Question 1

Matching

-The gland that is predominately responsible for producing the hormone that is released in response to consumption of a meal particularly high in carbohydrates.

Accepted Answer

A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK) 
A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK)

Question 2

Which of the following best describe the mechanism of calmodulin (CaM)mediated activation?

Accepted Answer

A) Ca2+ binding to calmodulin (CaM)results in conformational change that exposes a hydrophobic patch capable of binding to calcium sensitive protein kinase 
B) a conformational change induced by the binding of Ca2+ results in the release of the phosphate group in calmodulin (CaM) 
C) calmodulin (CaM)sensitive protein kinase dimerizes forming a joint active site capable of tightly binding Ca2+ 
D) phosphorylation of a tyrosine on calmodulin induced a conformational change that results in release of Ca2+ from the cytosol. 
E) none of the above. 
A) Ca2+ binding to calmodulin (CaM)results in conformational change that exposes a hydrophobic patch capable of binding to calcium sensitive protein kinase 
B) a conformational change induced by the binding of Ca2+ results in the release of the phosphate group in calmodulin (CaM) 
C) calmodulin (CaM)sensitive protein kinase dimerizes forming a joint active site capable of tightly binding Ca2+ 
D) phosphorylation of a tyrosine on calmodulin induced a conformational change that results in release of Ca2+ from the cytosol. 
E) none of the above.

Question 3

Anthrax toxin functions by altering levels of cAMP.The toxin also contains an edema factor,which requires the activity of calmodulin (CaM)for proper function.Based on this information,which of the following can you conclude?

Accepted Answer

A) The toxin alters cAMP dependent cell signaling. 
B) Calcium levels affect the function of the edema factor. 
C) Unlike other toxins,the anthrax toxin does not function by altering biochemical signaling. 
D) A and B 
E) A and C 
A) The toxin alters cAMP dependent cell signaling. 
B) Calcium levels affect the function of the edema factor. 
C) Unlike other toxins,the anthrax toxin does not function by altering biochemical signaling. 
D) A and B 
E) A and C

Question 4

Phospholipase C cleaves PIP2,resulting in an increased cytosolic concentration of
(I)IP3 (inositolpolyphosphate-3)
(II)protein kinase C
(III)cAMP
 IV.Ca2+

Accepted Answer

A) I only 
B) II only 
C) I,III 
D) I,IV 
E) IV only 
A) I only 
B) II only 
C) I,III 
D) I,IV 
E) IV only

Question 5

Matching

-Proteins that bind molecules and elicit a cellular response are called _____.

Accepted Answer

A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK) 
A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK)

Question 6

Which of the following is (are)an advantage(s)of protein phosphorylation in regards to biochemical signaling?
(I)Phosphorylation is rapid and specific.
(II)Phosphorylation is enzymatically reversible.
(III)Phosphorylation can be amplified by cascade systems.
(IV)Phosphorylation results in covalent modification of enzymes.

Accepted Answer

A) I,II,III,IV 
B) II,III,IV 
C) II,III 
D) I,II 
E) III only 
A) I,II,III,IV 
B) II,III,IV 
C) II,III 
D) I,II 
E) III only

Question 7

Autoinhibition in the SH2 and SH3 domains

Accepted Answer

A) occurs when a SH2 phospho-Tyr forms a salt bridge with an Arg on SH3. 
B) occurs when a SH2 phospho-Tyr binds a Pro segment on the SH3 domain,therefore blocking the active site and burying the required Tyr. 
C) occurs when a salt bride forms between the active site phosphor-Tyr on SH3 and the Glu on the activation loop. 
D) occurs when the salt bridge between Glu and Arg is broken. 
E) None of the above is correct. 
A) occurs when a SH2 phospho-Tyr forms a salt bridge with an Arg on SH3. 
B) occurs when a SH2 phospho-Tyr binds a Pro segment on the SH3 domain,therefore blocking the active site and burying the required Tyr. 
C) occurs when a salt bride forms between the active site phosphor-Tyr on SH3 and the Glu on the activation loop. 
D) occurs when the salt bridge between Glu and Arg is broken. 
E) None of the above is correct.

Question 8

Which of the following functions as a regulatory protein by dephosphorylating activated enzymes?

