Question 1

Synthetic compounds that inhibit receptors by preventing the natural messenger from binding are known as

Accepted Answer

A) agonists. 
B) receptor upregulators. 
C) specific proteoglycans. 
D) syndecans. 
E) antagonists. 
A) agonists. 
B) receptor upregulators. 
C) specific proteoglycans. 
D) syndecans. 
E) antagonists. E

Question 2

In situations where signaling pathway components need to be "fixed" in a particular position within the cell (e.g.,in the yeast mating pathway),they are associated with ________.

Accepted Answer

scaffolding proteins.

Question 3

The α-subunit of a heterotrimeric G protein is active when bound to ________.

Accepted Answer

GTP

Question 4

________ are genetically engineered proteins that allow cytosolic calcium fluxes to be observed by an increase in fluorescence.

Accepted Answer

The answer of ________ are genetically engineered proteins that allow...

Question 5

Compare and contrast cell signalling via receptor serine/threonine kinases and Ras.

Accepted Answer

Receptor serine/threonine kinases act th

Question 6

Which of the following signalling proteins is specifically associated with development in animals?

Accepted Answer

A) Hedgehog 
B) Zbtb7 
C) Ryanodine 
D) calcium-dependent protein phosphorylases 
E) protein kinase A 
A) Hedgehog 
B) Zbtb7 
C) Ryanodine 
D) calcium-dependent protein phosphorylases 
E) protein kinase A

Question 7

When nitric oxide is used in the dilation of smooth muscle cells,which of the following would interfere with the relaxation of the smooth muscle cells? Inhibitors of

Accepted Answer

A) calcium release by the ER. 
B) nitric oxide. 
C) guanylyl cyclase. 
D) calmodulin. 
E) all of the above 
A) calcium release by the ER. 
B) nitric oxide. 
C) guanylyl cyclase. 
D) calmodulin. 
E) all of the above

Question 8

Which of the following statements concerning the properties of ligands for intracellular receptor systems is correct?

Accepted Answer

A) Steroids are produced from cholesterol. 
B) Changes in the composition of your diet can affect the concentration of some of these ligands in your body. 
C) Some ligands are bound to specific proteins when carried in the blood. 
D) both choices A and C 
E) choices A, B, and C 
A) Steroids are produced from cholesterol. 
B) Changes in the composition of your diet can affect the concentration of some of these ligands in your body. 
C) Some ligands are bound to specific proteins when carried in the blood. 
D) both choices A and C 
E) choices A, B, and C

Question 9

The kinase central to second messenger signalling based cAMP is

Accepted Answer

A) protein kinase A. 
B) ATPase. 
C) Avastin kinase. 
D) phosphorylase A. 
E) RNase PH. 
A) protein kinase A. 
B) ATPase. 
C) Avastin kinase. 
D) phosphorylase A. 
E) RNase PH.

Question 10

You obtain two different preparations of XFF,one of which contains the receptors for XFF.You perform a binding assay and obtain a standard curve.Based upon this data,what value would reflect the affinity of the receptor for the ligand? (Assume a 1 XFF-to-1 receptor interaction.)

Accepted Answer

A) Kd 
B) Bmax 
C) Kd - Bmax 
D) 1/Bmax 
E) The affinity cannot be detertmined from the information available 
A) Kd 
B) Bmax 
C) Kd - Bmax 
D) 1/Bmax 
E) The affinity cannot be detertmined from the information available

Question 11

Which of the following pairings is not correct?

Accepted Answer

A) adenylyl cyclase-ATP 
B) phospholipase C-diacylglycerol (DAG) 
C) phospholipase C-inositol triphosphate 
D) calmodulin-calcium ions 
A) adenylyl cyclase-ATP 
B) phospholipase C-diacylglycerol (DAG) 
C) phospholipase C-inositol triphosphate 
D) calmodulin-calcium ions

Question 12

In designing a new drug that may interfere with G-protein coupled receptor interacting protein functions,one possible target for drug action is not

Accepted Answer

A) altering ligand affinity for the receptor. 
B) promoting close association with other signal proteins. 
C) modifying epinephrine production. 
D) promoting receptor dimerization. 
E) controlling receptor localization in the membrane. 
A) altering ligand affinity for the receptor. 
B) promoting close association with other signal proteins. 
C) modifying epinephrine production. 
D) promoting receptor dimerization. 
E) controlling receptor localization in the membrane.

Question 13

Which of the following would be characterized as a juxtacrine signal?

Accepted Answer

A) contact-dependent 
B) endocrine 
C) self-responding 
D) distal neighbors 
E) both choices B and D 
A) contact-dependent 
B) endocrine 
C) self-responding 
D) distal neighbors 
E) both choices B and D

Question 14

In heterotrimeric G proteins,the ________ subunit stimulates adenylyl kinase.

Accepted Answer

The answer of In heterotrimeric G proteins,the ________ subunit stimulates...

Question 15

________ is the second messenger associated with the regulation of blood pressure.

Accepted Answer

The answer of ________ is the second messenger associated with...

Question 16

A type of programmed cell death associated with DNA fragmentation and caspases is known as ________.

Accepted Answer

The answer of A type of programmed cell death associated...

