Question 1

Your research project involves the characterization of a particular signal transduction pathway.Specifically,you have been studying a receptor tyrosine kinase and protein X,which initiates downstream events.You are certain that protein X is part of the signal transduction pathway,but have been unable to identify a direct protein-protein interaction between the receptor tyrosine kinase and the protein X.What should you do next in your attempt to identify a link between the receptor tyrosine kinase and protein X?

Accepted Answer

A)  Try to identify a coactivator protein.
B)  Try to identify proteins that act downstream of protein X.
C)  Try to identify an adapter protein that can interact with both the receptor and protein X.
D)  Confirm the interaction between the receptor tyrosine kinase and its ligand.E) A) and B)
F) A) and C)

Question 2

Vasopressin is a hormone that is primarily released when the body is low on water.Release of vasopressin causes the kidneys to conserve water by concentrating urine and decreasing urine output.However,vasopressin also has additional functions in other tissues such as the brain and blood vessels,which are not directly involved in urine production.How could it be possible for vasopressin to trigger different responses in different tissues?

Accepted Answer

A)  Vasopressin can bind to,and act on,different receptor subtypes,leading to different cellular responses in different tissues.
B)  Vasopressin can be released at different times to result in different effects.
C)  Vasopressin binds to the same exact receptor in different tissues,but causes a different conformational change to the receptor in each tissue.
D)  The kidneys have a receptor for vasopressin,but cells in the brain and blood vessels do not have a receptor for vasopressin.E) B) and D)
F) All of the above

Question 3

What type of receptor is not an enzyme,but is directly associated with an enzyme that can hydrolyze GTP?

Accepted Answer

A)  Channel-linked receptor
B)  Enzymatic receptor
C)  G protein-coupled receptor
D)  Steroid hormone receptorE) A) and C)
F) A) and B)

Question 4

What property defines most ligands for intracellular receptors?

Accepted Answer

A)  They are lipid-soluble
B)  They are hydrophilic
C)  They are molecules that can perform significant hydrogen bonding interactions with water
D)  They are large moleculesE) None of the above
F) B) and D)

Question 5

The cell surface receptors that can act only indirectly on plasma membrane-bound enzymes or ion channels are called:

Accepted Answer

A)  G protein-coupled receptors.
B)  gated ion channels.
C)  enzymatic receptors.
D)  second messenger receptors.E) A) and B)
F) B) and C)

Exam 9: Cell Communication

Correct Answer
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What property defines most ligands for intracellular receptors?

Correct Answer
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Correct Answer
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The cell surface receptors that can act only indirectly on plasma membrane-bound enzymes or ion channels are called:

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What type of receptor is not an enzyme,but is directly associated with an enzyme that can hydrolyze GTP?

Correct Answer
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Exam 9: Cell Communication

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What property defines most ligands for intracellular receptors?

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Correct AnswerverifiedShow Answer

The cell surface receptors that can act only indirectly on plasma membrane-bound enzymes or ion channels are called:

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What type of receptor is not an enzyme,but is directly associated with an enzyme that can hydrolyze GTP?

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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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Correct Answer
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