Accepted Answer

A) receptor tyrosine kinase 
B) phosphoprotein phosphatase 
C) heterotrimeric G protein phosphorylase 
D) guanine nucleotide exchange factor 
E) Sos protein 
A) receptor tyrosine kinase 
B) phosphoprotein phosphatase 
C) heterotrimeric G protein phosphorylase 
D) guanine nucleotide exchange factor 
E) Sos protein

Question 9

Matching

-The first G protein-coupled receptor (GPCR)to be structurally analyzed at the atomic level was _____.

Accepted Answer

A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK) 
A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK)

Question 10

Which of the following statements concerning the action of G proteins on adenylate cyclase is true?
(I)G proteins always serve to activate adenylate cyclase.
(II)G proteins always serve to inhibit adenylate cyclase.
(III)Some G proteins activate adenylate cyclase,while others inhibit it.
(IV)G proteins do not act on adenylate cyclase at all.

Accepted Answer

A) I only 
B) II,III 
C) I,III 
D) II only 
E) III only 
A) I only 
B) II,III 
C) I,III 
D) II only 
E) III only

Question 11

Somatostatin
(I)inhibits the release of insulin.
(II)inhibits the release of glucagon.
(III)stimulates the release of insulin.
(IV)stimulates the release of glucagon.

Accepted Answer

A) I only 
B) II only 
C) I and II 
D) III and IV 
E) IV only 
A) I only 
B) II only 
C) I and II 
D) III and IV 
E) IV only

Question 12

Which of the following is (are)associated with cAMP binding to cAMP-dependent protein kinase A?
(I)cAMP binds to the regulatory subunits.
(II)Tetrameric regulatory subunits and catalytic subunits dissociate.
(III)Catalytic subunits phosphorylate multiple targets with specific serine and threonine residues.
(IV)cAMP is membrane bound via phosphoinositol attachment.

Accepted Answer

A) I,II,III,IV 
B) I,II,III 
C) I,II 
D) II,III,IV 
E) III,IV 
A) I,II,III,IV 
B) I,II,III 
C) I,II 
D) II,III,IV 
E) III,IV

Question 13

Matching

-Isoproterenol functions as an agonist for receptors that bind hormones synthesized in the ___.

Accepted Answer

A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK) 
A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK)

Question 14

Matching

-A release of _____ would result in the stimulation of the liver to synthesize glycogen.

Accepted Answer

A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK) 
A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK)

Question 15

Heterotrimeric G proteins
(I)consist of three subunits,G$\alpha$,G$\beta$,and G$\gamma$.
(II)function as an autoinhibtory segment.
(III)can function as a mediator to adenylate cyclase activity.
(IV)are anchored to the cytoplasmic side of the membrane.

Accepted Answer

A) I,II,IV 
B) I,III,IV 
C) I,IV 
D) I,III 
E) I only 
A) I,II,IV 
B) I,III,IV 
C) I,IV 
D) I,III 
E) I only

Question 16

Matching

-The ____ signaling pathway relies on GTP dependent hydrolysis for subsequent synthesis of cAMP.

Accepted Answer

A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK) 
A)  receptors 
B)  phosphoinositide 
C)  rhodopsin 
D)  calmodulin 
E)  insulin
F) hypothalamus
G) cortisol
H) adrenal cortex
I) cyclic AMP
J) RasGAP
K) islets of Langerhans
L) adenylate cyclase (A
C) 
M) receptor tyrosine kinase (RTK)

Question 17

Which of the following activities would lead to a decrease in the level of IP3 in the cytosol?

Accepted Answer

A) increased activity of inositol polyphosphate 5-phosphatase 
B) increased activity of phospholipase C 
C) increased activation of protein kinase C 
D) increased Ca2+ concentration 
E) all of the above 
A) increased activity of inositol polyphosphate 5-phosphatase 
B) increased activity of phospholipase C 
C) increased activation of protein kinase C 
D) increased Ca2+ concentration 
E) all of the above

Question 18

Which of the following is (are)the result of insulin binding to its receptor?
(I)MAPK activation,which regulates gene expression via Fos,Jun and Myc.
(II)PI3K activation leading to an increase in glucose transport.
(III)High affinity binding of SH2 domains to phosphorylated tyrosines.
(IV)Autophosphorylation resulting in activation of tyrosine kinase.

