Cell Bio Exam ACTUAL QUESTIONS
AND CORRECT ANSWERS
assignment 5 - CORRECT ANSWERS✅✅
Many of the extracellular signal molecules that regulate inflammation are released locally at
the site of infection. What form of cell-cell signaling is being used?
paracrine
endocrine
neuronal
contact-dependent - CORRECT ANSWERS✅✅paracrine
What does a target cell require to respond to an extracellular signal molecule?
- effector molecules that alter cell behavior in response to the signal molecule
- appropriate intracellular signaling pathways
-access to the signal molecule
-the appropriate machinery to produce and secrete the signal molecule
- a receptor that recognizes the signal molecule - CORRECT ANSWERS✅✅all except... the
appropriate machinery
Which statement about cell signaling is correct?
- each receptor triggers one particular type of cell behavior, for example, activating gene
expression
- all extracellular signal molecules act by binding to receptors on the cell surface
- all cell types are able to respond to the same set of signal molecules
- each receptor is generally activated by only one type of signal molecule
- each type of extracellular signal molecule induces the same response in all target cells -
CORRECT ANSWERS✅✅each receptor is generally activated by only one type of signal
molecule
What makes it possible for a combination of signal molecules to evoke a response that differs
from the sum of the effects that each signal could trigger on its own?
,- the tendency of different cells to display different receptors
- the ability of different intracellular relay systems to interact
- the ability of different signal molecules to bind to the same receptor
- the ability of the same signal molecule to bind to different receptors
- the ability of different receptors to activate different intracellular relay systems - CORRECT
ANSWERS✅✅the ability of different intracellular relay systems to interact
Under what condition will a target cell always respond quickly to an extracellular signal?
- the response relies on second messengers
- the signal molecules binds to an intracellular receptor
- the signal molecule is small
- the response does not require changes in gene expression
- the signal molecule is present in high concentrations - CORRECT ANSWERS✅✅the
response does not require changes in gene expression
Which of the following signaling pathways would be likely to trigger the most rapid cell
response?
- Acetylcholine binds to anion-channel-coupled receptor that allows Na+ to flow down its
electrochemical gradient, triggering contraction of a skeletal muscle cell.
- Adrenaline binds to a GPCR to activate a cyclic AMP signaling pathway that triggers the
synthesis of hormones in endocrine cells.
- Platelet-derived growth factor binds to a receptor tyrosine kinase to activate a signaling
pathway that stimulates cell proliferation at the site of a wound.
- Nerve growth factor binds to a receptor tyrosine kinase to activate a signaling pathway that
enhances the transcription of Bcl2, a protein that suppresses cell death.
- Adrenaline binds to a GPCR to activate a cyclic AMP signaling pathway that triggers
glycogen breakdown. - CORRECT ANSWERS✅✅Acetylcholine binds to anion-channel-
coupled receptor that allows Na+ to flow down its electrochemical gradient, triggering
contraction of a skeletal muscle cell
Which of the following statements is true?
- G-protein-coupled receptors are GTP-binding proteins
- all enzyme-coupled receptors have an intrinsic catalytic domain on the cytosolic side of the
plasma membrane
, - many ion-channel-coupled receptors have an intrinsic catalytic domain on the cytosolic side
of the plasma membrane
- ion-channel-coupled receptors can rapidly alter the membrane potential in response to signal
binding
- each extracellular signal molecule interacts with a single class of cell-surface receptor -
CORRECT ANSWERS✅✅ion-channel-coupled receptors can rapidly alter the membrane
potential in response to signal binding
what is true of the GTP- binding proteins that act as molecular switches inside cells?
- they turn themselves on by phosphorylating GDP to form GTP
- they turn themselves on by hydrolyzing GTP to form GDP
- they are active when GDP is bound
- they are active only in their trimeric forms
- they are active when GTP is bound - CORRECT ANSWERS✅✅they are active when GTP
is bound
see pic on phone - CORRECT ANSWERS✅✅
see pic on phone - CORRECT ANSWERS✅✅
Which is true of the GTP-binding proteins that participate in intracellular signaling?
- only monomeric GTP-binding proteins relay messages from G-protein-coupled receptors
- only trimeric GTP-binding proteins participate in intracellular cell signaling
-only trimeric GTP-binding proteins relay messages from G-protein- coupled receptors
- G-protein-couples receptors interact with all types of GTP-binding proteins
-only trimeric GTP-binding proteins interact with guanine nucleotide exchange factors
(GEFs) - CORRECT ANSWERS✅✅only trimeric GTP-binding proteins relay messages
from G-proteins-coupled receptors
Mutations in genes encoding cell signaling proteins contribute to many cancers. For example,
a chromosomal translocation fuses the Bcr gene to the Abl gene, leading to a constitutively
active Bcr-Abl kinase and chronic myeloid leukemia (CML). CML is successfully treated
with the drug imatinib (trade name Gleevec), which mimics an Abl kinase substrate and thus
AND CORRECT ANSWERS
assignment 5 - CORRECT ANSWERS✅✅
Many of the extracellular signal molecules that regulate inflammation are released locally at
the site of infection. What form of cell-cell signaling is being used?
paracrine
endocrine
neuronal
contact-dependent - CORRECT ANSWERS✅✅paracrine
What does a target cell require to respond to an extracellular signal molecule?
