Question 1

An example of signaling by direct cell-cell interactions is the

Accepted Answer

A)  Wingless (Wnt) signaling pathway. 
B)  JAK/STAT pathway. 
C)  Notch pathway. 
D)  pathway leading to vulval development in C. elegans. 
A)  Wingless (Wnt) signaling pathway. 
B)  JAK/STAT pathway. 
C)  Notch pathway. 
D)  pathway leading to vulval development in C. elegans. C

Question 2

A mutation that causes a G-protein to lose its ability to hydrolyze bound GTP would be expected to have constitutively

Accepted Answer

A)  inactive $\beta$$\gamma$subunits. 
B)  bound $\alpha$$\beta$$\gamma$subunits. 
C)  active $\alpha$ subunits. 
D)  inactive $\alpha$ subunits. 
A)  inactive $\beta$$\gamma$subunits. 
B)  bound $\alpha$$\beta$$\gamma$subunits. 
C)  active $\alpha$ subunits. 
D)  inactive $\alpha$ subunits. C

Question 3

The protein kinase Raf phosphorylates the protein kinase _______, which then phosphorylates (on both threonine and tyrosine residues) _______.

Accepted Answer

MEK; ERK (MAP kinase)

Question 4

The term "paracrine signaling" refers to

Accepted Answer

A)  signaling between cells located far from each other. 
B)  stimulation of a cell by substances produced by the cell itself. 
C)  signaling between cells located close to each other. 
D)  signaling between parenchyma cells. 
A)  signaling between cells located far from each other. 
B)  stimulation of a cell by substances produced by the cell itself. 
C)  signaling between cells located close to each other. 
D)  signaling between parenchyma cells.

Question 5

In plants, growth can be mediated by what is frequently referred to as "auxin-induced transcription" of genes critical to growth. This terminology was derived from experiments demonstrating that the addition of auxin leads to an increase in the expression of genes responsible for growth. However, since auxin is not a transcription factor and cannot directly activate transcription, how does it regulate gene activity?

Accepted Answer

Many plant growth genes are constitutive

Question 6

Hydrolysis of PIP2 by phospholipase C is stimulated by

Accepted Answer

A)  G protein-linked receptors. 
B)  protein-tyrosine kinase receptors. 
C)  serine-threonine kinase receptors. 
D)  both G protein-linked receptors and protein-tyrosine kinase receptors. 
A)  G protein-linked receptors. 
B)  protein-tyrosine kinase receptors. 
C)  serine-threonine kinase receptors. 
D)  both G protein-linked receptors and protein-tyrosine kinase receptors.

Question 7

A researcher generated a mutant SH2-containing protein such that it binds tyrosine and phosphotyrosine with equal affinity. As a result, MEK activity would be expected to

Accepted Answer

A)  increase with ligand binding-induced dimerization. 
B)  remain the same with receptor dimerization and autophosphorylation. 
C)  decrease due to changes in Raf activation. 
D)  decrease due to allosteric inhibition of SH2-domain binding. 
A)  increase with ligand binding-induced dimerization. 
B)  remain the same with receptor dimerization and autophosphorylation. 
C)  decrease due to changes in Raf activation. 
D)  decrease due to allosteric inhibition of SH2-domain binding.

Question 8

In plants, cytokinins stimulate

Accepted Answer

A)  cell division. 
B)  cell elongation. 
C)  cell enlargement. 
D)  fruit ripening. 
A)  cell division. 
B)  cell elongation. 
C)  cell enlargement. 
D)  fruit ripening.

Question 9

How would inhibition of PI 3-kinase affect ERK activity in a growth
Factor-stimulated cell?

Accepted Answer

A)  ERK activity would be inhibited. 
B)  ERK activity would be unaffected. 
C)  ERK activity would be upregulated. 
D)  ERK protein would be targeted for destruction by proteolysis. 
A)  ERK activity would be inhibited. 
B)  ERK activity would be unaffected. 
C)  ERK activity would be upregulated. 
D)  ERK protein would be targeted for destruction by proteolysis.

Question 10

Which of the following would lead to a termination of Wnt signaling?

Accepted Answer

A)  Phosphorylation of Disheveled 
B)  Inactivation of the destruction complex 
C)  Phosphorylation of $\beta$-catenin 
D)  Activation of Tcf 
A)  Phosphorylation of Disheveled 
B)  Inactivation of the destruction complex 
C)  Phosphorylation of $\beta$-catenin 
D)  Activation of Tcf

Question 11

MEK is a protein kinase that phosphorylates _______ residues.

Accepted Answer

A)  threonine and tyrosine 
B)  tyrosine 
C)  histidine 
D)  arginine and lysine 
A)  threonine and tyrosine 
B)  tyrosine 
C)  histidine 
D)  arginine and lysine

Question 12

_______ refers to the interaction of one signaling pathway with another and integrates the activities of different pathways within the cell.

Accepted Answer

The answer of _______ refers to the interaction of one...

Question 13

Wnt is a signal molecule that binds to Frizzled/LRP, activating Dishevelled to inhibit a protein kinase. This results in longer lived $\beta$-catenin, which enters the nucleus and turns on target genes.

