Deck 22: Mammalian Fuel Metabolism: Integration and Regulation

Question 1

Matching
Choose the correct answer from the list. Not all the answers will be used.
The ____ provides a pathway for the metabolic use of lactate for production of glucose.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Answer 1

Cori cycle

Question 2

Matching
Choose the correct answer from the list. Not all the answers will be used.
The ______ stores very little glycogen and therefore requires a steady supply of glucose from the blood.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Answer 2

brain

Question 3

Animals lack the ability to produce glucose from ______.

A)other sugars
B)fatty acids
C)pyruvate
D)amino acids
E)starches

Answer 3

fatty acids

Question 4

Phospholipase C cleaves PIP₂, generating

A)IP₃ and DAG (inositol-1,4,5-trisphosphate and 1,2-diacylglycerol).
B)cAMP and PP_i.
C)cAMP and DAG (1,2-diacylglycerol).
D)IP₃ and PP_i.
E)IP₃ and P_i.

Question 5

Matching
Choose the correct answer from the list. Not all the answers will be used.
During starvation the _____ generate as much as 50% of the body's glucose supply.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Question 6

Matching
Choose the correct answer from the list. Not all the answers will be used.
Epinephrine binding to the ______ causes an increase in intracellular [Ca²⁺].

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Question 7

The common products of fuel metabolism in mammals are

A)oxaloacetate and acetyl- CoA.
B)pyruvate and acetyl-CoA.
C)ATP and acetyl-CoA.
D)pyruvate and glucose.
E)none of the above

Question 8

Matching
Choose the correct answer from the list. Not all the answers will be used.
Mice lacking the protein ______ are genetically obese.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Question 9

Which of the following mechanisms for ATP regeneration are listed in order utilized?

A)glycolysis, phosphocreatine, oxidative phosphorylation
B)phosphocreatine, glycolysis, oxidative phosphorylation
C)phosphocreatine, oxidative phosphorylation, glycolysis,
D)phosphocreatine, oxidative phosphorylation, glycolysis, gluconeogenesis
E)none of the above

Question 10

Matching
Choose the correct answer from the list. Not all the answers will be used.
The activity of the _____ enzyme glucokinase increases with high blood glucose.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Question 11

Matching
Choose the correct answer from the list. Not all the answers will be used.
Following prolonged starvation, ______ are used as fuel by the brain.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Question 12

The glucose transporter in muscle cells is

A)insulin.
B)glucagon.
C)GLUT2.
D)GLUT4.
E)none of the above

Question 13

Matching
Choose the correct answer from the list. Not all the answers will be used.
______ is the degradation product of glucose, fatty acids, and ketogenic amino acids.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Question 14

Which of the following reactions is catalyzed by adenylate cyclase?

A)ATP $\rarr$ cAMP + PP_i
B)cAMP $\rarr$ AMP
C)ATP $\rarr$ cATP
D)ADP $\rarr$ cAMP + P_i
E)AMP $\rarr$ cAMP

Question 15

Matching
Choose the correct answer from the list. Not all the answers will be used.
The endocrine glands secrete ______ which result in numerous cellular responses.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Question 16

Glucose is the preferred fuel of muscles because

A)it can be metabolized under anaerobic conditions.
B)it can be generated from ketone bodies even during starvation.
C)the heart muscle uses glucose exclusively as a fuel.
D)it is the most efficient energy storage available.
E)all of the above

Question 17

The metabolic fate(s)of glucose-6-phosphate include
I.glycogen and glucose.
II.ribose-5-phosphate
III.acetyl-CoA.
IV.DNA and RNA.

A)I
B)I, II
C)I, III
D)III, IV
E)I, II, III, IV

Question 18

Matching
Choose the correct answer from the list. Not all the answers will be used.
______ and other waste products from the blood are excreted by the kidney.

A)α-adrenergic receptor
B)β-adrenergic receptor
C)Cori cycle
D)urea cycle
E)leptin
F)phosphatase
G)liver
H)hormones
I)acetyl CoA
J)ketone bodies
K)urea
L)kidney
M)brain
N)pancreas

Question 19

A balanced meal containing fatty acids, carbohydrates, and protein is digested.Which of the following is TRUE?
I.Carbohydrates are absorbed by the stomach and delivered to the liver.
II.Fatty acids are absorbed by the intestinal mucosa and circulated through the lymph.
III.Proteins are digested into monomer amino acids and absorbed by the intestinal mucosa after which the majority is delivered to the liver.

A)I, II, III
B)I, II
C)II, III
D)I, III
E)III only

Question 20

Glucokinase is regulated by _______ and _____.

