Question 1

Which represents the correct ordering from lowest number to highest number of molecules in a liver cell activated by a single molecule of epinephrine?

Accepted Answer

A)  cAMP, protein kinase A, phosphorylase kinase, glycogen phosphorylase 
B)  Glycogen phosphorylase, phosphorylase kinase, protein kinase A, cAMP 
C)  cAMP, phosphorylase kinase, glycogen phosphorylase, protein kinase A 
D)  Glycogen phosphorylase, cAMP, protein kinase A, phosphorylase kinase 
E)  Phosphorylase kinase, glycogen phosphorylase, cAMP, protein kinase A 
A)  cAMP, protein kinase A, phosphorylase kinase, glycogen phosphorylase 
B)  Glycogen phosphorylase, phosphorylase kinase, protein kinase A, cAMP 
C)  cAMP, phosphorylase kinase, glycogen phosphorylase, protein kinase A 
D)  Glycogen phosphorylase, cAMP, protein kinase A, phosphorylase kinase 
E)  Phosphorylase kinase, glycogen phosphorylase, cAMP, protein kinase A

Question 2

Which is an example that explains how a juxtacrine signal functions in the human body?

Accepted Answer

A)  At the junction of two nerve cells, one of the cells secretes a neurotransmitter molecule that diffuses over to the neighboring cell, where it binds and stimulates an electrochemical response. 
B)  To signal hunger, cells in the stomach secrete a peptide that circulates through the blood and binds to receptors on cells in the hypothalamus in the brain. 
C)  When the skin is injured, chemical signals are sent from nearby blood cells to aid in healing. 
D)  T lymphocytes secrete a chemical signal that stimulates those same T lymphocytes to undergo cell division. 
E)  A cell in a developing embryo has a cell surface protein that directly contacts a receptor on a neighboring cell, causing it to change its gene expression pattern. 
A)  At the junction of two nerve cells, one of the cells secretes a neurotransmitter molecule that diffuses over to the neighboring cell, where it binds and stimulates an electrochemical response. 
B)  To signal hunger, cells in the stomach secrete a peptide that circulates through the blood and binds to receptors on cells in the hypothalamus in the brain. 
C)  When the skin is injured, chemical signals are sent from nearby blood cells to aid in healing. 
D)  T lymphocytes secrete a chemical signal that stimulates those same T lymphocytes to undergo cell division. 
E)  A cell in a developing embryo has a cell surface protein that directly contacts a receptor on a neighboring cell, causing it to change its gene expression pattern.

Question 3

An event in a signal transduction pathway that has a direct effect on gene expression is activation of

Accepted Answer

A)  an enzyme by the addition of a phosphate group. 
B)  a translation factor in the cytoplasm. 
C)  an enzyme in the cytoplasm. 
D)  a transcription factor and its relocation to the nucleus. 
E)  a ribosome to initiate protein synthesis. 
A)  an enzyme by the addition of a phosphate group. 
B)  a translation factor in the cytoplasm. 
C)  an enzyme in the cytoplasm. 
D)  a transcription factor and its relocation to the nucleus. 
E)  a ribosome to initiate protein synthesis.

Question 4

A deleterious mutation in the gene for phospholipase C destroyed its biological function.How would that affect the body's response to oxytocin?

Accepted Answer

A)  The response to oxytocin would slow down. 
B)  The response to oxytocin would speed up. 
C)  The response to oxytocin would change and a different type of cellular response would be activated. 
D)  There would be no response to oxytocin, because the signal transduction pathway would be nonfunctional. 
E)  There would be no response to oxytocin, because the signal transduction pathway would be constantly activated. 
A)  The response to oxytocin would slow down. 
B)  The response to oxytocin would speed up. 
C)  The response to oxytocin would change and a different type of cellular response would be activated. 
D)  There would be no response to oxytocin, because the signal transduction pathway would be nonfunctional. 
E)  There would be no response to oxytocin, because the signal transduction pathway would be constantly activated.

Question 5

Cyclic AMP is a second messenger in many different responses.How can the same messenger act in different ways in different cells?

Accepted Answer

Different cells can have different targe

Question 6

Three second messengers involved in penile erections are

Accepted Answer

A)  nitric oxide, inositol trisphosphate, and calcium ions. 
B)  adenylcyclase, phospholipase C, and calcium ions. 
C)  cyclic AMP, nitric oxide, and cyclic GMP. 
D)  adenylyl cyclase, calcium ions, and nitric oxide. 
E)  cyclic GMP, acetylcholine, and inositol trisphosphate. 
A)  nitric oxide, inositol trisphosphate, and calcium ions. 
B)  adenylcyclase, phospholipase C, and calcium ions. 
C)  cyclic AMP, nitric oxide, and cyclic GMP. 
D)  adenylyl cyclase, calcium ions, and nitric oxide. 
E)  cyclic GMP, acetylcholine, and inositol trisphosphate.

Exam 7: Cell Communication and Multicellularity

Which represents the correct ordering from lowest number to highest number of molecules in a liver cell activated by a single molecule of epinephrine?

Which is an example that explains how a juxtacrine signal functions in the human body?

An event in a signal transduction pathway that has a direct effect on gene expression is activation of

A deleterious mutation in the gene for phospholipase C destroyed its biological function.How would that affect the body's response to oxytocin?

Cyclic AMP is a second messenger in many different responses.How can the same messenger act in different ways in different cells?

Three second messengers involved in penile erections are

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