Question 1

Usually transported via the circulatory system, _______ are signals sent to distant cells.

Accepted Answer

The answer of Usually transported via the circulatory system, _______...

Question 2

Which of the following cellular responses to signal transduction would include activation of transcription?

Accepted Answer

A)  Rapid enzyme activation 
B)  Rapid enzyme inhibition 
C)  Opening of ion channels in the plasma membrane 
D)  Icreased expression of certain genes 
E)  Changes in the calcium concentration in the cytosol 
A)  Rapid enzyme activation 
B)  Rapid enzyme inhibition 
C)  Opening of ion channels in the plasma membrane 
D)  Icreased expression of certain genes 
E)  Changes in the calcium concentration in the cytosol

Question 3

When activated, some receptor proteins catalyze the transfer of a(n) _______ group from ATP to a specific protein. Such receptor proteins are known as protein _______.

Accepted Answer

The answer of When activated, some receptor proteins catalyze the...

Question 4

Which of the following molecules has a protein kinase receptor?

Accepted Answer

A)  Insulin 
B)  Estrogen 
C)  Acetylcholine 
D)  Sodium 
E)  G proteins 
A)  Insulin 
B)  Estrogen 
C)  Acetylcholine 
D)  Sodium 
E)  G proteins

Question 5

Which of the following is true?

Accepted Answer

A)  Direct transduction is more common than indirect transduction. 
B)  In indirect transduction, second messengers mediate the interaction between the receptor and the cell's response. 
C)  Amplification never occurs via second messengers. 
D)  Indirect transduction occurs at the plasma membrane. 
E)  All of the above 
A)  Direct transduction is more common than indirect transduction. 
B)  In indirect transduction, second messengers mediate the interaction between the receptor and the cell's response. 
C)  Amplification never occurs via second messengers. 
D)  Indirect transduction occurs at the plasma membrane. 
E)  All of the above

Question 6

In the E. coli signal transduction pathway, which of the following protein molecules acts as the responder?

Accepted Answer

A)  OmpR 
B)  EnvZ 
C)  SORp 
D)  Autocrine 
E)  None of the above 
A)  OmpR 
B)  EnvZ 
C)  SORp 
D)  Autocrine 
E)  None of the above

Question 7

Which of the following is false?

Accepted Answer

A)  Cells are bombarded with numerous signals, but they respond to only a few. 
B)  A cell's receptors determine whether or not the cell will respond to a signal. 
C)  Receptor proteins are very specific. 
D)  There are only a few kinds of signal receptor proteins. 
E)  None of the above 
A)  Cells are bombarded with numerous signals, but they respond to only a few. 
B)  A cell's receptors determine whether or not the cell will respond to a signal. 
C)  Receptor proteins are very specific. 
D)  There are only a few kinds of signal receptor proteins. 
E)  None of the above

Question 8

Which structure narrows the opening of the plasmodesma?

Accepted Answer

A)  A gap junction 
B)  Connexons 
C)  A desmotubule 
D)  A ligand 
E)  A protein kinase 
A)  A gap junction 
B)  Connexons 
C)  A desmotubule 
D)  A ligand 
E)  A protein kinase

Question 9

EnvZ of E. coli

Accepted Answer

A)  is present in the outer membrane of the bacterium. 
B)  is a peripheral membrane protein. 
C)  senses when the bacterium is in a region of high external solute concentration. 
D)  directly affects solute entry into the cell. 
E)  binds directly to DNA. 
A)  is present in the outer membrane of the bacterium. 
B)  is a peripheral membrane protein. 
C)  senses when the bacterium is in a region of high external solute concentration. 
D)  directly affects solute entry into the cell. 
E)  binds directly to DNA.

Question 10

Paracrine signals

Accepted Answer

A)  act on the cells that made them. 
B)  move through the blood and act on cells far from their source. 
C)  act on cells that are near to those that secrete them. 
D)  do not act through receptors. 
E)  require large concentrations of the signaling molecule to function. 
A)  act on the cells that made them. 
B)  move through the blood and act on cells far from their source. 
C)  act on cells that are near to those that secrete them. 
D)  do not act through receptors. 
E)  require large concentrations of the signaling molecule to function.

Question 11

Cells receive which of the following signals?

Accepted Answer

A)  Light 
B)  Sound 
C)  Odorants 
D)  Hormones 
E)  All of the above 
A)  Light 
B)  Sound 
C)  Odorants 
D)  Hormones 
E)  All of the above

Question 12

Which of the following is not part of the IP3 / DAG pathway?

Accepted Answer

A)  The binding of a hormone to a receptor 
B)  The production of IP3 by a G protein 
C)  Activation of phospholipase C 
D)  The opening of Ca2+ channels 
E)  All of the above are part of the pathway. 
A)  The binding of a hormone to a receptor 
B)  The production of IP3 by a G protein 
C)  Activation of phospholipase C 
D)  The opening of Ca2+ channels 
E)  All of the above are part of the pathway.

Question 13

Signal molecules can be divided into two general classes according to their receptors. What are these two kinds of receptors?

