Question 1

Which of the following ligands would not have an intracellular receptor?

Accepted Answer

A) cortisol 
B) retinoic acid 
C) thyroxine 
D) epinephrine 
E) progesterone 
A) cortisol 
B) retinoic acid 
C) thyroxine 
D) epinephrine 
E) progesterone

Question 2

After determining which preparation contained the XFF receptor,you wish to determine the properties of the ligand receptor.Using a radioactive XFF,you wish to determine if the properties are similar to that of epinephrine and the epinephrine receptor.If so,you expect to find the radioactive XFF

Accepted Answer

A) within the cell. 
B) associated with the ER. 
C) on the cell surface. 
D) associated with mitochondria. 
E) in the nucleus. 
A) within the cell. 
B) associated with the ER. 
C) on the cell surface. 
D) associated with mitochondria. 
E) in the nucleus.

Question 3

________ produces the second messenger diacylglycerol (DAG).

Accepted Answer

The answer of ________ produces the second messenger diacylglycerol (DAG)....

Question 4

Which of the following statements is false with regard to G-protein coupled receptors (GPCRs)?

Accepted Answer

A) GPCRs can interact with specific receptor interacting proteins to modify ligand affinity. 
B) Adenylate cyclase is activated. 
C) Phosphodiesterase creates v cAMP molecules in response to moderate cAMP levels. 
D) Protein Kinase A is activated by cAMP. 
E) cAMP signals for its own degradation indirectly. 
A) GPCRs can interact with specific receptor interacting proteins to modify ligand affinity. 
B) Adenylate cyclase is activated. 
C) Phosphodiesterase creates v cAMP molecules in response to moderate cAMP levels. 
D) Protein Kinase A is activated by cAMP. 
E) cAMP signals for its own degradation indirectly.

Question 5

Phosphatases are enzymes that

Accepted Answer

A) add phosphate groups. 
B) are always inhibitory. 
C) do not alter target activity. 
D) remove phosphate groups. 
E) all of the above 
A) add phosphate groups. 
B) are always inhibitory. 
C) do not alter target activity. 
D) remove phosphate groups. 
E) all of the above

Question 6

EGF (epidermal growth factor)activates cell division by binding ________.

Accepted Answer

receptor t

Question 7

Match between columns
                        Premises: hormones acting over long distances
phospholipase C
primary signal associated with platelet activation
protein that, when bound with calcium, can be a second messenger
adenylate cyclase
necessary for the activation of heterotrimeric G proteins
second messenger associated with prevention of penetration of an animal egg by multiple sperm cells
precursor of diacylglycerol
pertussis toxin
monomeric G protein

Accepted Answer

The Answer of calmodulin and inhibition of Gi and catalyzes is...

Question 8

Hydrophobic messengers include which of the following?

Accepted Answer

A) retinoids 
B) cAMP 
C) pertussis toxin 
D) calcium ions 
E) ryanodine 
A) retinoids 
B) cAMP 
C) pertussis toxin 
D) calcium ions 
E) ryanodine

Question 9

If one homogenizes liver cells,separates the membranes from the cytoplasm,and then adds epinephrine to only the cytoplasmic portion,

Accepted Answer

A) cAMP will be produced. 
B) G-proteins will be activated. 
C) adenylyl cyclase will be activated. 
D) calcium ions will be released. 
E) none of the above 
A) cAMP will be produced. 
B) G-proteins will be activated. 
C) adenylyl cyclase will be activated. 
D) calcium ions will be released. 
E) none of the above

Question 10

You argue with one of your fellow students that other features of the protein suggest that the protein is much like EGF.To discredit this,you would show the data obtained with

Accepted Answer

A) radioactive XFF. 
B) binding assay. 
C) use of nonhydrolyzable GTP analogues. 
D) amino acid phosphorylation. 
E) tyrosine kinase inhibition studies. 
A) radioactive XFF. 
B) binding assay. 
C) use of nonhydrolyzable GTP analogues. 
D) amino acid phosphorylation. 
E) tyrosine kinase inhibition studies.

Question 11

MAPKs are activated by

Accepted Answer

A) methylation. 
B) microtubules. 
C) membranes. 
D) mitogens. 
E) methionine. 
A) methylation. 
B) microtubules. 
C) membranes. 
D) mitogens. 
E) methionine.

Question 12

The Gα subunit is responsible for activation of ________.