Accepted Answer

A) II,III,IV 
B) I,II,III,IV 
C) II,III 
D) I,II 
E) III only 
A) II,III,IV 
B) I,II,III,IV 
C) II,III 
D) I,II 
E) III only

Question 19

Insulin binds to a receptor that
(I)is coupled to a G protein.
(II)possesses tyrosine kinase activity.
(III)possesses serine/threonine phosphatase activity.
(IV)interact with proteins homologous to Src

Accepted Answer

A) I,II,III 
B) II only 
C) I,III 
D) II,IV 
E) I,IV 
A) I,II,III 
B) II only 
C) I,III 
D) II,IV 
E) I,IV

Question 20

Cancer causing viruses often contain:
(I)oncogenes.
(II)genes encoding variant proteins.
(III)genes encoding cell proliferation inhibitors.
(IV)genes capable of inducing malignant transformation.

Accepted Answer

A) I only 
B) III only 
C) IV only 
D) I,II,IV 
E) I,II,III,IV 
A) I only 
B) III only 
C) IV only 
D) I,II,IV 
E) I,II,III,IV

Exam 13: Biochemical Signaling

Matching -The gland that is predominately responsible for producing the hormone that is released in response to consumption of a meal particularly high in carbohydrates.

Which of the following best describe the mechanism of calmodulin (CaM)mediated activation?

Anthrax toxin functions by altering levels of cAMP.The toxin also contains an edema factor,which requires the activity of calmodulin (CaM)for proper function.Based on this information,which of the following can you conclude?

Phospholipase C cleaves PIP2,resulting in an increased cytosolic concentration of (I)IP3 (inositolpolyphosphate-3) (II)protein kinase C (III)cAMP IV.Ca2+

Matching -Proteins that bind molecules and elicit a cellular response are called _____.

Autoinhibition in the SH2 and SH3 domains

Which of the following functions as a regulatory protein by dephosphorylating activated enzymes?

Matching -The first G protein-coupled receptor (GPCR)to be structurally analyzed at the atomic level was _____.

Somatostatin (I)inhibits the release of insulin. (II)inhibits the release of glucagon. (III)stimulates the release of insulin. (IV)stimulates the release of glucagon.

Matching -Isoproterenol functions as an agonist for receptors that bind hormones synthesized in the ___.

Matching -A release of _____ would result in the stimulation of the liver to synthesize glycogen.

Heterotrimeric G proteins (I)consist of three subunits,G α\alphaα ,G β\betaβ ,and G γ\gammaγ . (II)function as an autoinhibtory segment. (III)can function as a mediator to adenylate cyclase activity. (IV)are anchored to the cytoplasmic side of the membrane.

Matching -The ____ signaling pathway relies on GTP dependent hydrolysis for subsequent synthesis of cAMP.

Which of the following activities would lead to a decrease in the level of IP3 in the cytosol?

Insulin binds to a receptor that (I)is coupled to a G protein. (II)possesses tyrosine kinase activity. (III)possesses serine/threonine phosphatase activity. (IV)interact with proteins homologous to Src

Cancer causing viruses often contain: (I)oncogenes. (II)genes encoding variant proteins. (III)genes encoding cell proliferation inhibitors. (IV)genes capable of inducing malignant transformation.

Introduction to the Chemistry of Life

Water

Nucleotides, nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, inhibition and Control

Introduction to Metabolism

Glucose Catabolism

Glycogen Metabolism and Gluconeogenesis

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

Nucleic Acid Structure

DNA Replication, repair and Recombination

Transcription and Rna Processing

Protein Synthesis

Regulation of Gene Expression

Filters

Phospholipase C cleaves PIP₂,resulting in an increased cytosolic concentration of (I)IP₃ (inositolpolyphosphate-3) (II)protein kinase C (III)cAMP IV.Ca²⁺

Heterotrimeric G proteins (I)consist of three subunits,G $\alpha$ ,G $\beta$ ,and G $\gamma$ . (II)function as an autoinhibtory segment. (III)can function as a mediator to adenylate cyclase activity. (IV)are anchored to the cytoplasmic side of the membrane.

Which of the following activities would lead to a decrease in the level of IP₃ in the cytosol?