Question 1

Inflammation is characterized in part by redness and swelling. In inflammation,_______ increases blood flow to affected tissues (producing redness)  and causes fluid to leak out of the blood vessels and into the tissue (producing swelling) .

Accepted Answer

A)   pyruvic acid
B)   histamine
C)   amine
D)   growth factor
E)   clotting factorF) None of the above
G) A) and E) B

Question 2

If calcium channels open in the plasma membrane, calcium ions enter the cell.

Accepted Answer

A) True 
 B)False

Question 3

Opening channels for which of the following ions can trigger exocytosis?

Accepted Answer

A)   potassium
B)   calcium
C)   magnesium
D)   sodium
E)   chlorideF) B) and C)
G) A) and B)

Question 4

What enzyme catalyzes synthesis of prostaglandins from arachidonic acid?

Accepted Answer

A)   lipoxygenase
B)   phospholipase A2
C)   phospholipase C
D)   cyclooxygenase
E)   tyrosine fi -hydroxylaseF) A) and D)
G) A) and C)

Question 5

Which of the following enzymes catalyzes synthesis of cAMP?

Accepted Answer

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

Question 6

What chemical messenger diffuses to neighboring cells to exert an effect?

Accepted Answer

A)   autocrine
B)   neurotransmitter
C)   hormone
D)   paracrine
E)   neurohormoneF) C) and E)
G) A) and C) D

Question 7

Cells that secrete epinephrine must contain which enzymes?

Accepted Answer

A)   dopamine fi -hydroxylase, tyrosine fi -hydroxylase, and dopa decarboxylase only
B)   phenylethanolamine N -methyl transferase and dopa decarboxylase only
C)   tyrosine fi -hydroxylase and phenylethanolamine N -methyl transferase only
D)   dopamine fi -hydroxylase, tyrosine fi -hydroxylase, phenylethanolamine N -methyl transferase, and dopa decarboxylase
E)   dopamine fi -hydroxylase and dopa decarboxylase onlyF) None of the above
G) A) and E)

Question 8

The target cell of a neurotransmitter is the postsynaptic cell.

Accepted Answer

A) True 
 B)False

Question 9

Communication across a synapse is initiated by the release of a neurotransmitter from the region of the neuron.

Accepted Answer

A)   axon hillock
B)   axon terminal
C)   dendritic
D)   perisynaptic
E)   postsynapticF) B) and E)
G) C) and E)

Question 10

Cells that secrete dopamine must contain which enzymes?

Accepted Answer

A)   dopamine fi -hydroxylase and dopa decarboxylase only
B)   tyrosine fi -hydroxylase
C)   dopamine fi -hydroxylase only
D)   dopa decarboxylase only
E)   tyrosine fi -hydroxylase and dopa decarboxylaseF) All of the above
G) B) and D)

Question 11

Typical responses to_________ messengers require a long time to develop because they necessitate transcription of mRNA and translation of that mRNA into a functional protein.

Accepted Answer

A)   lipophilic
B)   lipophobic
C)   protein
D)   amino acid
E)   peptideF) All of the above
G) C) and D)

Question 12

In order to terminate a cAMP -mediated response, the enzyme ________can be activated to degrade cAMP.

Accepted Answer

A)   cAMP protein kinase
B)   cAMP phosphodiesterase
C)   cAMP hydrogenase
D)   cAMP decarboxylase
E)   cAMP hydrolaseF) A) and E)
G) D) and E)

Question 13

The location of the receptor depends on whether the messenger is lipophilic or lipophobic.

Accepted Answer

A) True 
 B)False

Question 14

Lipophobic chemical messengers communicate a message to the target cell by binding to receptors on that cell's membrane.

Accepted Answer

A) True 
 B)False

Question 15

Vasopressin (antidiuretic hormone) , which is released from the posterior pituitary, is an example of what type of chemical messenger?

Accepted Answer

A)   cytokine
B)   autocrine
C)   neurotransmitter
D)   neurohormone
E)   paracrineF) C) and D)
G) B) and E)

Question 16

Which of the following statements best describes the function of tyrosine kinase?

Accepted Answer

A)   It catalyzes the formation of dopamine from L -dopa.
B)   It catalyzes the phosphorylation of a protein in the extracellular fluid.
C)   It catalyzes the phosphorylation of a protein inside a cell.
D)   It catalyzes the formation of norepinephrine from dopamine.
E)   It sequesters calcium in the cytosol.F) A) and C)
G) A) and E)

Question 17

Aspirin is a nonsteroidal anti -inflammatory drug (NSAID)  that relieves pain. Which mechanism best describes how NSAIDs work?