A)glucokinase regulatory protein, fructose-6-phosphate
B)fructose-6-phosphate, glucose
C)glucose-6-phosphate; glucose
D)ATP; glucose-6-phosphate
E)all of the above

Question 21

The interorgan pathway that allows transport of nitrogen from muscle to the liver utilizes ____ as an amino group acceptor in the transamination reaction generating _____.

A)acetyl-CoA; alanine
B)acetyl-CoA; glutamine
C)pyruvate; glutamine
D)pyruvate; glutamate
E)pyruvate; alanine

Question 22

Aerobic activity in response to stress results in which of the following?
I.Glycolysis occurs in the muscle.
II.Glycolysis occurs in the liver.
III.Glycogenolysis occurs in the muscle.
IV.Glycogenolysis occurs in the liver.

A)I, III, IV
B)I, II, IV
C)II, IV
D)II, IV
E)III, IV

Question 23

Which of the following statements is TRUE regarding the blood glucose level of non-insulin dependent diabetics tend to compare to that of normal individuals?

A)Blood glucose levels of diabetics tend to be very stable, but at a higher level.
B)Blood glucose levels of diabetics tend to be variable and higher.
C)Blood glucose levels decrease more rapidly following a meal, often dropping lower than is tolerable.
D)Blood glucose levels average the same level in diabetics, but reach higher peaks for short periods.
E)none of the above

Question 24

Which of the following can generate glucose?
I.kidney
II.liver
III.adipose tissue
IV.muscle

A)I, II, III, IV
B)I, II, IV
C)I, II
D)II, IV
E)II only

Question 25

At low glucose concentrations (≤5mM), the majority of glucose produced by liver cells is due to the action of

A)glucokinase.
B)hexokinase.
C)glucose-6-phosphatase.
D)AMP-dependent protein kinase (AMPK).
E)AMP-responsive tyrosine kinase.

Question 26

Which of the following occurs during starvation?
I.The kidney generates approximately half the glucose required for the body.
II.The brain utilizes ketone bodies as a fuel source.
III.The adipose tissue releases fatty acids.
IV.Gluconeogenesis occurs in the liver.

A)I, II, III, IV
B)I, II, III
C)I, II
D)II, III
E)II, III, IV

Question 27

Based on the information given in the chapter complete the following statement about the graph shown below: The curve labeled ___ corresponds to activity of glucokinase under conditions with no inhibition.The binding of ____ to the regulating protein would result in kinetic behavior represented by curve ____.

A)B; F6P; A
B)A; glucose; B
C)B; F6P; C
D)C; F6P; B
E)B; glucose; C

Question 28

Adipose tissue

A)secretes hormones that regulate metabolism.
B)synthesizes both glucose and triacylglycerols.
C)contains enough stored energy to survive about one month.
D)A and B
E)A and C

Question 29

Which of the following best describes the function of AMP-dependent protein kinase (AMPK)?

A)It activates ATP-generating metabolic pathways and inhibits biosynthetic pathways.
B)It activates biosynthetic pathways and inhibits ATP-generating metabolic pathways.
C)It activates both ATP-generating and biosynthetic pathways.
D)It inhibits both ATP-generating and biosynthetic pathways.
E)None of the above is correct.

Question 30

Excess glucosylation of lens proteins in diabetics leads to

A)cataracts.
B)retinal degeneration.
C)glaucoma.
D)ketosis.
E)fatty liver disease.

Question 31

Synthesis of triacylglycerols is dependent on

A)the availability of glycerol-3-phosphate.
B)the uptake of glucose from the bloodstream.
C)the enzyme responsible for reduction of dihydroxyacetone phosphate.
D)the circulation of lipoprotein.
E)all of the above

Question 32

In an average individual the liver glycogen is depleted during starvation in approximately

A)45-60 minutes.
B)4-6 hours.
C)18-24 hours.
D)55-60 hours.
E)5-7 days.

Question 33

Which of the following are effects of insulin secretion?
I.Muscle and adipose tissue are stimulated to take up glucose.
II.Glycogen synthesis increases in the liver.
III.Gluconeogenesis is inhibited in the liver and kidney.
IV.Lipolysis increases in the adipose tissue.

A)I, II
B)I
C)I, II, III
D)I, III
E)II, IV

Question 34

Which of the following proteins stimulates the appetite?

A)leptin
B)ghrelin
C)adiponectin
D)insulin
E)( PYY_3-36)

Question 35

The majority of glucose in the brain

A)is used to store adequate glycogen for extended periods of starvation.
B)is used to produce ATP for membrane Na⁺-K⁺ ATPase required for nerve impulse transmission.
C)is synthesized from fatty acids due to the need for high ATP levels.
D)is synthesized in the adipose tissue and transported to the brain.
E)is synthesized from ketone bodies under conditions of prolonged fasting.

