Question 1

The phospholipid that is hydrolyzed to stimulate ceramide-activated protein kinase is:

Accepted Answer

A)  sphingomyelin. 
B)  phosphatidylinositol-4,5-bisphosphate. 
C)  phosphatidylinositol-4-phosphate. 
D)  phosphatidylcholine. 
E)  phosphatidylinositol. 
A)  sphingomyelin. 
B)  phosphatidylinositol-4,5-bisphosphate. 
C)  phosphatidylinositol-4-phosphate. 
D)  phosphatidylcholine. 
E)  phosphatidylinositol.

Question 2

Discuss the structure of the catalytic core of Protein Kinase A.​

Accepted Answer

Most protein kinases share a common cata

Question 3

Transient increases in cytoplasmic Ca2+ levels can activate all EXCEPT:

Accepted Answer

A)  muscle contraction. 
B)  glucose uptake. 
C)  exocytosis. 
D)  glycogen metabolism. 
E)  all are true. 
A)  muscle contraction. 
B)  glucose uptake. 
C)  exocytosis. 
D)  glycogen metabolism. 
E)  all are true.

Question 4

Which of the following is correctly defined with regards to catecholamines?

Accepted Answer

A)  reserpine increases brain monoamine levels by upregulation of vesicle production 
B)  bromocriptine is a dopamine antagonist linked to some Parkinson's disease indidences 
C)  cocaine binds to monoamine reuptake transporters on the presynaptic membrane thus prolonging the effects of monoamines 
D)  Prozac is a highly specific dopamine reuptake inhibitor 
E)  none of the above 
A)  reserpine increases brain monoamine levels by upregulation of vesicle production 
B)  bromocriptine is a dopamine antagonist linked to some Parkinson's disease indidences 
C)  cocaine binds to monoamine reuptake transporters on the presynaptic membrane thus prolonging the effects of monoamines 
D)  Prozac is a highly specific dopamine reuptake inhibitor 
E)  none of the above

Question 5

Which of the following statements regarding neurons and the action potential is NOT true?

Accepted Answer

A)  efflux of K+ ions leads to a brief hyperpolarization of the cell membrane 
B)  the resting membrane potential is approximately −80mV 
C)  sodium ions that enter an axon through sodium channels in a given axonal region diffuse further along the axon, depolarizing the next axonal region 
D)  in myelinated axons, sodium channels are distributed evenly 
E)  all of the above are true 
A)  efflux of K+ ions leads to a brief hyperpolarization of the cell membrane 
B)  the resting membrane potential is approximately −80mV 
C)  sodium ions that enter an axon through sodium channels in a given axonal region diffuse further along the axon, depolarizing the next axonal region 
D)  in myelinated axons, sodium channels are distributed evenly 
E)  all of the above are true

Question 6

Receptor tyrosine kinases have been called ____ as a result of their ____ and ____.

Accepted Answer

A)  membrane-associated allosteric enzymes; induced conformation changes; oligomeric interactions 
B)  adrenergic receptors; binding insulin; binding epinephrine 
C)  GTP-binding proteins; GTPase activity; guanylyl cyclase activity 
D)  multi-TMS receptors; complex structure; G-protein binding 
E)  none of the above 
A)  membrane-associated allosteric enzymes; induced conformation changes; oligomeric interactions 
B)  adrenergic receptors; binding insulin; binding epinephrine 
C)  GTP-binding proteins; GTPase activity; guanylyl cyclase activity 
D)  multi-TMS receptors; complex structure; G-protein binding 
E)  none of the above

Question 7

In a neuron, when voltage-gated Na+ channels have just closed, which of the following is true?

Accepted Answer

A)  the membrane is less polarized than at rest 
B)  the membrane is more polarized than at rest 
C)  the membrane is polarized to the same degree as at rest 
D)  the membrane is hyperpolarized 
E)  none of the above are true 
A)  the membrane is less polarized than at rest 
B)  the membrane is more polarized than at rest 
C)  the membrane is polarized to the same degree as at rest 
D)  the membrane is hyperpolarized 
E)  none of the above are true

Question 8

Which of the following is a G-protein coupled receptor?

Accepted Answer

A)  EGF receptor 
B)  insulin receptor 
C)  atrial natriuretic peptide receptor 
D)  inhibitory α2-receptor 
E)  EPO receptor 
A)  EGF receptor 
B)  insulin receptor 
C)  atrial natriuretic peptide receptor 
D)  inhibitory α2-receptor 
E)  EPO receptor

Question 9

G-proteins are associated with which receptor superfamily?

