Which of the following is NOT involved in the specificity of signal transduction?
A.) Interactions between receptor and signal molecules
B.) Location of receptor molecules
C.) Structure of receptor molecules
D.) Structure of signal molecules
E.) Transmemb
E.) Transmembrane transport of signal molecules by receptor molecules
Scatchard analysis can provide information on:
A.) Enzyme cascades
B.) Enzyme mechanisms
C.) Gated ion channels
D.) Protein phosphorylation
E.) Receptor-ligand interactions
E.) Receptor-ligand interactions
The force that drives an ion through a membrane channel depends upon:
A.) The charge on the membrane
B.) The difference in electrical potential across the membrane
C.) The size of the channel
D.) The size of the ion
E.) The size of the membrane
B.) The difference in electrical potential across the membrane
The ion channel that opens in response to acetylcholine is an example of a ______ signal transduction.
A.) G Protein
B.) Ligand-gated
C.) Receptor-enzyme
D.) Serpentine receptor
E.) Voltage-gated
B.) Ligand-gated
The effects of acetylcholine on the postsynaptic ion channel are mainly due to:
A.) Cyclic nucleotide synthesis
B.) Protein cleavage(proteolysis)
C.) Protein conformational changes
D.) Protein phosphorylation
E.) Protein synthesis
C.) Protein conformational changes
Which of the following statements concerning signal transduction by the insulin receptor is NOT correct?
A.) Activation of the receptor protein kinase activity results in the activation of additional protein kinases
B.) Binding of insulin to the receptor
E.) The substrates of the receptor protein kinase activity are mainly proteins that regulates transcription
Which of the following statements concerning receptor enzymes is correct?
A.) They are not usually membrane-associated proteins
B.) They contain an enzyme activity that acts upon a cytosolic substrate
C.) They contain an enzyme activity that acts upon the
B.) They contain an enzyme activity that acts upon a cytosolic substrate
Guanyl cyclase receptor enzymes
A.) Are all membrane-spanning proteins
B.) Are examples of ligand-gated ion channels
C.) Catalyze synthesis of a phosphate ester
D.) Catalyze synthesis of a phosphoric acid anhydride
E.) Require hydrolysis of ATP in additio
C.) Catalyze synthesis of a phosphate ester
Serpentine receptors:
A.) Are examples of G (GTP-binding) regulatory proteins
B.) Are mainly involved in the regulation of ion transport
C.) Are present in prokaryotic cells but not in eukaryotic cells
D.) Are present in the nucleus and affect gene expres
E.) Have multiple membrane-spanning helical domains
Protein kinase A (PKA) is:
A.) Activated by covalent binding of cyclic AMP
B.) Affected by cyclic AMP only under unusual circumstances
C.) Allosterically activated by cyclic AMP
D.) Competitively inhibited by cyclic AMP
E.) Non-competitively inhibited by
C.) Allosterically activated by cyclic AMP
Which of the following is NOT involved in signal transduction by the beta-adrenergic receptor pathway?
A.) ATP
B.) Cyclic AMP
C.) Cyclic GMP
D.) GTP
E.) All of the above are involved
C.) Cyclic GMP
Which of the following is NOT involved in signal transduction by the beta-adrenergic receptor pathway?
A.) Cyclic AMP synthesis
B.) GTP hydrolysis
C.) GTP-binding protein
D.) Protein Kinase
E.) All of the above are involved
E.) All of the above are involved
Which of the following does NOT involve cyclic AMP?
A.) Regulation of glycogen synthesis and breakdown
B.) Regulation of glycolysis
C.) Signaling by acetylcholine
D.) Signaling by epinephrine
E.) Signaling by glucagon
C.) Signaling by acetylcholine
Hormone-activated phospholipase C can convert phosphatidylinositol 4,5-biphosphate to:
A.) Diacylglycerol + inositol triphosphate
B.) Diacylglycerol + inositol + phosphate
C.) Glycerol + inositol + phosphate
D.) Glycerol + phosphoserine
E.) Phosphatidyl g
A.) Diacylglycerol + inositol triphosphate
Calmodulin is a(n):
A.) Allosteric activator of calcium-dependent enzymes
B.) Allosteric inhibitor of calcium-dependent enzymes
C.) Calcium-dependent enzyme
D.) Cell surface calcium receptor
E.) Regulatory subunit of calcium dependent enzymes
E.) Regulatory subunit of calcium dependent enzymes
The specificity of signaling pathways includes all of the following except:
A.) Flippase-catalyzed movement of phospholipids from the inner to the outer leaflet
B.) Migration of signal proteins into membrane rafts
C.) Phosphorylation of targets at the Ser
A.) Flippase-catalyzed movement of phospholipids from the inner to the outer leaflet
Which of the following signaling mechanisms is used most predominantly in plants?
