Question 1

All the messengers in what class are derived from cholesterol?

Accepted Answer

A)   eicosanoids
B)   peptides/proteins
C)   steroids
D)   amines
E)   amino acidsF) A) and B)
G) B) and D)

Question 2

What two systems primarily control homeostasis due to their ability to communicate over long distances?

Accepted Answer

A)   nervous and cardiovascular
B)   nervous and endocrine
C)   endocrine and cardiovascular
D)   endocrine and respiratory
E)   cardiovascular and respiratoryF) B) and E)
G) A) and B)

Question 3

Heroin overdose is usually treated with an opioid_______ such as naloxone (Narcan)  or naltrexone, an opioid, which prevents heroin from binding to mu receptors and reverses the effects of heroin on the body.

Accepted Answer

A)   ligand
B)   antagonist
C)   agonist
D)   antihistamine
E)   second messengerF) C) and D)
G) A) and B)

Question 4

Differences in the rate of activity between fast and slow ligand -gated channels are caused by

Accepted Answer

A)   G protein activity gating the fast channel.
B)   G protein activity gating the slow channel.
C)   ligand selectivity.
D)   ligand affinity.
E)   ligands gating both channels to the closed state.F) A) and B)
G) B) and E)

Question 5

A target cell will respond to a chemical messenger once that molecule has bound to a

Accepted Answer

A)   G protein.
B)   receptor.
C)   protein kinase.
D)   complex in the nucleus.
E)   calcium channel.F) A) and B)
G) B) and C)

Question 6

Which of the following chemical messengers are lipophobic?

Accepted Answer

A)   steroids
B)   peptides/proteins
C)   thyroid hormones
D)   peptides/proteins and steroids
E)   amino acidsF) C) and E)
G) D) and E)

Question 7

Which of the following enzymes catalyzes dephosphorylation of a protein?

Accepted Answer

A)   cyclooxygenase
B)   phenylethanolamine N -methyl transferase
C)   dopamine fi -hydroxylase
D)   phosphoprotein phosphatase
E)   phospholipase CF) A) and E)
G) B) and E)

Question 8

Steroid hormones are derived from the hormone testosterone.

Accepted Answer

A) True 
 B)False

Question 9

All catecholamine -secreting cells synthesize dopamine.

Accepted Answer

A) True 
 B)False

Question 10

The a1 adrenergic receptor has the greatest affinity for what messenger?

Accepted Answer

A)   serotonin
B)   epinephrine
C)   dopamine
D)   norepinephrine
E)   epinephrine and norepinephrine equallyF) A) and D)
G) A) and C)

Question 11

Describe the function of both slow and fast channel -linked receptors. Include the role of calcium as a second messenger.

Accepted Answer

Channel -linked receptors function in th...

Question 12

Which of the following proteins is directly activated by a G protein?

Accepted Answer

A)   phospholipase A2
B)   protein kinase G
C)   tyrosine kinase
D)   adenylate cyclase
E)   calmodulinF) C) and D)
G) D) and E)

Question 13

What organelle packages peptide/protein messengers into secretory vesicles?

Accepted Answer

A)   nucleus
B)   smooth endoplasmic reticulum
C)   rough endoplasmic reticulum
D)   Golgi apparatus
E)   lysosomesF) C) and D)
G) None of the above

Question 14

The site of communication between two neurons is called a synapse.

Accepted Answer

A) True 
 B)False

Question 15

Which type of chemical messenger is released into the bloodstream by an endocrine gland where it can affect target cells throughout the body?

Accepted Answer

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

Question 16

As a general rule, the magnitude of a target cell's response to a chemical messenger depends on which three factors?

Accepted Answer

A)   (1)  the concentration of the messenger, (2)  the number of receptors, and (3)  the affinity of the receptor for the messenger
B)   (1)  the solubility of the chemical messenger, (2)  the location of the receptor, and (3)  the affinity of the receptor to the messenger
C)   (1)  the concentration of the messenger, (2)  the percent saturation of the receptor, and (3)  the specificity of the receptor for the chemical messenger
D)   (1)  the half life of the messenger, (2)  the number of receptors, and (3)  the percent saturation of those receptors
E)   (1)  the solubility of the chemical messenger, (2)  the location of the receptor, and (3)  the class of the receptorF) C) and D)
G) D) and E)

Question 17

Chronic exposure to a ligand (messenger)  ______the receptor population for that chemical messenger on the target cell.

Accepted Answer

A)   changes the conformation of
B)   decreases the specificity of
C)   upregulates
D)   down regulates
E)   decreases the affinity ofF) B) and D)
G) B) and C)

Question 18

Doctors often prescribe baby aspirin (82 mg)  to guard against the formation of blood clots instead of a higher dose of 350 mg found in a regular aspirin. Which statement best describes the distinction in dosages?

Accepted Answer

A)   Aspirin causes several side effects, some good and some bad. Aspirin decreases thromboxane A2 which causes blood clots; however, at higher dosages, it also decreases the production of PGI2 (prostacyclin)  that inhibits production of blood clots. Thus, higher dosages of aspirin would actually promote the formation of blood clots.
B)   Aspirin is an allosteric modulator that activates COX -2 in the body and it is COX -2 that primarily inhibits blood clot formation.
C)   Aspirin inhibits the production of PGE2 in the stomach, which protects the stomach lining from stomach acid causing ulcers. Lower dosages do not inhibit PGE2 and do not harm the stomach.
D)   Low dosages of aspirin inhibit a critical enzyme in the production of prostaglandins called cyclooxygenase (COX) . There are two forms of COX: 1 and 2. Low dosages enhance the production of COX -2 which reduces blood clots. COX -1 receptors only reduce pain.
E)   Both dosages actually do the same thing to prevent blood clots but 82 mg of aspirin is much cheaper than 350 mg.F) A) and B)
G) C) and D)

Question 19

Cholera is the leading cause of death in children in developing countries, characterized by massive diarrhea. The effects stem from an extracellular toxin that the bacterium Vibrio cholerae releases into the gut. The toxin acts on a ________ that overstimulates _______Which causes a cascade of Events that leads to electrolytes leaving the cell and causing water to follow them into the lumen of the intestine, resulting in severe diarrhea.

