Deck 46: Control of Energy Balance, Metabolic Rate, and Body Temperature

Question 1

Which of the following is a carbohydrate monomer absorbed from the digestive tract?

A) glycogen
B) starch
C) cellulose
D) glucose
E) lipoprotein

Answer 1

glucose

Question 2

Which of the following is NOT a fate of glucose entering the body during the absorptive state?

A) used as fuel immediately by body cells
B) stored as glycogen in the liver
C) stored as glycogen in muscles
D) converted to triglycerides and stored in fat cells
E) converted into the hard extracellular matrix of bone

Answer 2

converted into the hard extracellular matrix of bone

Question 3

Which of the following organs or tissues can ONLY use glucose as a source of energy?

A) heart
B) skeletal muscles like the bicep
C) brain
D) liver
E) spleen

Answer 3

brain

Question 4

Which of the following organs or tissues can use glycerol and fatty acids as energy sources during the postabsorptive period?

A) heart
B) skeletal muscles like the bicep
C) brain
D) heart and skeletal muscles
E) skeletal muscles and brain

Question 5

The primary precursor utilized in gluconeogenesis is

A) glycogen.
B) starch.
C) glycerol.
D) the amino acid glutamate.
E) the nucleic acid guanosine.

Question 6

Which of the following is NOT TRUE of the absorptive period?

A) Glucose absorption from the gut is high.
B) Glucose utilization by cells is high.
C) Fat utilization by cells is high.
D) Synthesis of triglycerides is high.
E) Breakdown of glycogen is low.

Question 7

The main DISADVANTAGE of excessive gluconeogenesis during prolonged postabsorptive periods is that

A) continued protein breakdown can impair enzymatic activity and plasma membrane functions.
B) carbohydrate buildup in the liver impairs its function.
C) the brain is exposed to levels of glucose that are too high.
D) tissues other than the brain increase glucose utilization.
E) glucose absorption from the gut is impaired.

Question 8

The phenomenon of "glucose sparing" depends most critically on

A) glycogenolysis.
B) protein synthesis.
C) lipolysis.
D) lipogenesis.
E) glucose polymer formation.

Question 9

Which of the following organs is responsible for the synthesis of ketones from fatty acids?

A) liver
B) stomach
C) heart
D) brain
E) kidney

Question 10

Which of the following is TRUE of the hormone glucagon?

A) It is synthesized in the pancreas.
B) It stimulates glycogenolysis by the liver.
C) It stimulates gluconeogenesis by the liver.
D) It is released in response to low blood glucose levels.
E) All of the answers provided are correct.

Question 11

Metabolic rate can be measured indirectly by measuring consumption of what substance?

A) water
B) carbon dioxide
C) oxygen
D) insulin
E) None of these answers are correct.

Question 12

Digesting food increases metabolic rate. Which type of nutrient produces the greatest increases?

A) simple carbohydrates
B) complex carbohydrates
C) fats
D) proteins
E) nucleic acids

Question 13

Which of the following statements concerning the relationship of energy expenditure to body size in animals is TRUE?

A) Large endotherms have higher mass-specific metabolic rates (O2/g tissue/hour) than small endotherms.
B) Large ectotherms have lower mass-specific metabolic rates than small ectotherms.
C) There is an inverse (i.e., negative) relationship between the TOTAL energy used by an animal and its body size.
D) Only endotherms show an inverse relationship between specific metabolic rate and body size.
E) Only ectotherms show an inverse relationship between specific metabolic rate and body size.

Question 14

Which of the following animals would you predict would have the highest mass-specific metabolic rate?

A) a lizard
B) a squid
C) an elephant
D) a goose
E) a hummingbird

Question 15

Hibernation in small mammals is an example of what specific phenomenon?

A) sleep
B) rest
C) torpor
D) hiding
E) activity

Question 16

Which hormone has potent, direct effects on appetite?

A) leptin
B) insulin
C) glucagon
D) thyroxine
E) vasopressin

Question 17

Increases in leptin levels will ____ appetite and _____ metabolic rate.

A) decrease, increase
B) decrease, decrease
C) increase, increase
D) increase, decrease
E) increase, not change

Question 18

Imagine you conduct a parabiosis experiment with two strains of mice, one of which lacks a functional leptin gene (ob strain) while the other lacks a functional receptor for this hormone (db strain). Which of the following outcomes would you observe?

A) no weight change in the ob mouse
B) no weight change in the db mouse
C) increased body weight in the ob mouse
D) decreased body weight in the ob mouse
E) decreased body weight in the db mouse

Question 19

Most important biochemical reactions in an animal's body are catalyzed by enzymes. For each increase in temperature of 10^oC, the rate of enzyme-catalyzed reactions

A) does not change.
B) slows down by approximately 90%.
C) slows down by approximately 50%.
D) increases in rate approximately 2-3 fold.
E) increases in rate by approximately 10 fold.

Question 20

Temperature is important for organisms because

A) it affects the rate of biochemical reactions.
B) it affects the fluidity and rigidity of plasma membranes.
C) high temperatures can damage enzymes.
D) it affects metabolic rates and energy expenditure.
E) All the choices for this question are correct.

Question 21

Most body heat in endotherms is derived from _____ while most body heat in ectotherms is derived from ____.

A) metabolic processes, metabolic processes
B) metabolic processes, their environment
C) their environment, metabolic processes
D) their environment, their environment
E) fur, insulating scales

Question 22

Animals exchange heat with their environment through

A) radiation.
B) conduction.
C) convection.
D) evaporation.
E) All of the choices for this question are correct.

Question 23

All of the following are mechanisms of thermoregulation in ectothermic animals EXCEPT

A) countercurrent heat exchangers.
B) changing the rate of heat production by muscular activity.
C) changing the rate of heat loss by vasodilation and vasoconstriction.
D) relocating to cool areas when too hot or warm areas when too cold.
E) insulation in the form of feathers or fur.

Question 24

Which of the following is an example of acclimatization?

A) sweating while working out
B) a dog moving into the shade
C) a dog panting on a hot day
D) young penguins huddling together to stay warm
E) a duck growing thick down underfeathers in fall

Question 25

During hibernation, a bear would be expected to be in the postabsorptive state in terms of nutrient utilization.

Question 26

The term "glucose sparing" refers to the increase in fat utilization seen in most tissues and organs during periods of low glucose availability.

Question 27

Insulin stimulates glycogenolysis and gluconeogenesis by the liver.

Question 28

Insulin stimulation is required to move ALL types of glucose transport proteins to the plasma membrane of the cell.

Question 29

As body fat mass increases, leptin production decreases.

Question 30

Decreases in leptin levels decrease basal metabolic rate.

Question 31

Individuals with hypothetical "thrifty genes" are proposed to be better at storing fat than individuals without these genetic variants.

Question 32

A mouse and a lizard of identical weight would be expected to have the same total metabolic rate.