A.) Cyclic-nucleotide dependent protein kinases
B.) DNA-binding nuclear steroid receptors
C.) Protein serine/threonine kinases
D.) Protein tyrosine kinases
D.) Protein tyrosine kinases
In the plant signaling pathways employing receptor-like kinases (RLKs), which one of the following does NOT occur?
A.) Activation of a MAPK cascade
B.) Autophosphorylation of receptor
C.) dimerization of receptor
D.) Ligand binding to receptor
E.) Phospho
E.) Phosphorylation of key proteins on Tyr residues
Most transduction systems for hormones and sensory stimuli that involve trimeric G proteins have in common all of the following except:
A.) Cyclic nucleotides
B.) Nuclear receptors
C.) Receptors that interact with a G protein
D.) Receptors with multiple t
B.) Nuclear receptors
Cholera and pertussis toxins are:
A.) Enzyme inhibitors
B.) Enzyme modifiers
C.) Enzymes
D.) G protein signal transduction disrupters
E.) All of the above
E.) All of the above
Steroid hormones are carried on specific carrier proteins because hormones:
A.) Are too unstable to survive in the blood on their own
B.) Cannot dissolve readily in the blood because they are too hydrophobic
C.) Cannot find their target cells without them
B.) Cannot dissolve readily in the blood because they are too hydrophobic
Steroid hormone response elements (HREs) are _______, which when bound to ________, alter gene expression at the level of __________.
A.) Intron sequences; activated hormone receptor; translation
B.) nuclear proteins; hormone; transcription
C.) Plasma mem
E.) Sequences in DNA; receptor-hormone complex; transcription
Which of the following statements concerning cyclin-dependent protein kinases is NOT correct?
A.) Each type of cell contains one specific form (isozyme)
B.) Their activity fluctuates during the cell cycle
C.) Their activity is regulated by changes in gene
A.) Each type of cell contains one specific form (isozyme)
Which of the following statements concerning cyclins in NOT correct?
A.) They are activated and degraded during the cell cycle
B.) They are regulatory subunits for enzymes that catalyze the phosphorylation of proteins
C.) They can become linked to ubiquit
D.) They catalyze the phosphorylation of proteins
Ubiquitin is a:
A.) Component of the electron transport chain
B.) Protease
C.) Protein Kinase
D.) Protein phosphorylase
E.) Protein that tags another protein for proteolysis
E.) Protein that tags another protein for proteolysis
Cyclin-dependent protein kinases can regulate the progression of cells through the cell body by phosphorylation of proteins such as:
A.) Insulin
B.) Myoglobin
C.) Myosin
D.) Retinal rod and cone proteins
E.) All of the above
C.) Myosin
Proto-oncogenes can be transformed to oncogenes by all of the following mechanisms except:
A.) Chemically induces mutagenesis
B.) Chromosomal rearrangements
C.) During a viral infection cycle
D.) Elimination of their start signals for translation
E.) Radi
D.) Elimination of their start signals for translation
Oncogenes are known that encode all of the following except:
A.) Cytoplasmic G proteins and protein kinases
B.) DNA-dependent RNA polymerases
C.) Growth factors
D.) Secreted proteins
E.) Transmembrane protein receptors
B.) DNA-dependent RNA polymerases
What is the order of events in cell signaling?
A.) Transducer, Effector, Response, Signal, Receptor
B.) Response, Effector, Transducer, Receptor, Response
C.) Signal, Receptor,Transducer, Effector, Response
D.) Signal, Response, Transducer, Effector, Rece
C.) Signal, Receptor,Transducer, Effector, Response
Cell membranes are...?
