s hospitalized and stabilized with 10% glucose
infusion. Admission laboratories show elevated medium-chain fatty acylcarnitines
in blood and 6-8 carbon dicarboxylic acids in the urine. Which of the following
abnormalities i s the most l ikely diagnosis in this child? - CORRECT ANSWER
- Defect of medium-chain coenzyme A deydrogenase
An individual is on a hunger strike and has not eaten in 13 days. Which of the
following best describes their metabolic state? - CORRECT ANSWER - The
brain will be preferentially oxidizing ketones.
The activity of pancreatic lipase is inhibited by which of the following
compounds? - CORRECT ANSWER - Bile salts
Which of the following is NOT a product of β-oxidation?
a. NADH
b. FADH2
c. NADPH
d. Acetyl-CoA - CORRECT ANSWER - NADPH
Under fasting conditions (ratio of insulin to glucagon <1), elevated glucagon will
activate which of the following enzymes? - CORRECT ANSWER - Hormone
sensitive lipase
