BIOL 2P03 Student Name: ______________________
Midterm 3Student Number: ___________________
Section 1: Multiple Choice. Answer all questions on the Scantron provided. There are 20
questions. Each question is worth 1 mark for a total of 20 marks.
1. __________ signaling pathways use hormones as their signaling molecules.
a) Autocrine
b) Endocrine
c) Exocrine
d) Paracrine
e) Plasma membrane-attached protein
2. Which of the following is not a common mechanism used by receptors to initiate an
intracellular transduction pathway?
a) Activating an enzyme that is intrinsic to a receptor
b) Activating a heterotrimeric G-protein
c) Opening a pore in a receptor for ions to flow through
d) Activating an enzyme attached to a receptor
e) All of the above can be used to initiate intracellular transduction pathways
3. Competitive antagonists
a) Irreversibly bind to the ligand binding site on a receptor
b) Bind to an allosteric site on a receptor to alter the affinity of the receptor for its ligand
c) Competes with the agonist for the ligand binding site on a receptor
d) Shift the dose response curve for an agonist to the left
e) Both a) and b) are correct
4. All of the following molecules are classified as second messengers except
a) Ca2+ (Calcium)
b) cAMP (Cyclic adenosine monophosphate)
c) IP3 (Inositol 1,4,5-trisphosphate)
d) Protein kinase A
e) All of the above are second messengers
5. Activated phospholipase C produces
a) PIP2 (Phosphatidylinositol 4,5-bisphosphate)
b) IP3 (Inositol 1,4,5-trisphosphate)
c) DAG (Diacylglycerol)
d) Both b) and c) are correct
6. cAMP is
a) Produced by adenylyl cyclase and degraded by phosphodiesterases
b) Produced by phosphodiesterases and degraded by adenylyl cyclase
c) Produced by adenylyl cyclase and degraded by protein kinases
d) Produced by protein kinases and degraded by adenylyl cyclase
e) None of the above
, BIOL 2P03 Student Name: ______________________
Midterm 3Student Number: ___________________
7. Ca2+ release from the endoplasmic reticulum is stimulated by
a) cAMP
b) Calmodulin
c) IP3
d) DAG
e) PIP2
8. G-protein coupled receptors
a) Are activated by receptor dimerization
b) Are the least diverse class of plasma membrane receptors
c) Activate heterotrimeric G-proteins by facilitating the exchange of GDP for GTP
d) Possess intrinsic kinase activities
e) Can be cleaved to generate transcription factors
9. Heterotrimeric G-proteins
a) Are always bound to G-protein coupled receptors
b) Consist of α, β and γ subunits
c) Can directly interact with cytosolic enzymes to activate them
d) Are activated by phosphorylation via protein kinases
e) All of the above
10. Which of the following heterotrimeric G-proteins affect(s) cAMP production?
a) Gαs
b) Gαi
c) Gαq
d) All of the above affect cAMP production
e) Only a) and b) are correct
11. In a resting cell, Nuclear Factor-κB (NF- κB) is located in the
a) Mitochondria
b) Nucleus
c) Plasma membrane
d) Cytosol
e) None of the above
12. cAMP response element binding protein (CREB) is a/an
a) Protein kinase
b) Protein phosphatase
c) Transcription factor
d) Small G-protein
e) Inhibitor of a transcription factor
Midterm 3Student Number: ___________________
Section 1: Multiple Choice. Answer all questions on the Scantron provided. There are 20
questions. Each question is worth 1 mark for a total of 20 marks.
1. __________ signaling pathways use hormones as their signaling molecules.
a) Autocrine
b) Endocrine
c) Exocrine
d) Paracrine
e) Plasma membrane-attached protein
2. Which of the following is not a common mechanism used by receptors to initiate an
intracellular transduction pathway?
a) Activating an enzyme that is intrinsic to a receptor
b) Activating a heterotrimeric G-protein
c) Opening a pore in a receptor for ions to flow through
d) Activating an enzyme attached to a receptor
e) All of the above can be used to initiate intracellular transduction pathways
3. Competitive antagonists
a) Irreversibly bind to the ligand binding site on a receptor
b) Bind to an allosteric site on a receptor to alter the affinity of the receptor for its ligand
c) Competes with the agonist for the ligand binding site on a receptor
d) Shift the dose response curve for an agonist to the left
e) Both a) and b) are correct
4. All of the following molecules are classified as second messengers except
a) Ca2+ (Calcium)
b) cAMP (Cyclic adenosine monophosphate)
c) IP3 (Inositol 1,4,5-trisphosphate)
d) Protein kinase A
e) All of the above are second messengers
5. Activated phospholipase C produces
a) PIP2 (Phosphatidylinositol 4,5-bisphosphate)
b) IP3 (Inositol 1,4,5-trisphosphate)
c) DAG (Diacylglycerol)
d) Both b) and c) are correct
6. cAMP is
a) Produced by adenylyl cyclase and degraded by phosphodiesterases
b) Produced by phosphodiesterases and degraded by adenylyl cyclase
c) Produced by adenylyl cyclase and degraded by protein kinases
d) Produced by protein kinases and degraded by adenylyl cyclase
e) None of the above
, BIOL 2P03 Student Name: ______________________
Midterm 3Student Number: ___________________
7. Ca2+ release from the endoplasmic reticulum is stimulated by
a) cAMP
b) Calmodulin
c) IP3
d) DAG
e) PIP2
8. G-protein coupled receptors
a) Are activated by receptor dimerization
b) Are the least diverse class of plasma membrane receptors
c) Activate heterotrimeric G-proteins by facilitating the exchange of GDP for GTP
d) Possess intrinsic kinase activities
e) Can be cleaved to generate transcription factors
9. Heterotrimeric G-proteins
a) Are always bound to G-protein coupled receptors
b) Consist of α, β and γ subunits
c) Can directly interact with cytosolic enzymes to activate them
d) Are activated by phosphorylation via protein kinases
e) All of the above
10. Which of the following heterotrimeric G-proteins affect(s) cAMP production?
a) Gαs
b) Gαi
c) Gαq
d) All of the above affect cAMP production
e) Only a) and b) are correct
11. In a resting cell, Nuclear Factor-κB (NF- κB) is located in the
a) Mitochondria
b) Nucleus
c) Plasma membrane
d) Cytosol
e) None of the above
12. cAMP response element binding protein (CREB) is a/an
a) Protein kinase
b) Protein phosphatase
c) Transcription factor
d) Small G-protein
e) Inhibitor of a transcription factor
