Question 1

Patients who have type 2 diabetes no longer respond normally to insulin.This symptom would be best explained by

Accepted Answer

A)  the signal transduction pathways in the cells no longer exist.
B)  Type 2 diabetics do not produce insulin.
C)  the insulin receptors on their cells have mutated.
D)  the nucleus of their cells are altered so that insulin can not binD.
E)  their cells express less insulin receptor.F) C) and D)
G) B) and C)

Question 2

Epinephrine blocks the contraction of muscles in the airways.Which of the other activities of epinephrine is most likely to be regulated by the same type of pathway?

Accepted Answer

A)  Contraction of smooth muscle cells in blood vessels
B)  Increased sweating
C)  Stimulation of heart muscle cell contraction
D)  Inhibition of saliva production in salivary glands
E)  Promotes the breakdown of glycogen in skeletal muscle cellsF) C) and E)
G) D) and E)

Question 3

After estrogen binds to receptors,these estrogen receptors gain activity of

Accepted Answer

A)  transcription factor.
B)  phosphatase.
C)  GTP binding.
D)  protein kinase.
E)  phospholipasE.F) B) and D)
G) A) and E)

Question 4

Following its initial activation,what becomes of a G protein?

Accepted Answer

A)  The G-protein a subunit containing a GTP eventually reassociates with the G-protein bg dimer.
B)  The G-protein a subunit GTP is hydrolyzed to GDP allowing reassociation of the G-protein a subunit and bg dimer.
C)  The G-protein a subunit is digested and recycled.
D)  It spontaneously loses activity within a few seconds.
E)  The receptor becomes internalized.F) C) and E)
G) B) and C)

Question 5

During exposure to elevated glucose,a yeast cell will increase its uptake of glucose.Describe the mechanism by which the yeast sense the extracellular glucose.

Accepted Answer

A)  By glucose diffusing into the nucleus and binding to transcription factors.
B)  By the increase in energy outside the cell when the glucose is metabolized.
C)  By glucose binding to glucose receptors.
D)  By the increase in energy inside the cell when the glucose is metabolizeD.
E)  By glucose uptake through glucose transporters.F) None of the above
G) A) and B)

Question 6

What happens immediately after a signaling molecule binds to its G-protein coupled receptor (GPCR) ?

Accepted Answer

A)  The signaling molecule enters the cell through its GPCR and travels to the nucleus,where it acts as a transcription factor.
B)  The G protein exchanges GTP for GDP,and becomes inactivated.
C)  The G protein exchanges GDP for GTP,and becomes inactivated.
D)  The G protein exchanges GTP for GDP,and becomes activateD.
E)  The G protein exchanges GDP for GTP,and becomes activated.F) A) and B)
G) A) and C)

Question 7

If the concentration of a ligand is 100 times greater than the Kd of its receptor,

Accepted Answer

A)  half of the receptors will be bound to a ligand.
B)  few of the receptors will be bound to a ligand.
C)  none of the receptors will be bound to a ligand.
D)  most of the receptors will be bound to a liganD.E) A) and C)
F) B) and C)

Question 8

Smooth muscle cells in the airways relax while those in the blood vessels contract in response to the hormone epinephrine.What would you expect to be different in these two types of cells exposed to epinephrine?

Accepted Answer

A)  Types of proteins expressed
B)  Exposure to epinephrine released by neighboring cells
C)  Activation of protein kinases
D)  Presence of epinephrine receptors
E)  Rate of metabolismF) C) and E)
G) B) and D)

Question 9

In terms of cell signaling,estrogen in animal cells works in a similar fashion as the plant hormone auxin via binding to intracellular receptors.

