What are the main products of beta oxidation?
1 NADH, 1 FADH, 1 Acetyl CoA
So in the case of an 11-year-old girl brought to the emergency department by her
father, he's reporting that she's been very thirsty and needing to make frequent
strips to the bathroom. Today, she reported lightheadedness during a soccer
game and symptoms did not resolve after drinking a power beverage. A rapid
dipstick test revealed glucose in her urine and further diagnosis are consistent
with a diagnosis of type I diabetes. So evaluation of this girl's liver would reveal
an increased rate in which of the
following processes?
A. Fatty Acid Synthesis
B. Glycogenesis
C. Glycolysis
D. Ketogenesis
E. Protein Synthesis
D. Ketogenesis
A 5 year old female brought to the Emergency Department by her mother, and
she's a Type 1 diabetic and has not taken her insulin while she's been away, the
child is unresponsive, and we ask the question, which of the following enzymes
is phosphorylated and active under these conditions?
A. Acetyl- CoA Carboxylase
B. Hormone Sensitive Lipase
C. Glycogen Synthase
D. Phosphofructokinase 2
E. Pyruvate Kinase
B. Hormone Sensitive Lipase
An individual goes to bed around 8pm and doesn't wake up until 9am the next
morning. During this time, which of the following is the primary oxidizable
substrate in the skeletal muscle?
Free Fatty Acids
During the fasted state, lipolysis is facilitated by the action of hormone sensitive
lipase. This enzyme requires which of the following modifications for activation?
Phosphorylation
A well, 2-year-old girl presents to the clinic with symptoms of a viral illness. Her
parents report she has had bouts of vomiting and diarrhea over the last 24 hours.
This morning they could barely wake her from her crib and she was very weak.
Laboratory tests show low blood glucose (hypoglycemia) and elevated liver
enzymes. There are no ketones in her urine. The child is hospitalized and glucose
is administered by I.V. Additionally laboratory analysis showed elevated medium-
chain fatty acyl carnitines in blood and 6-8 carbon dicarboxylic acids in the urine.
What is her diagnosis?
defect of medium-chain coenzyme A dehydrogenase
Under fasting conditions (ratio of insulin to glucagon <1), elevated glucagon will
activate which of the following enzymes?
, Hormone Sensitive Lipase
Ketonuria, hyperglycemia and severe acidosis are prime diagnostic indicators of
the presentation of type 1 diabetic ketoacidosis. Which of the following
compounds are "ketone bodies" that would be elevated in serum and urine of a
patient in this condition?
D-3-hydroxybutyrate and acetoacetate
In liver, which of the following key inhibitory events ensures that newly
synthesized palmitoyl-CoA is not immediately oxidized?
Inhibition of acyl-CoA by malonyl-CoA
In the fasted state, fatty acyl-CoAs 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?
Malonyl-CoA
An individual is on a hunger strike and has not eaten in 13 days. Which of the
following best describes their metabolic state?
The brain will be preferentially oxidizing ketones
An increase in the ratio of insulin to glucagon will increase the activity of which
of the following enzymes (+ indicates activity is increased; - indicates activity is
not increased by insulin)?
1.Hormone sensitive lipase 2. Acetyl-CoA carboxylase 3. Phosphofructokinase-2
(PFK2)
4. Glycogen synthase
(-) hormone sensitive lipase
(+) acteyl- CoA Carboxylase
(+) phosphofructokinase -2
(+) Glycogen synthase
Fatty acid synthase is a multimeric enzyme complex. Which of the following
subunits contains pantothenic acid as a cofactor?
Acyl Carrier Protein (ACP)
Malate can be converted to pyruvate in the cytosol. Which of the following
compounds is directly generated in this conversion and is essential for fatty acid
synthesis?
NADPH
NADPH is essential for fatty acid synthesis and can be generated by which two
enzymes? (+ indicates NADPH can be produced by the enzyme; - indicates the
enzyme does not produce NAPDH)
1. Glucose 6-phosphate dehydrogenase
2. Malic enzyme
3. Pyruvate dehydrogenase complex
(+) Glucose 6-phosphate dehydrogenase
(+) Malic enzyme
(-) Pyruvate dehydrogenase complex
What is the regulatory enzyme for fatty acid synthesis?
Acetly-CoA Carboxylase
What is the regulated step of lipogenesis in eukaryotes?