Accepted Answer

A)   G proteins : adenylate cyclase
B)   protein kinases : calmodulin
C)   cAMP : G proteins
D)   protein -P : GTP
E)   calcium : musclesF) B) and E)
G) C) and D)

Question 20

Which of the following enzymes catalyzes phosphorylation of a protein?

Accepted Answer

A)   tyrosine kinase
B)   phospholipase A2
C)   tyrosine fi -hydroxylase
D)   adenylate cyclase
E)   phosphodiesteraseF) B) and C)
G) D) and E)

Exam 5: Chemical Messengers

Doctors often prescribe baby aspirin (82 mg) to guard against the formation of blood clots instead of a higher dose of 350 mg found in a regular aspirin. Which statement best describes the distinction in dosages?

Correct Answer
verified

All the messengers in what class are derived from cholesterol?

Correct Answer
verified

Chronic exposure to a ligand (messenger) ______the receptor population for that chemical messenger on the target cell.

Correct Answer
verified

Describe the function of both slow and fast channel -linked receptors. Include the role of calcium as a second messenger.

Correct Answer
verified
Channel -linked receptors function in th...
View Answer

What organelle packages peptide/protein messengers into secretory vesicles?

Correct Answer
verified

As a general rule, the magnitude of a target cell's response to a chemical messenger depends on which three factors?

Correct Answer
verified

Which of the following proteins is directly activated by a G protein?

Correct Answer
verified

Correct Answer
verified

What two systems primarily control homeostasis due to their ability to communicate over long distances?

Correct Answer
verified

The a₁adrenergic receptor has the greatest affinity for what messenger?

Correct Answer
verified

A target cell will respond to a chemical messenger once that molecule has bound to a

Correct Answer
verified

The site of communication between two neurons is called a synapse.

Correct Answer
verified

Heroin overdose is usually treated with an opioid_______ such as naloxone (Narcan) or naltrexone, an opioid, which prevents heroin from binding to mu receptors and reverses the effects of heroin on the body.

Correct Answer
verified

Which of the following chemical messengers are lipophobic?

Correct Answer
verified

All catecholamine -secreting cells synthesize dopamine.

Correct Answer
verified

Steroid hormones are derived from the hormone testosterone.

Correct Answer
verified

Differences in the rate of activity between fast and slow ligand -gated channels are caused by

Correct Answer
verified

Which type of chemical messenger is released into the bloodstream by an endocrine gland where it can affect target cells throughout the body?

Correct Answer
verified

Which of the following enzymes catalyzes dephosphorylation of a protein?

Correct Answer
verified

Which of the following enzymes catalyzes phosphorylation of a protein?

Correct Answer
verified

Exam 5: Chemical Messengers

Doctors often prescribe baby aspirin (82 mg) to guard against the formation of blood clots instead of a higher dose of 350 mg found in a regular aspirin. Which statement best describes the distinction in dosages?

Correct AnswerverifiedShow Answer

All the messengers in what class are derived from cholesterol?

Correct AnswerverifiedShow Answer

Chronic exposure to a ligand (messenger) ______the receptor population for that chemical messenger on the target cell.

Correct AnswerverifiedShow Answer

Describe the function of both slow and fast channel -linked receptors. Include the role of calcium as a second messenger.

Correct AnswerverifiedChannel -linked receptors function in th...View AnswerShow Answer

What organelle packages peptide/protein messengers into secretory vesicles?

Correct AnswerverifiedShow Answer

As a general rule, the magnitude of a target cell's response to a chemical messenger depends on which three factors?

Correct AnswerverifiedShow Answer

Which of the following proteins is directly activated by a G protein?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

What two systems primarily control homeostasis due to their ability to communicate over long distances?

Correct AnswerverifiedShow Answer

The a1 adrenergic receptor has the greatest affinity for what messenger?

Correct AnswerverifiedShow Answer

A target cell will respond to a chemical messenger once that molecule has bound to a

Correct AnswerverifiedShow Answer

The site of communication between two neurons is called a synapse.

Correct AnswerverifiedShow Answer

Heroin overdose is usually treated with an opioid_______ such as naloxone (Narcan) or naltrexone, an opioid, which prevents heroin from binding to mu receptors and reverses the effects of heroin on the body.

Correct AnswerverifiedShow Answer

Which of the following chemical messengers are lipophobic?

Correct AnswerverifiedShow Answer

All catecholamine -secreting cells synthesize dopamine.

Correct AnswerverifiedShow Answer

Steroid hormones are derived from the hormone testosterone.

Correct AnswerverifiedShow Answer

Differences in the rate of activity between fast and slow ligand -gated channels are caused by

Correct AnswerverifiedShow Answer

Which type of chemical messenger is released into the bloodstream by an endocrine gland where it can affect target cells throughout the body?

Correct AnswerverifiedShow Answer

Which of the following enzymes catalyzes dephosphorylation of a protein?

Correct AnswerverifiedShow Answer

Which of the following enzymes catalyzes phosphorylation of a protein?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
verified
Channel -linked receptors function in th...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The a₁adrenergic receptor has the greatest affinity for what messenger?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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