Accepted Answer

A) True 
 B)False

Question 10

Diabetics can be given insulin which binds to receptors on cells throughout the body increasing glucose uptake.Insulin is an example of a

Accepted Answer

A)  G-protein.
B)  signal.
C)  transcription factor.
D)  kinase.
E)  response element.F) A) and D)
G) A) and E)

Question 11

A cell responds to a signal it sent.This is an example of

Accepted Answer

A)  contact-dependent signaling.
B)  paracrine signaling.
C)  endocrine signaling.
D)  direct intercellular signaling.
E)  autocrine signaling.F) B) and D)
G) C) and E)

Question 12

The production of second messengers in signal transduction offers at least two advantages,speed and

Accepted Answer

A)  specificity.
B)  amplification.
C)  one-to-one stoichiometry.
D)  reversibility.
E)  affinity.F) A) and D)
G) None of the above

Question 13

A substrate binding to an enzyme is most similar to a signal molecule binding to a

Accepted Answer

A)  G-protein.
B)  receptor.
C)  kinase.
D)  second messenger.
E)  transcriptional factor.F) A) and D)
G) A) and E)

Question 14

Patients who have type 2 diabetes no longer express genes when exposed to insulin.How might this phenomenon be explained?

Accepted Answer

A)  The nucleus of their cells are altered so that insulin can not bind.
B)  The insulin signal transduction pathway becomes permanently activated.
C)  Transcription factors normally activated by insulin remain off.
D)  Insulin can no longer bind to the insulin receptor because the receptor is mutateD.
E)  The signal transduction pathways in the cells no longer exist.F) B) and D)
G) C) and D)

Question 15

G proteins and Ras are activated when bound to GDP.

Accepted Answer

A) True 
 B)False

Question 16

Estrogen is a lipid soluble hormone that can easily cross membranes.Knowing this,what can be concluded about estrogen receptors?

Accepted Answer

A)  The receptors would be linked to enzymes that triggered a kinase cascade.
B)  The receptors would be found inside the cell.
C)  The receptors would be coupled to a G-protein.
D)  The receptors would be on the plasma membrane.
E)  The receptors would also be lipid soluble and able to cross membranes.F) D) and E)
G) A) and B)

Question 17

The process through which cells can detect and respond to signals in their extracellular environment is

Accepted Answer

A)  sensory response.
B)  reception.
C)  cell communication.
D)  cell sensation.
E)  transduction.F) A) and B)
G) All of the above

Question 18

When epidermal growth factor binds to a(n) _______ receptor,the receptor phosphorylates itself,triggering a signal transduction pathway.

Accepted Answer

A)  G-protein coupled
B)  enzyme-linked
C)  mechano
D)  ligand-gated ion channel
E)  thermoF) D) and E)
G) B) and E)

Question 19

Sodium ions move from one cardiac muscle cell to an adjacent cell causing them to contract in unison.This is an example of

Accepted Answer

A)  contact-dependent signaling.
B)  paracrine signaling.
C)  endocrine signaling.
D)  autocrine signaling.
E)  direct intercellular signaling.F) A) and C)
G) None of the above

Exam 8: Cell Communication

Smooth muscle cells in the airways relax while those in the blood vessels contract in response to the hormone epinephrine.What would you expect to be different in these two types of cells exposed to epinephrine?

Correct Answer
verified

Estrogen is a lipid soluble hormone that can easily cross membranes.Knowing this,what can be concluded about estrogen receptors?

Correct Answer
verified

Patients who have type 2 diabetes no longer respond normally to insulin.This symptom would be best explained by

Correct Answer
verified

A substrate binding to an enzyme is most similar to a signal molecule binding to a

Correct Answer
verified

Diabetics can be given insulin which binds to receptors on cells throughout the body increasing glucose uptake.Insulin is an example of a

Correct Answer
verified

Epinephrine blocks the contraction of muscles in the airways.Which of the other activities of epinephrine is most likely to be regulated by the same type of pathway?

Correct Answer
verified

A cell responds to a signal it sent.This is an example of

Correct Answer
verified

What happens immediately after a signaling molecule binds to its G-protein coupled receptor (GPCR) ?