Accepted Answer

A)  oligomeric ligand-gated ion channels 
B)  7-transmembrane segment (7-TMS) receptors 
C)  cell adhesion protein receptors 
D)  single-transmembrane segment catalytic receptors 
E)  none of the above 
A)  oligomeric ligand-gated ion channels 
B)  7-transmembrane segment (7-TMS) receptors 
C)  cell adhesion protein receptors 
D)  single-transmembrane segment catalytic receptors 
E)  none of the above

Question 10

Which of the following is not a peptide hormone?

Accepted Answer

A)  adrenocorticotropic hormone 
B)  glucagon 
C)  aldosterone 
D)  calcitonin 
E)  all of the above are peptide hormones 
A)  adrenocorticotropic hormone 
B)  glucagon 
C)  aldosterone 
D)  calcitonin 
E)  all of the above are peptide hormones

Question 11

Calmodulin exhibits all of the following characteristics EXCEPT:

Accepted Answer

A)  its conformation is sensitive to Ca++ binding. 
B)  it contains a basic amphiphilic alpha helix which interacts with target proteins. 
C)  it modulates the activity of many protein kinases. 
D)  it contains one or more helix-loop-helix motifs (EF-hands) which bind the Ca++ ion. 
E)  all are characteristics. 
A)  its conformation is sensitive to Ca++ binding. 
B)  it contains a basic amphiphilic alpha helix which interacts with target proteins. 
C)  it modulates the activity of many protein kinases. 
D)  it contains one or more helix-loop-helix motifs (EF-hands) which bind the Ca++ ion. 
E)  all are characteristics.

Question 12

The effects of ethanol on the brain arise in part from opening of ____ receptor Cl− channels.

Accepted Answer

A)  glycine 
B)  aspartate 
C)  glutamate 
D)  γ-aminobutyrate (GAB
A)  
E)  all are true 
A)  glycine 
B)  aspartate 
C)  glutamate 
D)  γ-aminobutyrate (GAB
A)  
E)  all are true

Question 13

Phospholipase C-γ is activated by ____ while phospholipase C-β is activated by ____.

Accepted Answer

A)  receptor tyrosine kinase; Gα 
B)  receptor tyrosine kinase; cAMP 
C)  nitric oxide; Gα 
D)  protein kinase A; cAMP 
E)  none of the above 
A)  receptor tyrosine kinase; Gα 
B)  receptor tyrosine kinase; cAMP 
C)  nitric oxide; Gα 
D)  protein kinase A; cAMP 
E)  none of the above

Question 14

How does extracellular hormone binding activate intracellular tyrosine kinase activity?

Accepted Answer

A)  conformational change induced active site activation 
B)  conformational change induced oligomeric association and phosphorylation 
C)  induced mRNA synthesis 
D)  activation of specific phospholipases 
E)  all are true 
A)  conformational change induced active site activation 
B)  conformational change induced oligomeric association and phosphorylation 
C)  induced mRNA synthesis 
D)  activation of specific phospholipases 
E)  all are true

Question 15

Rapid influx of Ca++ into the cytoplasm can occur as a result of the binding of hormones to a receptor activating phospholipase C activity. The increased level of Ca++ is derived from all of the following EXCEPT:

Accepted Answer

A)  lysozymes. 
B)  calciosomes. 
C)  endoplasmic reticulum. 
D)  extracellular stores through Ca++ channels in the plasma membrane. 
E)  all of the above. 
A)  lysozymes. 
B)  calciosomes. 
C)  endoplasmic reticulum. 
D)  extracellular stores through Ca++ channels in the plasma membrane. 
E)  all of the above.

Question 16

Which of the following doe NOT correctly pair a hormone with its function?