Question 17

Which of the following statements regarding the Ras protein is false?

Accepted Answer

A) Ras is monomeric. 
B) It is regulated by GTPase activating proteins. 
C) The ligands are largely steroid hormones. 
D) It is regulated by Sos, a guanine nucleotide exchange factor. 
E) Ras activates a cascade of phosphorylation events. 
A) Ras is monomeric. 
B) It is regulated by GTPase activating proteins. 
C) The ligands are largely steroid hormones. 
D) It is regulated by Sos, a guanine nucleotide exchange factor. 
E) Ras activates a cascade of phosphorylation events.

Question 18

Prostaglandins are not

Accepted Answer

A) endocrine hormones. 
B) important in smooth muscle function. 
C) paracrine hormones. 
D) stimulators of inflammation. 
E) formed from arachidonic acid. 
A) endocrine hormones. 
B) important in smooth muscle function. 
C) paracrine hormones. 
D) stimulators of inflammation. 
E) formed from arachidonic acid.

Question 19

G protein-adenyl cyclase activity has been shown,in some cases,to be associated with certain diseases.In the case of cholera,which of the following is not correct?

Accepted Answer

A) Vibrio cholera bacteria colonize the gut. 
B) Cholera toxin is secreted by Vibrio cholera bacteria. 
C) The cholera toxin causes the cells of the gut to take in salts and fluids. 
D) Cholera toxin alters Gs so that it no longer hydrolyzes GTP. 
E) The toxin, by altering Gs, keeps intracellular cAMP levels high and doesn't allow them to decrease. 
A) Vibrio cholera bacteria colonize the gut. 
B) Cholera toxin is secreted by Vibrio cholera bacteria. 
C) The cholera toxin causes the cells of the gut to take in salts and fluids. 
D) Cholera toxin alters Gs so that it no longer hydrolyzes GTP. 
E) The toxin, by altering Gs, keeps intracellular cAMP levels high and doesn't allow them to decrease.

Question 20

Explain how caffeine,a methylxanthine,works to stimulate bronchodilation in asthma.

Accepted Answer

Caffeine and theophylline (commonly pres

Exam 14: Signal Transduction Mechanisms: Iimessengers and Receptors

Synthetic compounds that inhibit receptors by preventing the natural messenger from binding are known as

In situations where signaling pathway components need to be "fixed" in a particular position within the cell (e.g.,in the yeast mating pathway),they are associated with ________.

The α-subunit of a heterotrimeric G protein is active when bound to ________.

________ are genetically engineered proteins that allow cytosolic calcium fluxes to be observed by an increase in fluorescence.

Compare and contrast cell signalling via receptor serine/threonine kinases and Ras.

Which of the following signalling proteins is specifically associated with development in animals?

When nitric oxide is used in the dilation of smooth muscle cells,which of the following would interfere with the relaxation of the smooth muscle cells? Inhibitors of

Which of the following statements concerning the properties of ligands for intracellular receptor systems is correct?

The kinase central to second messenger signalling based cAMP is

You obtain two different preparations of XFF,one of which contains the receptors for XFF.You perform a binding assay and obtain a standard curve.Based upon this data,what value would reflect the affinity of the receptor for the ligand? (Assume a 1 XFF-to-1 receptor interaction.)

Which of the following pairings is not correct?

In designing a new drug that may interfere with G-protein coupled receptor interacting protein functions,one possible target for drug action is not

Which of the following would be characterized as a juxtacrine signal?

In heterotrimeric G proteins,the ________ subunit stimulates adenylyl kinase.

________ is the second messenger associated with the regulation of blood pressure.

A type of programmed cell death associated with DNA fragmentation and caspases is known as ________.

Which of the following statements regarding the Ras protein is false?

Prostaglandins are not

G protein-adenyl cyclase activity has been shown,in some cases,to be associated with certain diseases.In the case of cholera,which of the following is not correct?

Explain how caffeine,a methylxanthine,works to stimulate bronchodilation in asthma.

A Preview of the Cell

The Chemistry of the Cell

The Macromolecules of the Cell

Cells and Organelles

Bioenergetics: the Flow of Energy in the Cell

Enzymes: the Catalysts of Life

Membranes: Their Structure, function, and Chemistry

Transport Across Membranes: Overcoming the Permeability Barrier

Chemotrophic Energy Metabolism: Glycolysis and Fermentation

Chemotrophic Energy Metabolism: Aerobic Respiration

Phototrophic Energy Metabolism: Photosynthesis

The Endomembrane System and Peroxisomes

Signal Transduction Mechanisms: Ielectrical and Synaptic Signaling in Neurons

Cytoskeletal Systems

Cellular Movement: Motility and Contractility

Beyond the Cell: Cell Adhesions, cell Junctions, and Extracellular Structures

The Structural Basis of Cellular Information: DNA, chromosomes, and the Nucleus

The Cell Cycle, DNA Replication, and Mitosis

Sexual Reproduction, meiosis, and Genetic Recombination

Gene Expression: Ithe Genetic Code and Transcription

Gene Expression: Iiprotein Synthesis and Sorting

The Regulation of Gene Expression

Cancer Cells

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