Question 36

Insulin-dependent (type 1)diabetes

A)is associated with a deficiency of pancreatic β-cells.
B)is associated with a deficiency of insulin receptors.
C)is associated with a deficiency of signal transduction
D)can be treated with injections of leptin.
E)can be treated with injections of ghrelin.

Question 37

Which of the following metabolizes ketone bodies?
I.brain
II.liver
III.muscle
IV.adipose tissue

A)I, II, III, IV
B)I, II, III
C)I, III
D)II only
E)III only

Question 38

Which of the following is FALSE relating to leptin?

A)Obese mice lacking leptin tend to overeat.
B)Leptin seems to function by different mechanisms in mice and humans.
C)Obesity in humans leads to a decrease in leptin production.
D)Obesity leads to leptin resistance.
E)none of the above

Question 39

Which of the following is TRUE regarding pancreatic $\beta$ cells?

A)Insulin is secreted by the $\beta$ cells in response to the increase in $\beta$ cell glucose receptor binding.
B)Glucagon is secreted by the $\beta$ cells in response to the increase in $\beta$ cell glucose receptor binding.
C)Insulin is secreted by the $\beta$ cells in response to high glucose levels.
D)Insulin is secreted by the $\beta$ cells in response to low glucose levels.
E)Glucagon is secreted by the $\beta$ cells in response to high glucose levels.

Question 40

Which of the following statements concerning the response of hepatocytes to insulin is FALSE?

A)Phosphorylase kinase is inactivated, decreasing glycogenolysis.
B)Glycogen synthase is activated.
C)Transcription of glucokinase increases.
D)Glucose uptake is increased in the liver.
E)The liver stores glucose as glycogen or triacylglycerols.

Question 41

Type 2 diabetes
I.can develop due to a mutation in the insulin receptor
II.can develop in individuals with insulin resistance.
III.results in hypersensitivity to insulin release.
IV.are treated with drugs that decrease AMPK activity.

A)I, II, IV
B)I, II
C)II, IV
D)III, IV
E)I, IV

Question 42

Metabolism in the muscle is controlled hormonally by

A)glucagon
B)insulin
C)epinephrine
D)B and C
E)A, B, C

Question 43

Metformin and thiazolidinediones (TZDs)are used to treat ____ and produce a(an)______ in AMPK activity.

A)type 2 diabetes; decrease
B)type 2 diabetes; increase
C)type 1 diabetes; decrease
D)type 1 diabetes; increase
E)both type 1 and type 2 diabetes; decrease

Question 44

Evidence suggests that the lifespan of a rodent may be extended

A)30% by a 60% reduction in calorie intake.
B)50% by a 30-40% reduction in calorie intake.
C)40% by a 50% reduction in calorie intake.
D)50% by reducing caloric intake by half.
E)50% by minimizing carbohydrate rich calorie sources.

Question 45

The muscle and liver

A)both increase glucose uptake in response to insulin.
B)both increase glycogenolysis in response to glucagon.
C)both increase glycogenolysis in response to insulin.
D)both decrease gluconeogenesis in response to insulin.
E)none of the above

Question 46

Which of the following are characteristics of metabolic syndrome?
I.insulin resistance
II.inflammation
III.increased risk for type 1 diabetes.
IV.hypersensitivity to insulin

A)I, II
B)I, II, III
C)I, II, III, IV
D)I, III
E)I only

Question 47

Activation of AMPK activity is

A)accomplished by AMP induced conformational changes facilitating phosphorylation.
B)accomplished by ATP induced conformational change facilitating phosphorylation.
C)inhibited by high levels of AMP due to conformational changes burying the phosphorylation site.
D)increased by high levels of ATP due to conformational changes burying the phosphorylation site.
E)none of the above

Question 48

During prolonged starvation the majority of the stored caloric energy comes from fat stores.Which of the following provides the second largest caloric energy total?

A)muscle glycogen
B)liver glycogen
C)blood glucose
D)muscle protein
E)All are approximately equal.

Question 49

Which of the following is part of the regulation of metabolism?

A)receptor tyrosine kinase
B)adenylate cyclase
C)phosphoinositide pathway
D)all of the above
E)none of the above

Question 50

Glucose uptake

A)in the liver is mediated by GLUT4.
B)in the muscle is increased in response to insulin due to increased expression of GLUT4.
C)in the brain is adjusted relative to the concentration of glucose.
D)A and B
E)A, B, C