Cell Signalling And Transduction

Question: In terms of cell communication, what do bacterial pathogens such as cholera and anthrax have in common?
[A].

They destroy the receptors for key signaling molecules

[B].

They prevent the production of key signaling molecules

[C].

They alter the chemical structure of key signaling molecules

[D].

They block the normal functioning of signal transduction mechanisms

Answer: Option D

Explanation:

No answer description available for this question.

Question: A signal cascade induced by adrenaline or thyroxine
[A].

must begin with receipt of the signal molecule by a surface receptor

[B].

involves the activation of a G protein

[C].

results in the activation of a sequence of enzymes needed for the cell effect

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: Why is it that inhaling nitric oxide reduces blood pressure only in the lung tissue and not elsewhere in the body*?
[A].

Because other body tissues use a different signaling molecule

[B].

Because nitric oxide cannot cross cell membranes and enter the blood

[C].

Because nitric oxide breaks down quickly and thus cannot travel far

[D].

None of the above

Answer: Option C

Explanation:

No answer description available for this question.

Question: If a disease of the blood vessels caused the endothelial cells of the vessel to die, what effect would that have on the cellular activities associated with vasodilation?
[A].

Nitric oxide would no longer be produced

[B].

Smooth muscle cells could not be made to relax

[C].

It would be more difficult to increase blood flow and reduce blood pressure

[D].

All of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: A cell is known to respond to a particular signaling molecule. Which of the following must be true of this cell?
[A].

It is in the heart muscle

[B].

It is also the site of production for the signaling molecule

[C].

It contains the receptor for the signaling molecule

[D].

It is incapable of signal transduction

Answer: Option C

Explanation:

No answer description available for this question.

Question: Which of the following processes involve the combining of a message from one signaling molecule with that of another to either enhance or inhibit a cellular effect?
[A].

Signal transduction

[B].

Signal reception

[C].

Signal integration

[D].

Signal amplification

Answer: Option C

Explanation:

No answer description available for this question.

Question: In the signal transduction mechanism known as protein phosphorylation
[A].

the signaling molecule binds to a surface receptor

[B].

receptor kinases play a key role in triggering the signal cascade

[C].

phosphorylated proteins act with enzymes to trigger the signal cascade

[D].

All of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: Which of the following statements about G proteins is false?
[A].

They are involved in signal cascades

[B].

They bind to and are regulated by guanine nucleotides

[C].

They become activated when bound to GDP

[D].

They must be active before the cell can make needed cAMP

Answer: Option C

Explanation:

No answer description available for this question.

Question: Nitroglycerin has long been administered to human patients suffering from chronic chest pain (angina). This medication works because it
[A].

mimics the action of signal receptors

[B].

is broken down into hormones that affect the heart

[C].

interferes with chemical cascades that trigger contraction of heart muscle

[D].

breaks down into nitric oxide, which increases blood flow to the heart

Answer: Option D

Explanation:

No answer description available for this question.

Question: In vasodilation, proper nerve signals sent to blood vessels cause
[A].

the release of nitric oxide from endothelial cells

[B].

relaxation of smooth muscle cells

[C].

reduced blood pressure

[D].

All of the above

Answer: Option D

Explanation:

No answer description available for this question.