Transcript File - jj-sct

CAMPBELL
BIOLOGY
TENTH
EDITION
Reece • Urry • Cain • Wasserman • Minorsky • Jackson
11
Cell Communication
Clicker Questions by
Scott Meissner
© 2014 Pearson Education, Inc.
Which of the following gives a correct and broadest
description of signal transduction pathways?
a) binding of a signal molecule to a cell protein
b) catalysis mediated by an enzyme
c) sequence of changes in a series of molecules
resulting in a response
d) binding of a ligand on one side of a membrane
that results in a change on the other side
e) the cell’s detection of a chemical or mechanical
stimulus
© 2014 Pearson Education, Inc.
Which of the following gives a correct and broadest
description of signal transduction pathways?
a) binding of a signal molecule to a cell protein
b) catalysis mediated by an enzyme
c) sequence of changes in a series of molecules
resulting in a response
d) binding of a ligand on one side of a membrane
that results in a change on the other side
e) the cell’s detection of a chemical or mechanical
stimulus
© 2014 Pearson Education, Inc.
Matching:
Match each receptor type (1–3) to a distinctive feature
of it (A–E):
1) channel receptors
2) G protein-coupled receptors
3) receptor tyrosine kinases
a) phosphorylation
b) activation of a G protein
c) ion influx into the cell
d) dephosphorylation
e) ATP synthesis
© 2014 Pearson Education, Inc.
Matching:
Match each receptor type (1–3) to a distinctive feature
of it (A–E):
1) channel receptors
2) G protein-coupled receptors
3) receptor tyrosine kinases
a) phosphorylation
b) activation of a G protein
c) ion influx into the cell
d) dephosphorylation
e) ATP synthesis
© 2014 Pearson Education, Inc.
A steroid hormone is bound by an intracellular receptor.
When it does, the resulting complex is most likely to do
which of the following?
a) open channels in the membrane for other
substances to enter
b) open channels in the nuclear envelope for
cytoplasmic molecules to enter
c) mediate the transfer of phosphate groups to/from
ATP
d) act as a transcription factor in the nucleus
e) make water-soluble molecules able to diffuse across
membranes
© 2014 Pearson Education, Inc.
A steroid hormone is bound by an intracellular receptor.
When it does, the resulting complex is most likely to do
which of the following?
a) open channels in the membrane for other
substances to enter
b) open channels in the nuclear envelope for
cytoplasmic molecules to enter
c) mediate the transfer of phosphate groups to/from
ATP
d) act as a transcription factor in the nucleus
e) make water-soluble molecules able to diffuse across
membranes
© 2014 Pearson Education, Inc.
Weak ionic bonds formed between the negative
phosphate functional group and partially or fully positive
amino acids of proteins in a kinase cascade do which
of the following?
a) make functional ATP
b) distort a protein from one functional state
to another
c) activate phosphatases to remove the phosphate
group
d) alter the permeability of the cell’s membranes
e) produce an increase in the cell’s store of inorganic
phosphates
© 2014 Pearson Education, Inc.
Weak ionic bonds formed between the negative
phosphate functional group and partially or fully positive
amino acids of proteins in a kinase cascade do which
of the following?
a) make functional ATP
b) distort a protein from one functional state
to another
c) activate phosphatases to remove the phosphate
group
d) alter the permeability of the cell’s membranes
e) produce an increase in the cell’s store of inorganic
phosphates
© 2014 Pearson Education, Inc.
Which of the following is the best example of
amplification of signal detection?
a) production of many molecules by many signal
molecules
b) activation of 100 molecules by a single signal
binding event
c) activation of a specific gene by a transcription factor
d) conversion of the signal into many other types of
molecules
e) activation of a receptor by a hormone
© 2014 Pearson Education, Inc.
Which of the following is the best example of
amplification of signal detection?
a) production of many molecules by many signal
molecules
b) activation of 100 molecules by a single signal
binding event
c) activation of a specific gene by a transcription factor
d) conversion of the signal into many other types of
molecules
e) activation of a receptor by a hormone
© 2014 Pearson Education, Inc.
Which choice CORRECTLY describes what happens
during the transduction part of a signal transduction
response pathway?
a) Some fraction of the original signal is converted into
something else and passed through the cell.
b) Changes in protein activities and in other items
in the cell are induced by an activated receptor.
c) The original signal is amplified as it is passed
through the cell.
d) Energy from the signal is used to power the
changes needed in the cell for a response.
e) Some phenotypic feature of the cell is altered.
