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CHEM 210 Biochemistry Module 8
Exam (2024/2025) – Portage Learning
Questions and Verified Answers |
100% Guarantee Pass
Hormonal Regulation
1. Which hormone primarily stimulates glycogenolysis in the liver?
a) Insulin
b) Glucagon
c) Cortisol
d) Epinephrine
Answer: b) Glucagon
Rationale: Glucagon, released by pancreatic alpha cells, stimulates glycogenolysis in the
liver to increase blood glucose levels by activating glycogen phosphorylase, per Portage
Learning standards.
2. What is the primary effect of insulin on glucose metabolism?
a) Stimulates gluconeogenesis
b) Promotes glucose uptake in cells
c) Inhibits glycolysis
d) Increases glycogen breakdown
Answer: b) Promotes glucose uptake in cells
Rationale: Insulin facilitates glucose uptake by promoting GLUT4 transporter
translocation to cell membranes, particularly in muscle and adipose tissue, enhancing
glycolysis and glycogen synthesis.
3. Which hormone increases lipolysis in adipose tissue during fasting?
a) Insulin
b) Glucagon
c) Leptin
d) Ghrelin
Answer: b) Glucagon
Rationale: Glucagon activates hormone-sensitive lipase in adipose tissue, promoting
lipolysis to release fatty acids for energy during fasting, per Portage Learning standards.
4. How does cortisol influence protein metabolism?
a) Stimulates protein synthesis
b) Inhibits protein catabolism
c) Promotes protein breakdown
d) Has no effect on protein metabolism
Answer: c) Promotes protein breakdown
, 2
Rationale: Cortisol, a glucocorticoid, promotes protein catabolism in muscle to provide
amino acids for gluconeogenesis during stress, per biochemical principles.
5. Which hormone inhibits glucose uptake in peripheral tissues during stress?
a) Insulin
b) Epinephrine
c) Thyroxine
d) Glucagon
Answer: b) Epinephrine
Rationale: Epinephrine, released during stress, inhibits insulin-mediated glucose uptake
and promotes glycogenolysis and gluconeogenesis to prioritize glucose availability for
vital organs.
Signal Transduction
6. What is the role of cyclic AMP (cAMP) in signal transduction?
a) Inhibits enzyme activity
b) Acts as a second messenger
c) Directly binds to DNA
d) Transports ions across membranes
Answer: b) Acts as a second messenger
Rationale: cAMP is a second messenger that amplifies hormonal signals by activating
protein kinase A, which phosphorylates target proteins to elicit cellular responses, per
Portage Learning standards.
7. Which enzyme converts ATP to cAMP in response to hormonal signaling?
a) Phosphodiesterase
b) Adenylyl cyclase
c) Protein kinase A
d) Phospholipase C
Answer: b) Adenylyl cyclase
Rationale: Adenylyl cyclase is activated by G-protein-coupled receptors to convert ATP
to cAMP, initiating signal transduction cascades, per biochemical principles.
8. What is the primary function of G-protein-coupled receptors (GPCRs)?
a) Synthesize hormones
b) Bind extracellular ligands to initiate signaling
c) Transport glucose into cells
d) Degrade second messengers
Answer: b) Bind extracellular ligands to initiate signaling
Rationale: GPCRs bind hormones or ligands, activating G-proteins to trigger
intracellular signaling pathways like cAMP or IP3 cascades, per Portage Learning
standards.
9. Which molecule is produced in the IP3-DAG pathway?
a) Cyclic GMP
b) Inositol triphosphate
c) Cyclic AMP
CHEM 210 Biochemistry Module 8
Exam (2024/2025) – Portage Learning
Questions and Verified Answers |
100% Guarantee Pass
Hormonal Regulation
1. Which hormone primarily stimulates glycogenolysis in the liver?
a) Insulin
b) Glucagon
c) Cortisol
d) Epinephrine
Answer: b) Glucagon
Rationale: Glucagon, released by pancreatic alpha cells, stimulates glycogenolysis in the
liver to increase blood glucose levels by activating glycogen phosphorylase, per Portage
Learning standards.
2. What is the primary effect of insulin on glucose metabolism?
a) Stimulates gluconeogenesis
b) Promotes glucose uptake in cells
c) Inhibits glycolysis
d) Increases glycogen breakdown
Answer: b) Promotes glucose uptake in cells
Rationale: Insulin facilitates glucose uptake by promoting GLUT4 transporter
translocation to cell membranes, particularly in muscle and adipose tissue, enhancing
glycolysis and glycogen synthesis.
3. Which hormone increases lipolysis in adipose tissue during fasting?
a) Insulin
b) Glucagon
c) Leptin
d) Ghrelin
Answer: b) Glucagon
Rationale: Glucagon activates hormone-sensitive lipase in adipose tissue, promoting
lipolysis to release fatty acids for energy during fasting, per Portage Learning standards.
4. How does cortisol influence protein metabolism?
a) Stimulates protein synthesis
b) Inhibits protein catabolism
c) Promotes protein breakdown
d) Has no effect on protein metabolism
Answer: c) Promotes protein breakdown
, 2
Rationale: Cortisol, a glucocorticoid, promotes protein catabolism in muscle to provide
amino acids for gluconeogenesis during stress, per biochemical principles.
5. Which hormone inhibits glucose uptake in peripheral tissues during stress?
a) Insulin
b) Epinephrine
c) Thyroxine
d) Glucagon
Answer: b) Epinephrine
Rationale: Epinephrine, released during stress, inhibits insulin-mediated glucose uptake
and promotes glycogenolysis and gluconeogenesis to prioritize glucose availability for
vital organs.
Signal Transduction
6. What is the role of cyclic AMP (cAMP) in signal transduction?
a) Inhibits enzyme activity
b) Acts as a second messenger
c) Directly binds to DNA
d) Transports ions across membranes
Answer: b) Acts as a second messenger
Rationale: cAMP is a second messenger that amplifies hormonal signals by activating
protein kinase A, which phosphorylates target proteins to elicit cellular responses, per
Portage Learning standards.
7. Which enzyme converts ATP to cAMP in response to hormonal signaling?
a) Phosphodiesterase
b) Adenylyl cyclase
c) Protein kinase A
d) Phospholipase C
Answer: b) Adenylyl cyclase
Rationale: Adenylyl cyclase is activated by G-protein-coupled receptors to convert ATP
to cAMP, initiating signal transduction cascades, per biochemical principles.
8. What is the primary function of G-protein-coupled receptors (GPCRs)?
a) Synthesize hormones
b) Bind extracellular ligands to initiate signaling
c) Transport glucose into cells
d) Degrade second messengers
Answer: b) Bind extracellular ligands to initiate signaling
Rationale: GPCRs bind hormones or ligands, activating G-proteins to trigger
intracellular signaling pathways like cAMP or IP3 cascades, per Portage Learning
standards.
9. Which molecule is produced in the IP3-DAG pathway?
a) Cyclic GMP
b) Inositol triphosphate
c) Cyclic AMP
