Question 1

Acetylcholine is a neurotransmitter that stimulates muscle contraction. Acetylcholine is acting as a(n)

Accepted Answer

A)  endocrine signal. 
B)  paracrine signal. 
C)  autocrine signal. 
D)  second messenger. 
A)  endocrine signal. 
B)  paracrine signal. 
C)  autocrine signal. 
D)  second messenger.

Question 2

What is a protein that promotes GDP-GTP exchange in G proteins known as?

Accepted Answer

Guanine nu

Question 3

A ligand binds to a transmembrane protein. This causes a conformational change in the protein that is detected by an intracellular protein. The intracellular protein is an enzyme that adds phosphate groups to target proteins. The phosphorylated proteins cause a physiological change within the cell. This is an example of

Accepted Answer

A)  a metabolic pathway. 
B)  homeostasis. 
C)  a signal transduction pathway. 
D)  an allosteric inhibition pathway. 
A)  a metabolic pathway. 
B)  homeostasis. 
C)  a signal transduction pathway. 
D)  an allosteric inhibition pathway.

Question 4

On binding of an insulin molecule to the insulin receptor, which region of the receptor becomes phosphorylated?

Accepted Answer

A)  CR 
B)  TM 
C)  TK 
D)  L1 
A)  CR 
B)  TM 
C)  TK 
D)  L1

Question 5

Which of the following list includes ONLY first messengers?

Accepted Answer

A)  cortisol, insulin, prostaglandins 
B)  nitric oxide, estradiol, heme 
C)  insulin, glucagon, glucose 
D)  Ca2+, testosterone, protein kinase A 
A)  cortisol, insulin, prostaglandins 
B)  nitric oxide, estradiol, heme 
C)  insulin, glucagon, glucose 
D)  Ca2+, testosterone, protein kinase A

Question 6

The PI-3K signaling pathway is activated by the binding of to its receptor. This
leads to an increase in glucose uptake and in synthesis.

Accepted Answer

The answer of The PI-3K signaling pathway is activated by...

Question 7

Which of the following is NOT an expected effect of the binding of the glucocorticoid response element by GR?

Accepted Answer

A)  upregulation of annexin I 
B)  inhibition of the inflammatory response 
C)  upregulation of cyclooxygenase-2 
D)  decreased interaction of p65 and p50 of NF$\kappa$B 
A)  upregulation of annexin I 
B)  inhibition of the inflammatory response 
C)  upregulation of cyclooxygenase-2 
D)  decreased interaction of p65 and p50 of NF$\kappa$B

Question 8

The PPAR$\gamma$-RXR$\alpha$ heterodimer interacts with DNA via

Accepted Answer

A)  the LXXLL sequences. 
B)  leucine zipper motifs. 
C)  zinc finger motifs. 
D)  basic leucine zipper motifs. 
A)  the LXXLL sequences. 
B)  leucine zipper motifs. 
C)  zinc finger motifs. 
D)  basic leucine zipper motifs.

Question 9

The __________ is a specific type of _.

Accepted Answer

A)  "GRK; $\beta$ARK" 
B)  "$\beta$-adrenergic receptor kinase; $\beta$-arrestin" 
C)  "regulator of G protein signaling; GTPase activating protein" 
D)  "GTPase activating protein; guanine nucleotide exchange factor" 
A)  "GRK; $\beta$ARK" 
B)  "$\beta$-adrenergic receptor kinase; $\beta$-arrestin" 
C)  "regulator of G protein signaling; GTPase activating protein" 
D)  "GTPase activating protein; guanine nucleotide exchange factor"

Question 10

Cyclic GMP is the during vasodilation.

Accepted Answer

A)  first messenger 
B)  second messenger 
C)  paracrine signal 
D)  activator of nitric oxide synthetase 
A)  first messenger 
B)  second messenger 
C)  paracrine signal 
D)  activator of nitric oxide synthetase

Question 11

Caspase 3 is responsible for

Accepted Answer

A)  activating caspase 8. 
B)  phosphorylating Fas. 
C)  degrading key regulatory molecules. 
D)  dephosphorylating FasL. 
A)  activating caspase 8. 
B)  phosphorylating Fas. 
C)  degrading key regulatory molecules. 
D)  dephosphorylating FasL.