Accepted Answer

A) True 
 B)False

Question 14

Nitric oxide is a signal molecule that can

Accepted Answer

A)  bind to surface receptors and activate second messengers. 
B)  bind to surface receptors and open ion channels. 
C)  diffuse across cell membranes and bind to receptors that regulate transcription. 
D)  diffuse across cell membranes and directly alter the activity of intracellular enzymes. 
A)  bind to surface receptors and activate second messengers. 
B)  bind to surface receptors and open ion channels. 
C)  diffuse across cell membranes and bind to receptors that regulate transcription. 
D)  diffuse across cell membranes and directly alter the activity of intracellular enzymes.

Question 15

Protein kinase A regulates glycogen metabolism by phosphorylating glycogen synthase and

Accepted Answer

A)  phosphorylase kinase. 
B)  glycogen phosphatase. 
C)  glycogen phosphorylase. 
D)  glucokinase. 
A)  phosphorylase kinase. 
B)  glycogen phosphatase. 
C)  glycogen phosphorylase. 
D)  glucokinase.

Question 16

A major function of cAMP in animal cells is to activate

Accepted Answer

A)  adenylyl cyclase. 
B)  protein kinase A. 
C)  protein kinase C. 
D)  tyrosine kinases. 
A)  adenylyl cyclase. 
B)  protein kinase A. 
C)  protein kinase C. 
D)  tyrosine kinases.

Question 17

Why is it important that neurotransmitters receptors be located on the external surface of cells?

Accepted Answer

Neurotransmitters are hydrophi

Question 18

What would happen to NF-$\kappa$B signaling if I$\kappa$B were unable to be dephosphorylated?

Accepted Answer

Most likely nothing. When I@#LAT-DLM&B is phosphor

Question 19

What are the first three steps in signaling from cytokine receptors?

Accepted Answer

(1) Receptor dimerization, (2)

Question 20

Explain the concept of "feedback loops" in signaling networks.

Accepted Answer

Feedback loops allow for a form of autor

An example of signaling by direct cell-cell interactions is the

A mutation that causes a G-protein to lose its ability to hydrolyze bound GTP would be expected to have constitutively

The protein kinase Raf phosphorylates the protein kinase _, which then phosphorylates (on both threonine and tyrosine residues) _.

The term "paracrine signaling" refers to

Hydrolysis of PIP₂ by phospholipase C is stimulated by

A researcher generated a mutant SH2-containing protein such that it binds tyrosine and phosphotyrosine with equal affinity. As a result, MEK activity would be expected to

In plants, cytokinins stimulate

How would inhibition of PI 3-kinase affect ERK activity in a growth Factor-stimulated cell?

Which of the following would lead to a termination of Wnt signaling?

MEK is a protein kinase that phosphorylates _______ residues.

_______ refers to the interaction of one signaling pathway with another and integrates the activities of different pathways within the cell.

Wnt is a signal molecule that binds to Frizzled/LRP, activating Dishevelled to inhibit a protein kinase. This results in longer lived $\beta$ -catenin, which enters the nucleus and turns on target genes.

Nitric oxide is a signal molecule that can

Protein kinase A regulates glycogen metabolism by phosphorylating glycogen synthase and

A major function of cAMP in animal cells is to activate

Why is it important that neurotransmitters receptors be located on the external surface of cells?

What would happen to NF- $\kappa$ B signaling if I $\kappa$ B were unable to be dephosphorylated?

What are the first three steps in signaling from cytokine receptors?

Explain the concept of "feedback loops" in signaling networks.

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

Exam 17: Cell Signaling

An example of signaling by direct cell-cell interactions is the

A mutation that causes a G-protein to lose its ability to hydrolyze bound GTP would be expected to have constitutively

The protein kinase Raf phosphorylates the protein kinase _______, which then phosphorylates (on both threonine and tyrosine residues) _______.

The term "paracrine signaling" refers to

Hydrolysis of PIP2 by phospholipase C is stimulated by

A researcher generated a mutant SH2-containing protein such that it binds tyrosine and phosphotyrosine with equal affinity. As a result, MEK activity would be expected to

In plants, cytokinins stimulate

How would inhibition of PI 3-kinase affect ERK activity in a growth Factor-stimulated cell?

Which of the following would lead to a termination of Wnt signaling?

MEK is a protein kinase that phosphorylates _______ residues.

_______ refers to the interaction of one signaling pathway with another and integrates the activities of different pathways within the cell.

Wnt is a signal molecule that binds to Frizzled/LRP, activating Dishevelled to inhibit a protein kinase. This results in longer lived β\betaβ -catenin, which enters the nucleus and turns on target genes.

Nitric oxide is a signal molecule that can

Protein kinase A regulates glycogen metabolism by phosphorylating glycogen synthase and

A major function of cAMP in animal cells is to activate

Why is it important that neurotransmitters receptors be located on the external surface of cells?

What would happen to NF- κ\kappaκ B signaling if I κ\kappaκ B were unable to be dephosphorylated?

What are the first three steps in signaling from cytokine receptors?

Explain the concept of "feedback loops" in signaling networks.

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 protein kinase Raf phosphorylates the protein kinase _, which then phosphorylates (on both threonine and tyrosine residues) _.

Hydrolysis of PIP₂ by phospholipase C is stimulated by

Wnt is a signal molecule that binds to Frizzled/LRP, activating Dishevelled to inhibit a protein kinase. This results in longer lived $\beta$ -catenin, which enters the nucleus and turns on target genes.

What would happen to NF- $\kappa$ B signaling if I $\kappa$ B were unable to be dephosphorylated?