- effector molecules that alter cell behavior in response to the signal molecule
- appropriate intracellular signaling pathways
-access to the signal molecule
-the appropriate machinery to produce and secrete the signal molecule
- a receptor that recognizes the signal molecule - CORRECT ANSWERS✅✅all except... the
appropriate machinery
Which statement about cell signaling is correct?
- each receptor triggers one particular type of cell behavior, for example, activating gene
expression
- all extracellular signal molecules act by binding to receptors on the cell surface
- all cell types are able to respond to the same set of signal molecules
- each receptor is generally activated by only one type of signal molecule
- each type of extracellular signal molecule induces the same response in all target cells -
CORRECT ANSWERS✅✅each receptor is generally activated by only one type of signal
molecule
What makes it possible for a combination of signal molecules to evoke a response that differs
from the sum of the effects that each signal could trigger on its own?
,- the tendency of different cells to display different receptors
- the ability of different intracellular relay systems to interact
- the ability of different signal molecules to bind to the same receptor
- the ability of the same signal molecule to bind to different receptors
- the ability of different receptors to activate different intracellular relay systems - CORRECT
ANSWERS✅✅the ability of different intracellular relay systems to interact
Under what condition will a target cell always respond quickly to an extracellular signal?
- the response relies on second messengers
- the signal molecules binds to an intracellular receptor
- the signal molecule is small
- the response does not require changes in gene expression
- the signal molecule is present in high concentrations - CORRECT ANSWERS✅✅the
response does not require changes in gene expression
Which of the following signaling pathways would be likely to trigger the most rapid cell
response?
- Acetylcholine binds to anion-channel-coupled receptor that allows Na+ to flow down its
electrochemical gradient, triggering contraction of a skeletal muscle cell.
- Adrenaline binds to a GPCR to activate a cyclic AMP signaling pathway that triggers the
synthesis of hormones in endocrine cells.
- Platelet-derived growth factor binds to a receptor tyrosine kinase to activate a signaling
pathway that stimulates cell proliferation at the site of a wound.
- Nerve growth factor binds to a receptor tyrosine kinase to activate a signaling pathway that
enhances the transcription of Bcl2, a protein that suppresses cell death.
- Adrenaline binds to a GPCR to activate a cyclic AMP signaling pathway that triggers
glycogen breakdown. - CORRECT ANSWERS✅✅Acetylcholine binds to anion-channel-
coupled receptor that allows Na+ to flow down its electrochemical gradient, triggering
contraction of a skeletal muscle cell
Which of the following statements is true?
- G-protein-coupled receptors are GTP-binding proteins
- all enzyme-coupled receptors have an intrinsic catalytic domain on the cytosolic side of the
plasma membrane
, - many ion-channel-coupled receptors have an intrinsic catalytic domain on the cytosolic side
of the plasma membrane
- ion-channel-coupled receptors can rapidly alter the membrane potential in response to signal
binding
- each extracellular signal molecule interacts with a single class of cell-surface receptor -
CORRECT ANSWERS✅✅ion-channel-coupled receptors can rapidly alter the membrane
potential in response to signal binding
what is true of the GTP- binding proteins that act as molecular switches inside cells?
- they turn themselves on by phosphorylating GDP to form GTP
- they turn themselves on by hydrolyzing GTP to form GDP
- they are active when GDP is bound
- they are active only in their trimeric forms
- they are active when GTP is bound - CORRECT ANSWERS✅✅they are active when GTP
is bound
see pic on phone - CORRECT ANSWERS✅✅
see pic on phone - CORRECT ANSWERS✅✅
Which is true of the GTP-binding proteins that participate in intracellular signaling?
- only monomeric GTP-binding proteins relay messages from G-protein-coupled receptors
- only trimeric GTP-binding proteins participate in intracellular cell signaling
-only trimeric GTP-binding proteins relay messages from G-protein- coupled receptors
- G-protein-couples receptors interact with all types of GTP-binding proteins
-only trimeric GTP-binding proteins interact with guanine nucleotide exchange factors
(GEFs) - CORRECT ANSWERS✅✅only trimeric GTP-binding proteins relay messages
from G-proteins-coupled receptors
Mutations in genes encoding cell signaling proteins contribute to many cancers. For example,
a chromosomal translocation fuses the Bcr gene to the Abl gene, leading to a constitutively
active Bcr-Abl kinase and chronic myeloid leukemia (CML). CML is successfully treated
with the drug imatinib (trade name Gleevec), which mimics an Abl kinase substrate and thus
