MCQ Hormonal Regulation

Question 1

One distinction between peptide and steroid hormones is that peptide hormones:
A) act through nonspecific receptors, whereas steroid hormones act through specific receptors.
B) are generally water-insoluble, whereas steroid hormones are water soluble.
C) are more stable than steroid hormones.
D) bind to cell surface receptors, whereas steroid hormones bind to nuclear receptors.
E) bind to their receptors with high affinity, whereas steroid hormones bind with low affinity

Answer 1

D) bind to cell surface receptors, whereas steroid hormones bind to nuclear receptors.

Question 2

Insulin is an example of a(n) \_\_\_\_\_\_\_\_\_\_\_\_ hormone.
A) catecholamine B) eicosanoid
C) paracrine
D) peptide
E) steroid

Answer 2

D) peptide

Question 3

The maturation of insulin from its precursor (preproinsulin) involves:
A) acetylation.
B) oxidation.
C) phosphorylation. D) proteolysis.
E) reduction.

Answer 3

D) proteolysis.

Question 4

Epinephrine is an example of a(n) \_\_\_\_\_\_\_\_\_\_\_\_ hormone.
A) catecholamine B) eicosanoid
C) paracrine
D) peptide
E) steroid

Answer 4

A) catecholamine

Question 5

An example of an eicosanoid hormone is:
A) epinephrine.
B) retinoic acid.
C) testosterone.
D) thromboxane.
E) thyroxine.

Answer 5

D) thromboxane.

Question 6

The tropic hormones (such as thyrotropin, somatotropin, and luteinizing hormone) are produced and released by the:
A) anterior pituitary.
B) hypothalamus.
C) ovaries.
D) pancreas.
E) posterior pituitary.

Answer 6

A) anterior pituitary.

Question 7

Which of the following statements about metabolism in the mammalian liver is false?
A) Most plasma lipoproteins are synthesized in the liver.
B) The enzymatic complement of liver tissue changes in response to changes in the diet.
C) The liver synthesizes most of the urea produced in the body.
D) The presence of glucose 6-phosphatase makes liver uniquely able to release glucose into the
bloodstream.
E) Under certain conditions, most of the functions of the liver can be performed by other organs.

Answer 7

E) Under certain conditions, most of the functions of the liver can be performed by other organs.

Question 8

Glucokinase:
A) actsintheconversionofliverglycogentoglucose1-phosphate.
B) converts fructose-6-phosphate to glucose-6-phosphate
C) converts glucose 6-phosphate to fructose 6-phosphate.
D) isahexokinaseisozymefoundinliverhepatocytes.
E) is found in all mammalian tissues.

Answer 8

D) isahexokinaseisozymefoundinliverhepatocytes

Question 9

In skeletal muscle:
A) amino acids are an essential fuel.
B) at rest, fatty acids are the preferred fuel.
C) large quantities of triacylglycerol are stored as fuel.
D) phosphocreatine can substitute for ATP as the direct source of energy for muscle contraction.
E) stored muscle glycogen can be converted to glucose and released to replenish blood glucose.

Answer 9

at rest, fatty acids are the preferred fuel.

Question 10

Which one of the following statements is true?
A) The brain prefers glucose as an energy source, but can use ketone bodies.
B) Muscle cannot use fatty acids as an energy source.
C) In a well-fed human, about equal amounts of energy are stored as glycogen and as
triacylglycerol.
D) Fatty acids cannot be used as an energy source in humans because humans lack the enzymes of
the glyoxylate cycle.
E) Amino acids are a preferable energy source over fatty acids.

Answer 10

A) The brain prefers glucose as an energy source, but can use ketone bodies.

Question 11

When blood glucose is abnormally high, the pancreas releases:
A) epinephrine. B) glucagon. C) glucose.
D) insulin.
E) trypsin.

Answer 11

D) insulin.

Question 12

When blood glucose is abnormally low, the pancreas releases:
A) epinephrine. B) glucagon. C) glucose.
D) insulin.
E) trypsin.

Answer 12

B) glucagon.

Question 13

An elevated insulin level in the blood:
A) inhibits glucose uptake by the liver.
B) inhibits glycogen synthesis in the liver and muscle.
C) results from a below-normal blood glucose level.
D) stimulates glycogen breakdown in liver.
E) stimulates synthesis of fatty acids and triacylglycerols in the liver.

Answer 13

E) stimulates synthesis of fatty acids and triacylglycerols in the liver.

Question 14

The largest energy store in a well-nourished human is:
A) ATP in all tissues.
B) blood glucose.
C) liver glycogen.
D) muscle glycogen.
E) triacylglycerols in adipose tissue.

Answer 14

E) triacylglycerols in adipose tissue.

Question 15

Elevated epinephrine levels do not normally stimulate:
A) fatty acid mobilization in adipose tissue.
B) gluconeogenesis in liver.
C) glycogen breakdown in muscle.
D) glycogen synthesis in liver.
E) glycolysis in muscle.

Answer 15

D) glycogen synthesis in liver.

Question 16

Epinephrine triggers an increased rate of glycolysis in muscle by:
A) activationofhexokinase.
B) activation of phosphofructokinase-1.
C) conversion of glycogen phosphorylase a to glycogen phosphorylase b.
D) inhibitionoftheCoriCycle
E) the Pasteur effect.

Answer 16

B) activation of phosphofructokinase-1.

Question 17

Long-term maintenance of body weight is regulated by the hormone:
A) adiposin.
B) hypothalmin. C) leptin.
D) obesin.
E) testosterone.

Answer 17

C) leptin.

Question 18

The peptide hormone adiponectin, produced in adipose tissue, circulates in the blood and:
A) enhancesfattyacidsynthesisinlivercells.
B) increases the rate of β-oxidation of fatty acids in muscle cells.
C) inhibits glucose uptake and catabolism in muscle and liver cells.
D) reducesthetransportoffattyacidsintomusclecells.
E) stimulates gluconeogenesis in liver cells.

Answer 18

B) increases the rate of β-oxidation of fatty acids in muscle cells.