Accepted Answer

A)  Plasma membrane and ion channel 
B)  Plasma membrane and protein kinase 
C)  Ion channel and protein kinase 
D)  G protein-linked and protein kinase 
E)  None of the above 
A)  Plasma membrane and ion channel 
B)  Plasma membrane and protein kinase 
C)  Ion channel and protein kinase 
D)  G protein-linked and protein kinase 
E)  None of the above

Question 14

Which of the following is not a common type of receptor?

Accepted Answer

A)  Ion channel 
B)  Protein kinase 
C)  G protein-linked receptor 
D)  Cytoplasmic receptor 
E)  Adenylyl cyclase 
A)  Ion channel 
B)  Protein kinase 
C)  G protein-linked receptor 
D)  Cytoplasmic receptor 
E)  Adenylyl cyclase

Question 15

The hydrolysis of PIP2 results in

Accepted Answer

A)  inositol triphosphate and diacylglycerol. 
B)  inositol triphosphate and cyclic AMP. 
C)  two second messengers. 
D)  Both a and c 
E)  Both b and c 
A)  inositol triphosphate and diacylglycerol. 
B)  inositol triphosphate and cyclic AMP. 
C)  two second messengers. 
D)  Both a and c 
E)  Both b and c

Question 16

Which of the following signals results in the direct activation of an enzyme?

Accepted Answer

A)  Acetylcholine binding to its receptor 
B)  Insulin binding to its receptor 
C)  Cortisol binding to its receptor 
D)  Fertilization of an egg by a sperm cell 
E)  All of the above 
A)  Acetylcholine binding to its receptor 
B)  Insulin binding to its receptor 
C)  Cortisol binding to its receptor 
D)  Fertilization of an egg by a sperm cell 
E)  All of the above

Question 17

How does a protein kinase cascade amplify an intercellular signal?

Accepted Answer

A)  Protein kinase opens cell junctions, amplifying the intercellular signal. 
B)  The activated G protein binds and activates a second protein, amplifying the signal. 
C)  Nitric oxide opens cell channels, which allows protein kinase molecules to move quickly from cell to cell. 
D)  Second messengers create shortcuts that create multiple cascades. 
E)  One activated receptor kinase molecule can trigger the activation of thousands of proteins. 
A)  Protein kinase opens cell junctions, amplifying the intercellular signal. 
B)  The activated G protein binds and activates a second protein, amplifying the signal. 
C)  Nitric oxide opens cell channels, which allows protein kinase molecules to move quickly from cell to cell. 
D)  Second messengers create shortcuts that create multiple cascades. 
E)  One activated receptor kinase molecule can trigger the activation of thousands of proteins.

Question 18

An external stimulus causes a specific intracellular response. Which is the most likely order in which signal transducers would work?

Accepted Answer

A)  G protein; cAMP; protein kinase 
B)  protein kinase; cAMP; G protein 
C)  cAMP; protein kinase; G protein 
D)  protein kinase; G protein; cAMP 
E)  cAMP; G protein; protein kinase 
A)  G protein; cAMP; protein kinase 
B)  protein kinase; cAMP; G protein 
C)  cAMP; protein kinase; G protein 
D)  protein kinase; G protein; cAMP 
E)  cAMP; G protein; protein kinase

Question 19

A nonpolar molecule such as a steroid hormone usually binds to a

Accepted Answer

A)  cytoplasmic receptor. 
B)  protein kinase. 
C)  ion channel. 
D)  phospholipid. 
E)  second messenger. 
A)  cytoplasmic receptor. 
B)  protein kinase. 
C)  ion channel. 
D)  phospholipid. 
E)  second messenger.

Question 20

Describe how protein kinases and G protein-linked receptors may interact in a signal transduction cascade.

Accepted Answer

G protein-linked rec

Exam 7: Cell Signaling and Communication

Usually transported via the circulatory system, _______ are signals sent to distant cells.

Which of the following cellular responses to signal transduction would include activation of transcription?

When activated, some receptor proteins catalyze the transfer of a(n) _______ group from ATP to a specific protein. Such receptor proteins are known as protein _______.

Which of the following molecules has a protein kinase receptor?

Which of the following is true?

In the E. coli signal transduction pathway, which of the following protein molecules acts as the responder?

Which of the following is false?

Which structure narrows the opening of the plasmodesma?

EnvZ of E. coli

Paracrine signals

Cells receive which of the following signals?

Which of the following is not part of the IP3 / DAG pathway?

Signal molecules can be divided into two general classes according to their receptors. What are these two kinds of receptors?

Which of the following is not a common type of receptor?

The hydrolysis of PIP2 results in

Which of the following signals results in the direct activation of an enzyme?

How does a protein kinase cascade amplify an intercellular signal?

An external stimulus causes a specific intracellular response. Which is the most likely order in which signal transducers would work?

A nonpolar molecule such as a steroid hormone usually binds to a

Describe how protein kinases and G protein-linked receptors may interact in a signal transduction cascade.

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Filters

When activated, some receptor proteins catalyze the transfer of a(n) _ group from ATP to a specific protein. Such receptor proteins are known as protein _.

Which of the following is not part of the IP₃ / DAG pathway?