Accepted Answer

A)   Aspirin decreases the production of thromboxane A2, a chemical involved in blot clot formation, and COX inhibits A2 and, therefore, blood clots do not form and cause pain.
B)   Prostaglandins (PG)  are eicosanoids that produce pain and inflammation. Cyclooxygenase (COX)  is an essential enzyme in the production of PG and aspirin inhibits COX and therefore relieves pain due to the reduced production of PG.
C)   Leukotrienes are eicosanoids that produce pain and inflammation. COX is used in the lipoxygenase pathway and therefore NSAIDs stop the conversion of arachidonic acid to leukotrienes thereby reducing inflammation.
D)   When aspirin dissolves in the interstitial fluid it causes a concentration gradient and fluid is pulled from the cell reducing inflammation.
E)   The COX receptors have a greater affinity for aspirin and these speed up the reactions of healing.F) All of the above
G) A) and B)

Question 18

In its active form, a G protein has a GDP bound to its alpha unit.

Accepted Answer

A) True 
 B)False

Question 19

The number of bound receptors on a target cell depends on what two things?

Accepted Answer

A)   the concentration of the messenger and the distance it has to travel
B)   the type and concentration of receptors
C)   the concentration of the messenger and signal transduction
D)   the secretory cell and target cell
E)   the concentration of the messenger and the concentration of receptors on the target cellF) None of the above
G) A) and C)

Question 20

The location of receptors on a target cell depends on the solubility of the chemical messenger. Where would the receptors for lipophilic messengers be located?

Accepted Answer

A)   on the outside of the cell
B)   on the inside of the cell
C)   at a free floating ribosome
D)   only in the nucleus of the cell
E)   It depends on if it is an alpha, beta, or delta type receptor.F) None of the above
G) A) and C) B

Exam 5: Chemical Messengers

Inflammation is characterized in part by redness and swelling. In inflammation,_______ increases blood flow to affected tissues (producing redness) and causes fluid to leak out of the blood vessels and into the tissue (producing swelling) .

Correct AnswerverifiedB

If calcium channels open in the plasma membrane, calcium ions enter the cell.

Correct AnswerverifiedShow Answer

Opening channels for which of the following ions can trigger exocytosis?

Correct AnswerverifiedShow Answer

What enzyme catalyzes synthesis of prostaglandins from arachidonic acid?

Correct AnswerverifiedShow Answer

Which of the following enzymes catalyzes synthesis of cAMP?

Correct AnswerverifiedShow Answer

What chemical messenger diffuses to neighboring cells to exert an effect?

Correct AnswerverifiedD

Cells that secrete epinephrine must contain which enzymes?

Correct AnswerverifiedShow Answer

The target cell of a neurotransmitter is the postsynaptic cell.

Correct AnswerverifiedShow Answer

Communication across a synapse is initiated by the release of a neurotransmitter from the region of the neuron.

Correct AnswerverifiedShow Answer

Cells that secrete dopamine must contain which enzymes?

Correct AnswerverifiedShow Answer

Typical responses to_________ messengers require a long time to develop because they necessitate transcription of mRNA and translation of that mRNA into a functional protein.

Correct AnswerverifiedShow Answer

In order to terminate a cAMP -mediated response, the enzyme ________can be activated to degrade cAMP.

Correct AnswerverifiedShow Answer

The location of the receptor depends on whether the messenger is lipophilic or lipophobic.

Correct AnswerverifiedShow Answer

Lipophobic chemical messengers communicate a message to the target cell by binding to receptors on that cell's membrane.

Correct AnswerverifiedShow Answer

Vasopressin (antidiuretic hormone) , which is released from the posterior pituitary, is an example of what type of chemical messenger?

Correct AnswerverifiedShow Answer

Which of the following statements best describes the function of tyrosine kinase?

Correct AnswerverifiedShow Answer

Aspirin is a nonsteroidal anti -inflammatory drug (NSAID) that relieves pain. Which mechanism best describes how NSAIDs work?

Correct AnswerverifiedShow Answer

In its active form, a G protein has a GDP bound to its alpha unit.

Correct AnswerverifiedShow Answer

The number of bound receptors on a target cell depends on what two things?

Correct AnswerverifiedShow Answer

The location of receptors on a target cell depends on the solubility of the chemical messenger. Where would the receptors for lipophilic messengers be located?

Correct AnswerverifiedB

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B