Question 1

In what ways are steroid hormone receptors different from most other types of cellular receptors?

Accepted Answer

Most cellular receptors span the plasma

Question 2

The RAS guanine nucleotide-binding protein is activated by

Accepted Answer

A)  cAMP binding. 
B)  serine phosphorylation by protein kinase A. 
C)  GDP binding. 
D)  GTP binding. 
A)  cAMP binding. 
B)  serine phosphorylation by protein kinase A. 
C)  GDP binding. 
D)  GTP binding.

Question 3

Key targets of the JAK kinases are _______ proteins.

Accepted Answer

The answer of Key targets of the JAK kinases are...

Question 4

The TGF-$\beta$Smad pathway is similar to JAK/STAT signaling in that a protein kinase associated with a receptor directly phosphorylates and activates a transcription factor. However, the receptors for transforming growth factor beta (TGF-$\beta$) and related polypeptides are protein kinases that phosphorylate _______, rather than _______, residues on their substrate proteins.

Accepted Answer

A)  serine or threonine; tyrosine 
B)  tyrosine; serine or threonine 
C)  proline or aspartate; tyrosine 
D)  tryptophan; tyrosine 
A)  serine or threonine; tyrosine 
B)  tyrosine; serine or threonine 
C)  proline or aspartate; tyrosine 
D)  tryptophan; tyrosine

Question 5

In plant cells, which signaling molecule induces cell elongation?

Accepted Answer

A)  Acetylcholine. 
B)  $\gamma$-aminobutyric acid (GAB
A) . 
C)  Auxin. 
D)  Retinoic acid. 
A)  Acetylcholine. 
B)  $\gamma$-aminobutyric acid (GAB
A) . 
C)  Auxin. 
D)  Retinoic acid.

Question 6

Which molecule stimulates fibroblasts to proliferate and thus heal a wound?

Accepted Answer

A)  EGF 
B)  NGF 
C)  NO 
D)  PDGF 
A)  EGF 
B)  NGF 
C)  NO 
D)  PDGF

Question 7

The mTOR pathway is a central regulator of cell growth that couples the control of

Accepted Answer

A)  protein synthesis to the availability of growth factors, nutrients,
And energy. 
B)  DNA replication during mitosis and during meiosis. 
C)  transcription factors that regulate gene expression in the liver. 
D)  transcription factors that regulate gene expression in early embryonic development. 
A)  protein synthesis to the availability of growth factors, nutrients,
And energy. 
B)  DNA replication during mitosis and during meiosis. 
C)  transcription factors that regulate gene expression in the liver. 
D)  transcription factors that regulate gene expression in early embryonic development.

Question 8

The extensive crosstalk between individual signal transduction pathways means that multiple pathways interact with one another to form _______ within the cell.

Accepted Answer

The answer of The extensive crosstalk between individual signal transduction...

Question 9

Protein kinase A is activated by

Accepted Answer

A)  phosphorylation of its catalytic subunit. 
B)  phosphorylation of its regulatory subunits. 
C)  binding of cAMP to its catalytic subunits. 
D)  binding of cAMP to its regulatory subunits. 
A)  phosphorylation of its catalytic subunit. 
B)  phosphorylation of its regulatory subunits. 
C)  binding of cAMP to its catalytic subunits. 
D)  binding of cAMP to its regulatory subunits.

Question 10

Most of the effects of cyclic AMP (cAMP) in the cell are mediated by

Accepted Answer

A)  protein kinase A. 
B)  ion channels. 
C)  protein kinase C. 
D)  cAMP phosphodiesterase. 
A)  protein kinase A. 
B)  ion channels. 
C)  protein kinase C. 
D)  cAMP phosphodiesterase.

Question 11

The medical usage of nitroglycerine in heart disease is based on its

Accepted Answer

A)  inhibition of adenylate cyclase and blood vessel contraction. 
B)  conversion to NO and blood vessel dilation. 
C)  activation of NO-synthase and muscle cell contraction. 
D)  promotion of cyclooxygenase and prostaglandin synthesis. 
A)  inhibition of adenylate cyclase and blood vessel contraction. 
B)  conversion to NO and blood vessel dilation. 
C)  activation of NO-synthase and muscle cell contraction. 
D)  promotion of cyclooxygenase and prostaglandin synthesis.

Question 12

The ras gene is mutant in about 25% of all human cancers. When ras is mutant, it typically remains active in mitogenic signal transduction because it is unable to _______ GTP.