Accepted Answer

The answer of The Gα subunit is responsible for activation...

Question 13

Which of the following is not a plant hormone?

Accepted Answer

A) brassinosteroids 
B) ethylene 
C) abscisic acid 
D) auxin 
E) allomone 
A) brassinosteroids 
B) ethylene 
C) abscisic acid 
D) auxin 
E) allomone

Question 14

Which hormone is not an amino acid derivative?

Accepted Answer

A) histamine 
B) norepinephrine 
C) prostaglandin 
D) epinephrine 
E) thyroxine 
A) histamine 
B) norepinephrine 
C) prostaglandin 
D) epinephrine 
E) thyroxine

Question 15

You add a large amount of XFF to cultured liver cells.Which of the following might you observe if XFF can bind to human epinephrine receptors?

Accepted Answer

A) increased cell division 
B) decreased protein synthesis 
C) glycogen breakdown 
D) glucose-6-phosphate polymerization 
E) all of the above 
A) increased cell division 
B) decreased protein synthesis 
C) glycogen breakdown 
D) glucose-6-phosphate polymerization 
E) all of the above

Question 16

Blood pressure is regulated by the second messenger

Accepted Answer

A) cAMP. 
B) Ca²⁺. 
C) IP₃. 
D) CO. 
E) NO. 
A) cAMP. 
B) Ca²⁺. 
C) IP₃. 
D) CO. 
E) NO.

Question 17

The key mediators of apoptosis are the ________.

Accepted Answer

The answer of The key mediators of apoptosis are the...

Question 18

Match between columns
                        Premises: DAG
cGMP
IP3
calcium
cAMP

Accepted Answer

The Answer of opens calcium channels and glucose mobilization and is...

Question 19

To have a hormone receptor system that is responsive to changes in hormone concentration,it is useful if the concentration of the hormone is

Accepted Answer

A) always more than 10 times the Kd. 
B) never more than 10 times the Kd. 
C) far below the Kd before the stimulation of hormone secretion. 
D) far above the Kd before the stimulation of hormone secretion. 
E) always constant. 
A) always more than 10 times the Kd. 
B) never more than 10 times the Kd. 
C) far below the Kd before the stimulation of hormone secretion. 
D) far above the Kd before the stimulation of hormone secretion. 
E) always constant.

Question 20

You have recently identified a molecule that you believe to be a ligand associated with a signal transduction mechanism.All you know about this ligand is that chemically it is hydrophilic.As a result,you expect it to interact with its receptor

Accepted Answer

A) at the outer cell surface. 
B) within the cytoplasm of the cell. 
C) within the nucleus of the cell. 
D) on the cytoplasmic side of the plasma membrane. 
E) all of the above 
A) at the outer cell surface. 
B) within the cytoplasm of the cell. 
C) within the nucleus of the cell. 
D) on the cytoplasmic side of the plasma membrane. 
E) all of the above

Exam 14: Signal Transduction Mechanisms: Iimessengers and Receptors

Which of the following ligands would not have an intracellular receptor?

After determining which preparation contained the XFF receptor,you wish to determine the properties of the ligand receptor.Using a radioactive XFF,you wish to determine if the properties are similar to that of epinephrine and the epinephrine receptor.If so,you expect to find the radioactive XFF

________ produces the second messenger diacylglycerol (DAG).

Which of the following statements is false with regard to G-protein coupled receptors (GPCRs)?

Phosphatases are enzymes that

EGF (epidermal growth factor)activates cell division by binding ________.

Hydrophobic messengers include which of the following?

If one homogenizes liver cells,separates the membranes from the cytoplasm,and then adds epinephrine to only the cytoplasmic portion,

You argue with one of your fellow students that other features of the protein suggest that the protein is much like EGF.To discredit this,you would show the data obtained with

MAPKs are activated by

The Gα subunit is responsible for activation of ________.

Which of the following is not a plant hormone?

Which hormone is not an amino acid derivative?

You add a large amount of XFF to cultured liver cells.Which of the following might you observe if XFF can bind to human epinephrine receptors?

Blood pressure is regulated by the second messenger

The key mediators of apoptosis are the ________.

To have a hormone receptor system that is responsive to changes in hormone concentration,it is useful if the concentration of the hormone is

You have recently identified a molecule that you believe to be a ligand associated with a signal transduction mechanism.All you know about this ligand is that chemically it is hydrophilic.As a result,you expect it to interact with its receptor

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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