Correct Answer
verified

Sodium ions move from one cardiac muscle cell to an adjacent cell causing them to contract in unison.This is an example of

Correct Answer
verified

In terms of cell signaling,estrogen in animal cells works in a similar fashion as the plant hormone auxin via binding to intracellular receptors.

Correct Answer
verified

When epidermal growth factor binds to a(n) _______ receptor,the receptor phosphorylates itself,triggering a signal transduction pathway.

Correct Answer
verified

After estrogen binds to receptors,these estrogen receptors gain activity of

Correct Answer
verified

Following its initial activation,what becomes of a G protein?

Correct Answer
verified

G proteins and Ras are activated when bound to GDP.

Correct Answer
verified

During exposure to elevated glucose,a yeast cell will increase its uptake of glucose.Describe the mechanism by which the yeast sense the extracellular glucose.

Correct Answer
verified

Patients who have type 2 diabetes no longer express genes when exposed to insulin.How might this phenomenon be explained?

Correct Answer
verified

If the concentration of a ligand is 100 times greater than the Kd of its receptor,

Correct Answer
verified

The process through which cells can detect and respond to signals in their extracellular environment is

Correct Answer
verified

The production of second messengers in signal transduction offers at least two advantages,speed and

Correct Answer
verified

Exam 8: Cell Communication

Smooth muscle cells in the airways relax while those in the blood vessels contract in response to the hormone epinephrine.What would you expect to be different in these two types of cells exposed to epinephrine?

Correct AnswerverifiedShow Answer

Estrogen is a lipid soluble hormone that can easily cross membranes.Knowing this,what can be concluded about estrogen receptors?

Correct AnswerverifiedShow Answer

Patients who have type 2 diabetes no longer respond normally to insulin.This symptom would be best explained by

Correct AnswerverifiedShow Answer

A substrate binding to an enzyme is most similar to a signal molecule binding to a

Correct AnswerverifiedShow Answer

Diabetics can be given insulin which binds to receptors on cells throughout the body increasing glucose uptake.Insulin is an example of a

Correct AnswerverifiedShow Answer

Epinephrine blocks the contraction of muscles in the airways.Which of the other activities of epinephrine is most likely to be regulated by the same type of pathway?

Correct AnswerverifiedShow Answer

A cell responds to a signal it sent.This is an example of

Correct AnswerverifiedShow Answer

What happens immediately after a signaling molecule binds to its G-protein coupled receptor (GPCR) ?

Correct AnswerverifiedShow Answer

Sodium ions move from one cardiac muscle cell to an adjacent cell causing them to contract in unison.This is an example of

Correct AnswerverifiedShow Answer

In terms of cell signaling,estrogen in animal cells works in a similar fashion as the plant hormone auxin via binding to intracellular receptors.

Correct AnswerverifiedShow Answer

When epidermal growth factor binds to a(n) _______ receptor,the receptor phosphorylates itself,triggering a signal transduction pathway.

Correct AnswerverifiedShow Answer

After estrogen binds to receptors,these estrogen receptors gain activity of

Correct AnswerverifiedShow Answer

Following its initial activation,what becomes of a G protein?

Correct AnswerverifiedShow Answer

G proteins and Ras are activated when bound to GDP.

Correct AnswerverifiedShow Answer

During exposure to elevated glucose,a yeast cell will increase its uptake of glucose.Describe the mechanism by which the yeast sense the extracellular glucose.

Correct AnswerverifiedShow Answer

Patients who have type 2 diabetes no longer express genes when exposed to insulin.How might this phenomenon be explained?

Correct AnswerverifiedShow Answer

If the concentration of a ligand is 100 times greater than the Kd of its receptor,

Correct AnswerverifiedShow Answer

The process through which cells can detect and respond to signals in their extracellular environment is

Correct AnswerverifiedShow Answer

The production of second messengers in signal transduction offers at least two advantages,speed and

Correct AnswerverifiedShow Answer

Correct Answer
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