Question 1

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 onlyF) B) and D)
G) None of the above

Question 2

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 proteinF) A) and C)
G) B) and E)

Question 3

Matching
-The ____ signaling pathway undergoes autophosphorylation resulting in kinase activation.

Accepted Answer

A)  receptors
B)  phosphoinositide
C)  rhodopsin
D)  calmodulin
E)  insulinF) hypothalamusG) cortisolH) adrenal cortexI) cyclic AMPJ) RasGAPK) islets of LangerhansL) adenylate cyclase (A
C)  M) receptor tyrosine kinase (RTK) N) C) and L)
O) D) and F)

Question 4

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 aboveF) A) and D)
G) C) and E)

Question 5

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)  insulinF) hypothalamusG) cortisolH) adrenal cortexI) cyclic AMPJ) RasGAPK) islets of LangerhansL) adenylate cyclase (A
C)  M) receptor tyrosine kinase (RTK) N) A) and J)
O) J) and K)

Question 6

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, IVF) B) and D)
G) B) and C)

Question 7

Which of the following are produced in the adrenal cortex?
I.Glucorticoids
II.mineralcorticoides
III.androgens
IV.estrogens

Accepted Answer

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

Question 8

The activity of protein kinase A is affected by which of the following?
I.caffeine
II.levels of cAMP
III.phosphodiesterases
IV.cholera toxin

Accepted Answer

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

Question 9

Which of the following hormones functions by binding to receptors that function directly as transcription factors?

Accepted Answer

A)  steroids
B)  insulin
C)  epinephrine
D)  glucagon
E)  somatostatinF) All of the above
G) B) and D)

Question 10

Oncogenes
I.function as cell cycle inhibitors.
II.encode a protein which block cell cycle inhibition.
III.are expressed by cells that have higher levels of human growth hormone.
IV.can function as transcription factors.

Accepted Answer

A)  I, III, IV
B)  II, III
C)  III, IV
D)  II, IV
E)  IIF) All of the above
G) D) and E) D

Question 11

Which of the following sets of terms has a member that does not belong?

Accepted Answer

A)  rhodopsin - heterotrimeric G protein - desensitization
B)  autoinhibitor segment - receptor tyrosine kinase - SH2
C)  propranolol - β-adrenoreceptor - antagonist
D)  transcortin - aldosterone - adrenal cortex
E)  adenylate cyclase - cholera toxin - heterotrimeric G proteinF) C) and D)
G) A) and D)

Question 12

Which of the following increases the affinity of SH2 binding to phosphor-tyrosine?

Accepted Answer

A)  The absence of a Ser or Thr residue in the binding region.
B)  The presence of an Arg residue deep in the binding pocket.
C)  The presence of an Arg residue near the binding pocket entrance.
D)  The absence of a Ser residue deep in the binding pocket.
E)  None of the above.F) C) and D)
G) B) and C)

Question 13

Which of the following generalizations explains how anabolic steroids can affect muscle growth?

Accepted Answer

A)  Anabolic steroids increase the level of testosterone, a hormone predominately found in males.
B)  Anabolic steroids easily pass through the membrane and bind steroid receptors which migrate to the nucleus and function as a transcription factor.
C)  Anabolic steroids are water soluble and can transport to the muscle tissue readily.
D)  Anabolic steroids alter the phosphoinositide pathway, thereby increasing levels of calcium in the cytosol and subsequently increase the strength of muscle contraction.
E)  None of the above is correct.F) C) and E)
G) A) and B)

Question 14

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.F) A) and C)
G) C) and D)

Question 15

The interaction (cross-talk) of various signaling pathways

Accepted Answer

A)  allows for dual-specificity within different cell types.
B)  is necessary for effective signal transduction.
C)  occurs during autoinhibition of a pathway.
D)  accounts for the ability of a signaling pathway to undergo desensitization.
E)  can be minimized by scaffold proteins.F) B) and E)
G) D) and E) E

Question 16

Sildenafil (Viagra)

Accepted Answer

A)  inhibits activity of a phosphoprotein phosphatase.
B)  increases the relative concentration of cGMP.
C)  increases the relative concentration of nitric oxide in the blood.
D)  A, B, and C
E)  A and BF) A) and C)
G) A) and B)

Question 17

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 onlyF) B) and E)
G) A) and E)

Question 18

The virulent form of bubonic plague carries a protein called YopH.Which of the following is true?

Accepted Answer

A)  YopH functions as a MAPK specific inhibitor.
B)  YopH functions as a Ras inhibitor.
C)  YopH functions as a receptor tyrosine kinase.
D)  YopH functions as a protein tyrosine phosphatase.
E)  YopH functions as β propeller.F) A) and B)
G) None of the above D

Question 19

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 CF) B) and D)
G) None of the above

Question 20

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 onlyF) All of the above
G) None of the above

Exam 13: Biochemical Signaling

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

Correct Answer
verified

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

Correct Answer
verified

Matching -The ____ signaling pathway undergoes autophosphorylation resulting in kinase activation.

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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.

Correct Answer
verified

Which of the following are produced in the adrenal cortex? I.Glucorticoids II.mineralcorticoides III.androgens IV.estrogens

Correct Answer
verified

The activity of protein kinase A is affected by which of the following? I.caffeine II.levels of cAMP III.phosphodiesterases IV.cholera toxin

Correct Answer
verified

Which of the following hormones functions by binding to receptors that function directly as transcription factors?

Correct Answer
verified

Oncogenes I.function as cell cycle inhibitors. II.encode a protein which block cell cycle inhibition. III.are expressed by cells that have higher levels of human growth hormone. IV.can function as transcription factors.

Correct Answer
verified
D

Which of the following sets of terms has a member that does not belong?

Correct Answer
verified

Which of the following increases the affinity of SH2 binding to phosphor-tyrosine?

Correct Answer
verified

Which of the following generalizations explains how anabolic steroids can affect muscle growth?

Correct Answer
verified

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

Correct Answer
verified

The interaction (cross-talk) of various signaling pathways

Correct Answer
verified
E

Sildenafil (Viagra)

Correct Answer
verified

Correct Answer
verified

The virulent form of bubonic plague carries a protein called YopH.Which of the following is true?

Correct Answer
verified
D

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?

Correct Answer
verified

Correct Answer
verified

Exam 13: Biochemical Signaling

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Matching -The ____ signaling pathway undergoes autophosphorylation resulting in kinase activation.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedShow Answer

Which of the following are produced in the adrenal cortex? I.Glucorticoids II.mineralcorticoides III.androgens IV.estrogens

Correct AnswerverifiedShow Answer

The activity of protein kinase A is affected by which of the following? I.caffeine II.levels of cAMP III.phosphodiesterases IV.cholera toxin

Correct AnswerverifiedShow Answer

Which of the following hormones functions by binding to receptors that function directly as transcription factors?

Correct AnswerverifiedShow Answer

Oncogenes I.function as cell cycle inhibitors. II.encode a protein which block cell cycle inhibition. III.are expressed by cells that have higher levels of human growth hormone. IV.can function as transcription factors.

Correct AnswerverifiedD

Which of the following sets of terms has a member that does not belong?

Correct AnswerverifiedShow Answer

Which of the following increases the affinity of SH2 binding to phosphor-tyrosine?

Correct AnswerverifiedShow Answer

Which of the following generalizations explains how anabolic steroids can affect muscle growth?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The interaction (cross-talk) of various signaling pathways

Correct AnswerverifiedE

Sildenafil (Viagra)

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The virulent form of bubonic plague carries a protein called YopH.Which of the following is true?

Correct AnswerverifiedD

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?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
E

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified

Correct Answer
verified