Question 1

Most receptors are relatively non -specific for the ligand that will bind to them.

Accepted Answer

A) True 
 B)False

Question 2

Which type of chemical messenger is released from the axon terminal of a neuron and directly communicates with other cells?

Accepted Answer

A)   hormone
B)   paracrine
C)   cytokine
D)   neurotransmitter
E)   autocrineF) A) and B)
G) None of the above

Question 3

Most amines are________ , meaning they dissolve in water and therefore cannot cross the cell membrane. The ________hormones are an exception because they are ________and can easily cross the cell membrane.

Accepted Answer

A)   lipophilic : thyroid : lipophobic
B)   lipophilic : protein : lipophobic
C)   hydrophobic : steroid : hydrophilic
D)   lipophobic : thyroid : lipophilic
E)   amino acids : steroid : lipophilicF) A) and E)
G) B) and E)

Question 4

Which of the following are second messengers?

Accepted Answer

A)   cAMP only
B)   calcium only
C)   inositol triphosphate only
D)   both cAMP and inositol triphosphate
E)   cAMP, calcium, and inositol triphosphateF) D) and E)
G) None of the above

Question 5

The strength with which a ligand (chemical messenger)  will bind with a receptor is referred to as its

Accepted Answer

A)   affinity.
B)   enzyme -substrate complex.
C)   prohormone.
D)   binding strength.
E)   prepropeptide.F) A) and B)
G) C) and D)

Question 6

Which of the following enzymes catalyzes synthesis of epinephrine from norepinephrine?

Accepted Answer

A)   dopa decarboxylase
B)   dopamine fi -hydroxylase
C)   phospholipase C
D)   phenylethanolamine N -methyl transferase
E)   phosphoprotein phosphataseF) A) and E)
G) A) and C)

Question 7

When associated with G protein, guanylate cyclase will activate what enzyme?

Accepted Answer

A)   phosphodiesterase
B)   protein kinase G
C)   protein kinase A
D)   protein kinase C
E)   phospholipase CF) C) and E)
G) A) and C)

Question 8

The chemical messenger of the nervous system is _______and chemical messenger of the endocrine system is _______.

Accepted Answer

A)   neurotransmitter : hormone
B)   neurohormone : adrenocorticoid
C)   neurotransmitter : neurohormone
D)   hormone : neurotransmitter
E)   autocrines : paracrinesF) B) and E)
G) A) and E)

Question 9

Eicosanoids are released immediately upon synthesis.

Accepted Answer

A) True 
 B)False

Question 10

Peptide hormones are made______, stored and released via_______.

Accepted Answer

A)   on demand : active transport
B)   on demand : simple diffusion
C)   in advance : exocytosis , stored and released via .
D)   in advance : receptor -mediated endocytosis
E)   in advance : pinocytosisF) D) and E)
G) A) and C)

Question 11

The affinity of a receptor for its ligand is a measure of the

Accepted Answer

A)   strength of binding between ligand and receptor.
B)   percent of receptors on a specific target cell with bound ligand.
C)   number of binding sites available for the ligand.
D)   response produced in the target cell when the ligand binds to the receptor.
E)   ability of the ligand to permeate the plasma membrane and reach its receptor.F) A) and B)
G) A) and C)

Question 12

What molecules are hydrophobic and can easily cross the plasma membrane?

Accepted Answer

A)   amino acids
B)   hydrophilic
C)   lipophobic
D)   lipophilic
E)   hyperdermicF) B) and E)
G) None of the above

Question 13

What terminates the cAMP second messenger system?

Accepted Answer

A)   the release of the first messenger from the receptor
B)   a G protein
C)   the axon terminal
D)   degradation of cAMP by the liver
E)   the degradation of cAMP by the enzyme cAMP phosphodiesteraseF) A) and E)
G) B) and D)

Question 14

Hormones that are dissolved in blood typically exhibit a half -life on the order of______ , whereas Hormones that are bound to carrier  proteins can remain undegraded for______ .

Accepted Answer

A)   minutes : hours
B)   minutes : seconds
C)   hours : minutes
D)   seconds : hours
E)   seconds : minutesF) C) and D)
G) A) and E)

Question 15

Which of the following statements best describes the release of a lipophilic messenger?