Accepted Answer

The answer of The ras gene is mutant in about...

Question 13

In an active state of a G protein, the

Accepted Answer

A)  $\alpha$ subunit binds to a target protein, and the $\beta$$\gamma$ subunit remains bound to the receptor. 
B)  $\alpha$ and $\beta$$\gamma$subunits both can bind to target proteins. 
C)  $\alpha$$\beta$ and $\gamma$subunits both can bind to target proteins. 
D)  $\gamma$ subunit can bind to a target protein, and the $\alpha$$\beta$subunit remains bound to the receptor. 
A)  $\alpha$ subunit binds to a target protein, and the $\beta$$\gamma$ subunit remains bound to the receptor. 
B)  $\alpha$ and $\beta$$\gamma$subunits both can bind to target proteins. 
C)  $\alpha$$\beta$ and $\gamma$subunits both can bind to target proteins. 
D)  $\gamma$ subunit can bind to a target protein, and the $\alpha$$\beta$subunit remains bound to the receptor.

Question 14

Signaling by the steroid hormone estrogen is an example of _______ signaling.

Accepted Answer

A)  autocrine 
B)  endocrine 
C)  paracrine 
D)  direct cell-to-cell 
A)  autocrine 
B)  endocrine 
C)  paracrine 
D)  direct cell-to-cell

Question 15

Statins, a class of drugs that are often administered to patients with high cholesterol, inhibit the biosynthesis of cholesterol. Statin drugs would not be expected to affect the biosynthetic pathway of which of the following signal molecules?

Accepted Answer

A)  Thyroid hormone 
B)  Vitamin D3 
C)  Retinoic acid 
D)  Estrogen 
A)  Thyroid hormone 
B)  Vitamin D3 
C)  Retinoic acid 
D)  Estrogen

Question 16

Heterotrimeric G proteins are not the only guanine nucleotide-binding proteins. Which of the following represents a family of GTP-binding proteins that act as monomers rather than heterotrimeric compounds?

Accepted Answer

A)  Ras 
B)  ERK 
C)  Raf 
D)  Smad 
A)  Ras 
B)  ERK 
C)  Raf 
D)  Smad

Question 17

The second messenger, phosphatidylinositol 3,4,5-trisphosphate (PIP3) is generated by the action of the enzyme _______ on phosphatidylinositol 4,5-bisphosphate (PIP2).

Accepted Answer

A)  protein kinase A 
B)  protein kinase C 
C)  phosphatidylinositide (PI) 3-kinase 
D)  mTOR kinase 
A)  protein kinase A 
B)  protein kinase C 
C)  phosphatidylinositide (PI) 3-kinase 
D)  mTOR kinase

Question 18

G protein-coupled receptors are important molecules involved in signal transduction. Which statement about G protein-coupled receptors is true?

Accepted Answer

A)  They are activated only by steroid hormones. 
B)  They bind only guanine nucleotides. 
C)  They bind both adenine and guanine nucleotides. 
D)  They generally contain seven membrane-spanning $\alpha$helices. 
A)  They are activated only by steroid hormones. 
B)  They bind only guanine nucleotides. 
C)  They bind both adenine and guanine nucleotides. 
D)  They generally contain seven membrane-spanning $\alpha$helices.

Question 19

Which statement regarding heterotrimeric G proteins in a resting state is true?

Accepted Answer

A)  GDP is bound to the $\beta$subunit in a complex with both the $\alpha$ and $\gamma$subunits. 
B)  GDP is bound to the $\alpha$subunit in a complex with both the $\beta$ and $\gamma$subunits. 
C)  GTP is bound to the $\alpha$ subunit in a complex with both the $\beta$and $\gamma$ subunits. 
D)  The proteins are in a complex with G protein-coupled receptors. 
A)  GDP is bound to the $\beta$subunit in a complex with both the $\alpha$ and $\gamma$subunits. 
B)  GDP is bound to the $\alpha$subunit in a complex with both the $\beta$ and $\gamma$subunits. 
C)  GTP is bound to the $\alpha$ subunit in a complex with both the $\beta$and $\gamma$ subunits. 
D)  The proteins are in a complex with G protein-coupled receptors.