© 2014 Pearson Education, Inc.
Which choice CORRECTLY describes what happens
during the transduction part of a signal transduction
response pathway?
a) Some fraction of the original signal is converted into
something else and passed through the cell.
b) Changes in protein activities and in other items
in the cell are induced by an activated receptor.
c) The original signal is amplified as it is passed
through the cell.
d) Energy from the signal is used to power the
changes needed in the cell for a response.
e) Some phenotypic feature of the cell is altered.
© 2014 Pearson Education, Inc.
Which best describes what a plasma membrane-spanning
receptor (see figure) actually does upon reception of a
signal?
a) The receptor binds an extracellular signal molecule and
passes it into the cell.
b) Activated receptors directly produce a response to the
signal.
c) It uses the energy from the signal to
power its transduction.
d) Binding of the signal molecule alters
the receptor’s other binding sites
and activities.
e) It amplifies the signal, increasing its
influence in the cell.
© 2014 Pearson Education, Inc.
Which best describes what a plasma membrane-spanning
receptor (see figure) actually does upon reception of a
signal?
a) The receptor binds an extracellular signal molecule and
passes it into the cell.
b) Activated receptors directly produce a response to the
signal.
c) It uses the energy from the signal to
power its transduction.
d) Binding of the signal molecule alters
the receptor’s other binding sites
and activities.
e) It amplifies the signal, increasing its
influence in the cell.
© 2014 Pearson Education, Inc.
Of the following events, which might typically occur THIRD
in the course of a cell’s receiving and responding to a
signal?
a) An enzyme cascade occurs, increasing the number of
activated proteins.
b) A signal molecule is bound by a transmembrane tyrosine
kinase receptor protein.
c) The receptor protein complex phosphorylates other
proteins.
d) A reconfigured protein binds
to DNA, altering gene
expression.
e) Tyrosine kinase receptor
subunits dimerize.
© 2014 Pearson Education, Inc.
Of the following events, which might typically occur THIRD
in the course of a cell’s receiving and responding to a
signal?
a) An enzyme cascade occurs, increasing the number of
activated proteins.
b) A signal molecule is bound by a transmembrane tyrosine
kinase receptor protein.
c) The receptor protein complex phosphorylates other
proteins.
d) A reconfigured protein binds
to DNA, altering gene
expression.
e) Tyrosine kinase receptor
subunits dimerize.
© 2014 Pearson Education, Inc.
Which of the following statements CORRECTLY describes the
use of ligand-gated ion channel receptors?
a) Ligand binding is irreversible, resulting in a permanent
change in this ion channel’s activity.
b) The binding site of this type of receptor is most often
in the middle of the membrane.
c)
Once activated, this receptor will cause G proteins to
bind with GTP.
d) Once the ligand is bound, the ion channel activity can
alter the local membrane potential and cytosolic
concentration of the ion.
e) The ligand involved is often a phosphate
group that is covalently added to the
cytosolic side of this ion channel.
© 2014 Pearson Education, Inc.
Which of the following statements CORRECTLY describes the
use of ligand-gated ion channel receptors?
a) Ligand binding is irreversible, resulting in a permanent
change in this ion channel’s activity.
b) The binding site of this type of receptor is most often
in the middle of the membrane.
c)
Once activated, this receptor will cause G proteins to
bind with GTP.
d) Once the ligand is bound, the ion channel activity can
alter the local membrane potential and cytosolic
concentration of the ion.
e) The ligand involved is often a phosphate
group that is covalently added to the
cytosolic side of this ion channel.
© 2014 Pearson Education, Inc.
Sutherland found evidence for the presence of a G proteincoupled receptor for epinephrine in muscle cells. For this
receptor to function normally, it must have at least how
many binding sites, and what must be bound?
a) one: G protein
b) two; epinephrine and G protein
c) two: epinephrine and GTP
d) one: extracellular epinephrine
e) three: epinephrine, G protein, and
ATP
© 2014 Pearson Education, Inc.
Sutherland found evidence for the presence of a G proteincoupled receptor for epinephrine in muscle cells. For this
receptor to function normally, it must have at least how
many binding sites, and what must be bound?
a) one: G protein
b) two; epinephrine and G protein
c) two: epinephrine and GTP
d) one: extracellular epinephrine
e) three: epinephrine, G protein, and
ATP
© 2014 Pearson Education, Inc.