Accepted Answer

A)   Lipophilic messengers are stored in vesicles and released by exocytosis in response to a stimulus.
B)   Lipophilic messengers are stored in vesicles and released by simple diffusion in response to a stimulus.
C)   Lipophilic messengers are stored in vesicles and released by exocytosis immediately after synthesis.
D)   Lipophilic messengers are stored free in the cytosol and released by simple diffusion in response to a stimulus.
E)   Lipophilic messengers are released immediately upon synthesis by simple diffusion.F) A) and D)
G) None of the above

Question 16

Which of the following chemical messengers is lipophilic and is therefore able to cross the cell membrane?

Accepted Answer

A)   peptides
B)   amino acids
C)   amines (excluding thyroid hormone) 
D)   eicosanoids
E)   proteinsF) D) and E)
G) A) and B)

Question 17

The nervous system communicates via the_______ and the endocrine system communicates via the_______ .

Accepted Answer

A)   neuron : endocrine gland
B)   glial cell : hormone
C)   muscle cells : specific target cells of hormones
D)   synapse : bloodstream
E)   electrical signals : chemical signals or paracrine cellsF) B) and C)
G) A) and B)

Question 18

A single cell can have receptors for different messengers.

Accepted Answer

A) True 
 B)False

Question 19

Endocrine glands secrete neurohormones.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following enzymes catalyzes synthesis of prostaglandins and thromboxanes?

Accepted Answer

A)   cyclooxygenase
B)   phospholipase C
C)   dopamine fi -hydroxylase
D)   phenylethanolamine N -methyl transferase
E)   phosphoprotein phosphataseF) All of the above
G) C) and E)

Exam 5: Chemical Messengers

Hormones that are dissolved in blood typically exhibit a half -life on the order of______ , whereas Hormones that are bound to carrier proteins can remain undegraded for______ .

Correct AnswerverifiedShow Answer

A single cell can have receptors for different messengers.

Correct AnswerverifiedShow Answer

The nervous system communicates via the_______ and the endocrine system communicates via the_______ .

Correct AnswerverifiedShow Answer

What molecules are hydrophobic and can easily cross the plasma membrane?

Correct AnswerverifiedShow Answer

When associated with G protein, guanylate cyclase will activate what enzyme?

Correct AnswerverifiedShow Answer

The affinity of a receptor for its ligand is a measure of the

Correct AnswerverifiedShow Answer

Peptide hormones are made______, stored and released via_______.

Correct AnswerverifiedShow Answer

Which type of chemical messenger is released from the axon terminal of a neuron and directly communicates with other cells?

Correct AnswerverifiedShow Answer

Which of the following statements best describes the release of a lipophilic messenger?

Correct AnswerverifiedShow Answer

Which of the following are second messengers?

Correct AnswerverifiedShow Answer

Which of the following chemical messengers is lipophilic and is therefore able to cross the cell membrane?

Correct AnswerverifiedShow Answer

Endocrine glands secrete neurohormones.

Correct AnswerverifiedShow Answer

Most receptors are relatively non -specific for the ligand that will bind to them.

Correct AnswerverifiedShow Answer

Eicosanoids are released immediately upon synthesis.

Correct AnswerverifiedShow Answer

The strength with which a ligand (chemical messenger) will bind with a receptor is referred to as its

Correct AnswerverifiedShow Answer

The chemical messenger of the nervous system is _______and chemical messenger of the endocrine system is _______.

Correct AnswerverifiedShow Answer

Which of the following enzymes catalyzes synthesis of epinephrine from norepinephrine?

Correct AnswerverifiedShow Answer

What terminates the cAMP second messenger system?

Correct AnswerverifiedShow Answer

Most amines are________ , meaning they dissolve in water and therefore cannot cross the cell membrane. The ________hormones are an exception because they are ________and can easily cross the cell membrane.

Correct AnswerverifiedShow Answer

Which of the following enzymes catalyzes synthesis of prostaglandins and thromboxanes?

Correct AnswerverifiedShow Answer

Hormones that are dissolved in blood typically exhibit a half -life on the order of , whereas Hormones that are bound to carrier proteins can remain undegraded for .

Correct Answer
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The nervous system communicates via the_ and the endocrine system communicates via the_ .

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Peptide hormones are made, stored and released via_.

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The chemical messenger of the nervous system is _and chemical messenger of the endocrine system is _.

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Most amines are , meaning they dissolve in water and therefore cannot cross the cell membrane. The hormones are an exception because they are and can easily cross the cell membrane.

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