Accepted Answer

A)  ACTH − promotes production of thyroxin 
B)  calcitonin − regulates plasma Ca2+ 
C)  FSH − stimulates processes within the gonads 
D)  insulin − regulates metabolism and blood glucose 
E)  prolactin − stimulates milk production 
A)  ACTH − promotes production of thyroxin 
B)  calcitonin − regulates plasma Ca2+ 
C)  FSH − stimulates processes within the gonads 
D)  insulin − regulates metabolism and blood glucose 
E)  prolactin − stimulates milk production

Question 17

Discuss the Ras protein and the effect of mutation on the ras genE.​

Accepted Answer

​The normal, cellular Ras protein is a G

Question 18

Acetylcholinesterase:

Accepted Answer

A)  catalyzes synthesis of acetylcholine. 
B)  is regulated by binding of cocaine. 
C)  hydrolyzes acetylcholine inside the presynaptic cell. 
D)  normally functions to prolong stimulation of the postsynaptic cell. 
E)  must be secreted into the synaptic cleft. 
A)  catalyzes synthesis of acetylcholine. 
B)  is regulated by binding of cocaine. 
C)  hydrolyzes acetylcholine inside the presynaptic cell. 
D)  normally functions to prolong stimulation of the postsynaptic cell. 
E)  must be secreted into the synaptic cleft.

Question 19

All are components of the G-protein-coupled receptors (GPCRs) hormone signal transduction unit EXCEPT:

Accepted Answer

A)  protein kinase A. 
B)  adenylyl cyclase. 
C)  hormone receptor. 
D)  G-protein. 
E)  all of the above. 
A)  protein kinase A. 
B)  adenylyl cyclase. 
C)  hormone receptor. 
D)  G-protein. 
E)  all of the above.

Question 20

All are unifying features of polypeptide hormones EXCEPT that they are:

Accepted Answer

A)  originally synthesized with signal sequences. 
B)  synthesized as inactive preprohormones. 
C)  activated from preprohormones to hormones by phosphorylation. 
D)  may produce several different peptide hormones with suitable processing. 
E)  all are true. 
A)  originally synthesized with signal sequences. 
B)  synthesized as inactive preprohormones. 
C)  activated from preprohormones to hormones by phosphorylation. 
D)  may produce several different peptide hormones with suitable processing. 
E)  all are true.

Exam 32: The Reception and Transmission of Extracellular Information

The phospholipid that is hydrolyzed to stimulate ceramide-activated protein kinase is:

Discuss the structure of the catalytic core of Protein Kinase A.​

Transient increases in cytoplasmic Ca2+ levels can activate all EXCEPT:

Which of the following is correctly defined with regards to catecholamines?

Which of the following statements regarding neurons and the action potential is NOT true?

Receptor tyrosine kinases have been called ____ as a result of their ____ and ____.

In a neuron, when voltage-gated Na+ channels have just closed, which of the following is true?

Which of the following is a G-protein coupled receptor?

G-proteins are associated with which receptor superfamily?

Which of the following is not a peptide hormone?

Calmodulin exhibits all of the following characteristics EXCEPT:

The effects of ethanol on the brain arise in part from opening of ____ receptor Cl− channels.

Phospholipase C-γ is activated by ____ while phospholipase C-β is activated by ____.

How does extracellular hormone binding activate intracellular tyrosine kinase activity?

Rapid influx of Ca++ into the cytoplasm can occur as a result of the binding of hormones to a receptor activating phospholipase C activity. The increased level of Ca++ is derived from all of the following EXCEPT:

Which of the following doe NOT correctly pair a hormone with its function?

Discuss the Ras protein and the effect of mutation on the ras genE.​

Acetylcholinesterase:

All are components of the G-protein-coupled receptors (GPCRs) hormone signal transduction unit EXCEPT:

All are unifying features of polypeptide hormones EXCEPT that they are:

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, Tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Membranes and Membrane Transport

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Enzymeskinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Metabolism: an Overview

Glycolysis

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Lipid Biosynthesis

Nitrogen Acquisition and Amino Acid Metabolism

Synthesis and Degradation of Nucleotides

Metabolic Integration and Organ Specialization

Dna Metabolism: Replication, Recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

Completing the Protein Life Cycle: Folding, Processing, and Degradation

Filters

Discuss the structure of the catalytic core of Protein Kinase A.

Transient increases in cytoplasmic Ca²⁺ levels can activate all EXCEPT:

Receptor tyrosine kinases have been called as a result of their and .

In a neuron, when voltage-gated Na⁺ channels have just closed, which of the following is true?

Phospholipase C-γ is activated by while phospholipase C-β is activated by .

Rapid influx of Ca⁺⁺ into the cytoplasm can occur as a result of the binding of hormones to a receptor activating phospholipase C activity. The increased level of Ca⁺⁺ is derived from all of the following EXCEPT:

Discuss the Ras protein and the effect of mutation on the ras genE.