Question 20

NF-$\kappa$B can activate genes during the immune response by a protein kinase that

Accepted Answer

A)  phosphorylates the transcription factor NF-$\kappa$B to activate it. 
B)  phosphorylates the inhibitory factor I$\kappa$B, causing it to be degraded and to release NF-$\kappa$B. 
C)  phosphorylates a MAP kinase to initiate its cascade. 
D)  activates a phosphorylase that removes an inhibiting phosphate from the NF-$\kappa$B. 
A)  phosphorylates the transcription factor NF-$\kappa$B to activate it. 
B)  phosphorylates the inhibitory factor I$\kappa$B, causing it to be degraded and to release NF-$\kappa$B. 
C)  phosphorylates a MAP kinase to initiate its cascade. 
D)  activates a phosphorylase that removes an inhibiting phosphate from the NF-$\kappa$B.

In what ways are steroid hormone receptors different from most other types of cellular receptors?

The RAS guanine nucleotide-binding protein is activated by

Key targets of the JAK kinases are _______ proteins.

In plant cells, which signaling molecule induces cell elongation?

Which molecule stimulates fibroblasts to proliferate and thus heal a wound?

The mTOR pathway is a central regulator of cell growth that couples the control of

The extensive crosstalk between individual signal transduction pathways means that multiple pathways interact with one another to form _______ within the cell.

Protein kinase A is activated by

Most of the effects of cyclic AMP (cAMP) in the cell are mediated by

The medical usage of nitroglycerine in heart disease is based on its

The ras gene is mutant in about 25% of all human cancers. When ras is mutant, it typically remains active in mitogenic signal transduction because it is unable to _______ GTP.

In an active state of a G protein, the

Signaling by the steroid hormone estrogen is an example of _______ signaling.

Statins, a class of drugs that are often administered to patients with high cholesterol, inhibit the biosynthesis of cholesterol. Statin drugs would not be expected to affect the biosynthetic pathway of which of the following signal molecules?

Heterotrimeric G proteins are not the only guanine nucleotide-binding proteins. Which of the following represents a family of GTP-binding proteins that act as monomers rather than heterotrimeric compounds?

The second messenger, phosphatidylinositol 3,4,5-trisphosphate (PIP₃) is generated by the action of the enzyme _______ on phosphatidylinositol 4,5-bisphosphate (PIP₂).

G protein-coupled receptors are important molecules involved in signal transduction. Which statement about G protein-coupled receptors is true?

Which statement regarding heterotrimeric G proteins in a resting state is true?

NF- $\kappa$ B can activate genes during the immune response by a protein kinase that

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

Protein Synthesis, Processing, and Regulation

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

The Cell Cycle

Cell Death and Cell Renewal

Cancer

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Exam 17: Cell Signaling

In what ways are steroid hormone receptors different from most other types of cellular receptors?

The RAS guanine nucleotide-binding protein is activated by

Key targets of the JAK kinases are _______ proteins.

In plant cells, which signaling molecule induces cell elongation?

Which molecule stimulates fibroblasts to proliferate and thus heal a wound?

The mTOR pathway is a central regulator of cell growth that couples the control of

The extensive crosstalk between individual signal transduction pathways means that multiple pathways interact with one another to form _______ within the cell.

Protein kinase A is activated by

Most of the effects of cyclic AMP (cAMP) in the cell are mediated by

The medical usage of nitroglycerine in heart disease is based on its

The ras gene is mutant in about 25% of all human cancers. When ras is mutant, it typically remains active in mitogenic signal transduction because it is unable to _______ GTP.

In an active state of a G protein, the

Signaling by the steroid hormone estrogen is an example of _______ signaling.

Statins, a class of drugs that are often administered to patients with high cholesterol, inhibit the biosynthesis of cholesterol. Statin drugs would not be expected to affect the biosynthetic pathway of which of the following signal molecules?

Heterotrimeric G proteins are not the only guanine nucleotide-binding proteins. Which of the following represents a family of GTP-binding proteins that act as monomers rather than heterotrimeric compounds?

The second messenger, phosphatidylinositol 3,4,5-trisphosphate (PIP3) is generated by the action of the enzyme _______ on phosphatidylinositol 4,5-bisphosphate (PIP2).

G protein-coupled receptors are important molecules involved in signal transduction. Which statement about G protein-coupled receptors is true?

Which statement regarding heterotrimeric G proteins in a resting state is true?

NF- κ\kappaκ B can activate genes during the immune response by a protein kinase that

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

Protein Synthesis, Processing, and Regulation

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

The second messenger, phosphatidylinositol 3,4,5-trisphosphate (PIP₃) is generated by the action of the enzyme _______ on phosphatidylinositol 4,5-bisphosphate (PIP₂).

NF- $\kappa$ B can activate genes during the immune response by a protein kinase that