Which is NOT an option that is sometimes used by
cells in some type of information transduction?
a) The binding abilities of several proteins are altered.
b) The original signal is amplified many times over.
c) A cellular compartment has a change in the
concentration of a specific item.
d) Proteins are covalently modified.
e) A membrane potential gradient is altered.
© 2014 Pearson Education, Inc.
Which is NOT an option that is sometimes used by
cells in some type of information transduction?
a) The binding abilities of several proteins are altered.
b) The original signal is amplified many times over.
c) A cellular compartment has a change in the
concentration of a specific item.
d) Proteins are covalently modified.
e) A membrane potential gradient is altered.
© 2014 Pearson Education, Inc.
Which of the following INCORRECTLY describes an aspect of
the use of a second messenger in a typical signal transduction
pathway?
a) The second messenger can diffuse rapidly through the
cytosol.
b) After the rise in the concentration of the second messenger,
it is often removed quickly by degradation or export from the
cytosol.
c)
The proteins that will bind the second messenger are already
present before there is a rise in its concentration.
d) Synthesis of the enzyme that creates the second
messenger occurs right after the signal is received, and not
before.
e) When the cell does not receive the signal, the second
messenger is kept at a low concentration.
© 2014 Pearson Education, Inc.
Which of the following INCORRECTLY describes an aspect of
the use of a second messenger in a typical signal transduction
pathway?
a) The second messenger can diffuse rapidly through the
cytosol.
b) After the rise in the concentration of the second messenger,
it is often removed quickly by degradation or export from the
cytosol.
c)
The proteins that will bind the second messenger are already
present before there is a rise in its concentration.
d) Synthesis of the enzyme that creates the second
messenger occurs right after the signal is received, and
not before.
e) When the cell does not receive the signal, the second
messenger is kept at a low concentration.
© 2014 Pearson Education, Inc.
Which of the following will most likely be needed to turn
OFF a phosphorylation cascade in a cell's cytosol after
it has been used?
a) the production of new proteins by the expression of
genes that have just been turned on
b) the hydrolysis of GTP by an activated G protein
c) the removal of Ca2+ out of the cytosol by
Ca2+-pumping ATPases
d) the degradation of inositol triphosphate (IP3) by an
enzyme
e) the action of specific protein phosphatases
© 2014 Pearson Education, Inc.
Which of the following will most likely be needed to turn
OFF a phosphorylation cascade in a cell's cytosol after
it has been used?
a) the production of new proteins by the expression of
genes that have just been turned on
b) the hydrolysis of GTP by an activated G protein
c) the removal of Ca2+ out of the cytosol by
Ca2+-pumping ATPases
d) the degradation of inositol triphosphate (IP3) by an
enzyme
e) the action of specific protein phosphatases
© 2014 Pearson Education, Inc.
Which of the following INCORRECTLY describes
something about the signal-transduction response
system shown in the figure on the next slide?
a) This allows one external signal molecule to induce a
large effect in the cell.
b) The kinases do their phosphorylations by taking
phosphates from ATPs.
c) Eventually, the G proteins will cleave their GTP and
become inactive.
d) To recover and remove the cyclic AMP,
phosphodiesterase is needed.
e) This system increases the expression of the gene
for the adenylyl cyclase enzyme.
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
Which of the following INCORRECTLY describes
something about the signal-transduction response
system shown in the figure on the next slide?
a) This allows one external signal molecule to induce a
large effect in the cell.
b) The kinases do their phosphorylations by taking
phosphates from ATPs.
c) Eventually, the G proteins will cleave their GTP and
become inactive.
d) To recover and remove the cyclic AMP,
phosphodiesterase is needed.
e) This system increases the expression of the gene
for the adenylyl cyclase enzyme.
© 2014 Pearson Education, Inc.
For a cell in Caenorhabditis elegans to carry out
apoptosis properly depends in part on
a) a protein that normally inhibits the process being
turned off.
b) the creation of a “death signal” by this cell.
c) properly resetting all the transductive elements from
the last use of this process.
d) the receptor moving the
“death signal” into the nucleus
of the cell.
e) turning off various nucleases
and proteases in the cell.
© 2014 Pearson Education, Inc.
For a cell in Caenorhabditis elegans to carry out
apoptosis properly depends in part on
a) a protein that normally inhibits the process
being turned off.
b) the creation of a “death signal” by this cell.
c) properly resetting all the transductive elements from
the last use of this process.
d) the receptor moving the
“death signal” into the nucleus
of the cell.
e) turning off various nucleases
and proteases in the cell.
© 2014 Pearson Education, Inc.