Question 12

The insulin receptor is a type of

Accepted Answer

A)  G protein-linked receptor. 
B)  receptor tyrosine kinase. 
C)  oncogene. 
D)  MEK. 
A)  G protein-linked receptor. 
B)  receptor tyrosine kinase. 
C)  oncogene. 
D)  MEK.

Question 13

Which of the following does NOT participate in a signal transduction pathway?

Accepted Answer

A)  second messenger 
B)  first messenger 
C)  receptor protein 
D)  lipid transporter 
A)  second messenger 
B)  first messenger 
C)  receptor protein 
D)  lipid transporter

Question 14

Phosphorylation of which of the following is necessary for the increased expression of antiapoptotic genes?

Accepted Answer

A)  RIP 
B)  TNF receptor 
C)  FADD 
D)  IKK 
A)  RIP 
B)  TNF receptor 
C)  FADD 
D)  IKK

Question 15

Which of the following is a metabolite receptor?

Accepted Answer

A)  aldosterone receptor 
B)  glucocorticoid receptor 
C)  progesterone receptor 
D)  thyroid hormone receptor 
A)  aldosterone receptor 
B)  glucocorticoid receptor 
C)  progesterone receptor 
D)  thyroid hormone receptor

Question 16

Compare and contrast the pseudosubstrate found in the regulatory subunit of protein kinase A with a substrate of protein kinase A.

Accepted Answer

Substrates of protein kinase A contain a

Question 17

Activation of caspases ultimately leads to the programmed death of the cell. What is this process known as? Explain why this may be a beneficial outcome to the organism.

Accepted Answer

Apoptosis. Apoptosis is advant

Question 18

Which of the following occurs after activation of the PI-3K signaling pathway?

Accepted Answer

A)  Glycogen synthesis rates decrease. 
B)  GRB2 is activated. 
C)  GLUT-1 levels decrease. 
D)  Glucose uptake increases. 
A)  Glycogen synthesis rates decrease. 
B)  GRB2 is activated. 
C)  GLUT-1 levels decrease. 
D)  Glucose uptake increases.

Question 19

Cell-specific responses to signaling molecules are possible because

Accepted Answer

A)  nuclear receptor expression is cell specific. 
B)  target palindromic DNA sequences are ubiquitous. 
C)  signaling molecules are hydrophobic and can pass through the plasma membrane. 
D)  only some cells express gated channels for the signaling molecules. 
A)  nuclear receptor expression is cell specific. 
B)  target palindromic DNA sequences are ubiquitous. 
C)  signaling molecules are hydrophobic and can pass through the plasma membrane. 
D)  only some cells express gated channels for the signaling molecules.

Question 20

GRB2 contains both SH2 and SH3 domains. Contrast the role of each domain in the function of GRB2.

Accepted Answer

The SH2 domain of GRB2 identif

Exam 8: Cell Signaling Systems

Acetylcholine is a neurotransmitter that stimulates muscle contraction. Acetylcholine is acting as a(n)

What is a protein that promotes GDP-GTP exchange in G proteins known as?

On binding of an insulin molecule to the insulin receptor, which region of the receptor becomes phosphorylated?

Which of the following list includes ONLY first messengers?

The PI-3K signaling pathway is activated by the binding of to its receptor. This leads to an increase in glucose uptake and in synthesis.

Which of the following is NOT an expected effect of the binding of the glucocorticoid response element by GR?

The PPAR γ\gammaγ -RXR α\alphaα heterodimer interacts with DNA via

The __________ is a specific type of _.

Cyclic GMP is the during vasodilation.

Caspase 3 is responsible for

The insulin receptor is a type of

Which of the following does NOT participate in a signal transduction pathway?

Phosphorylation of which of the following is necessary for the increased expression of antiapoptotic genes?

Which of the following is a metabolite receptor?

Compare and contrast the pseudosubstrate found in the regulatory subunit of protein kinase A with a substrate of protein kinase A.

Activation of caspases ultimately leads to the programmed death of the cell. What is this process known as? Explain why this may be a beneficial outcome to the organism.

Which of the following occurs after activation of the PI-3K signaling pathway?

Cell-specific responses to signaling molecules are possible because

GRB2 contains both SH2 and SH3 domains. Contrast the role of each domain in the function of GRB2.

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

Filters

The PPAR $\gamma$ -RXR $\alpha$ heterodimer interacts with DNA via