Deck 17: Interorgan and Intracellular Coordination of Energy Metabolism in Vertebrates

Question 1

Calculate the approximate weight gain per annum if energy intake exceeds energy expenditure by 5 g (1 teaspoon) of sugar per day. Assume that 120 g sugar yields ~1760 kJ of energy and adipose tissue contains ~30 MJkg-1.

Answer 1

0.89 kg

Question 2

The main organ that monitors and stabilizes blood glucose is the ________.

Answer 2

liver

Question 3

Sirtuins are deacetylases that are ________-dependent and therefore can respond to the redox state of the cell.

Answer 3

NAD+

Question 4

Epinephrine has a longer term effect on metabolism than does glucagon.

Question 5

A side effect of diabetes is the production of acetone from the decarboxylation of acetoacetate due to ketoacidosis.

Question 6

One of the metabolic adaptations that occurs with prolonged starvation is the increased production of ________ because there is insufficient oxaloacetate for oxidation of all the acetyl CoA produced from fat breakdown.

Question 7

Which of the following statements is FALSE?

A) Glucagon increases cAMP levels in the liver in response to the fasting state.
B) Epinephrine causes mobilization of triacylglycerols from adipose tissue in response to stress.
C) Insulin decreases gluconeogenesis in the liver and increases glucose uptake and glycolysis in muscle.
D) Glycogen phosphorylase is an enzyme target of insulin but not of glucagon.
E) Phosphofructokinase-1 is an enzyme target of glucagon.

Question 8

Which of the following is an endocrine regulator that inhibits food intake?

A) Ghrelin
B) Adiponectin
C) Leptin
D) Insulin
E) Both C and D

Question 9

AMPK and mTOR play opposing roles in regulating metabolic activity in response to energy status.

Question 10

Which of the following organs both uses and exports fatty acids as a fuel source?

A) Resting skeletal muscle
B) Liver
C) Adipose tissue
D) Heart muscle
E) B and C

Question 11

Which of the following fuel reserves can be used by skeletal muscle?

A) Protein
B) Glycogen
C) Creatine phosphate
D) Fatty acids
E) All of the above

Question 12

Insulin and glucagon are both synthesized by the same cell types in the pancreas.

Question 13

The primary factor that controls metabolism is:

A) post-translational modification of enzymes.
B) substrate availability.
C) enzyme turnover.
D) hormone signaling.
E) compartmentalization of metabolic pathways.

Question 14

The heart is a completely aerobic tissue that can make use of fatty acids, lactate, glucose and ketone bodies as fuel sources.

Question 15

Which of the following is NOT an effect of glucagon?

A) Hydrolysis of fructose-2,6-bisphosphate
B) Inhibition of glycogenolysis
C) Inhibition of pyruvate kinase
D) Phosphorylation of hormone-sensitive lipase
E) Phosphorylation of glycogen synthase