A.) Semipermeable
B.) Permeable
C.) Nonpermeable
A.) Semipermeable
Hydrophobic molecules are...?
A.) Lipophibic
B.) Lipophilic
B.) Lipophilic
Water-hating molecules love fat.
Which system do cells act on themselves using hormones by?
A.) Autocrine
B.) Paracrine
C.) Endocrine
A.) Autocrine
Which system do cells act on adjacent cells using hormones?
A.) Autocrine
B.) Paracrine
C.) Endocrine
B.) Paracrine
Which system do cells secrete hormones into the blood stream by?
A.) Autocrine
B.) Paracrine
C.) Endocrine
C.) Endocrine
Is receptor-ligand binding reversible?
Y/N
Yes. Because it eventually needs to terminate the signal.
Which chemical messenger is NOT in the nervous system?
A.) Acetylcholine
B.) Steroids
C.) Norepinephrine
D.) GABA
B.) Steroids are part of the endocrine system, NOT part of the nervous system.
Acetylcholine, norepinephrine, and GABA are all neurotransmitters that are part of the nervous system.
Which chemical messenger is NOT in the endocrine system?
A.) Thyroid hormones
B.) Steroid hormones
C.) Vitamin D3
D.) Cytokines
D.) Cytokines are NOT in the endocrine system. They are part of the immune system.
Which chemical messenger is NOT in the immune system?
A.) Histamine
B.) Steroid hormones
C.) Eicosanoids
D.) Cytokines
B.) Steroid hormones are NOT part of the immune system. They're part of the endocrine system.
What are some examples of nuclear receptors?
A.) Histamine and Steroid Hormones
B.) Histamine and Cytokines
C.) Steroid Hormones and Thyroid Hormones
D.) Thyroid Hormones and Cytokines
C.) Steroid hormones and thyroid hormones are nuclear receptors.
What are the two general mechanisms of hormone action?
A.) Membrane and Nuclear
B.) Membrane and acetylcholine
C.) Nuclear and acetylcholine
D.) Nuclear and Peptide
A.) Nuclear and Membrane
What hormones are involved in membrane receptors?
A.) Steroid and Thyroid
B.) Peptide and Amine
C.) Peptide and Thyroid
D.) Steroid and Amine
B.) Peptide and amine
Which mechanism produces second messenger molecules?
A.) Nuclear
B.) Membrane
B.) Membrane
Which mechanism is faster?
A.) Nuclear
B.) Membrane
B.) Membrane
Which mechanism causes a cascade of events that leads to a biological response?
A.) Nuclear
B.) Membrane
B.) Membrane
Which mechanism causes specific gene expression?
A.) Nuclear
B.) Membrane
A.) Nuclear
Insulin and Glucagon are examples of...?
A.) Testosterone
B.) Epinephrine
C.) Peptide
D.) Nitric Oxide
C.) Peptide
A high concentration of ligands may cause what?
A.) Receptor stimulation
B.) Cell destabilization
C.) Receptor burn-out
D.) Receptor desensitization
D.) Receptor desensitization
ATP binds to andenylate cyclase to produce what?
A.) Cyclic GMP
B.) Cyclic AMP
C.) ATP
D.) GDP
B.) Cyclic AMP
What is down regulation?
A.) Receptors are internalized by endocytosis and are unavailable to bind
B.) Receptors are destroyed by inflammation and are unable to bind
C.) Receptors are deformed so that they can no longer bind
A.) Receptors are internalized by endocytosis and are unavailable to bind
What are some examples of second messengers? (MACA)
A.) Cyclic AMP
B.) Steroids
C.) Ca2+
D.) cGMP
E.) IP3
A,C,D,E
Cyclic AMP, Ca2+, cGMP, IP3
What terminates signals?
A.) Cyclic AMP
B.) GMP
C.) Phosphodiesterase
D.) Phosphotriesterase
C.) Phosphodiesterase
What do phosphodiesterase inhibitors do?
A.) Prevent the breakdown of cAMP/cGMP
B.) Prevent the separation of gamma and beta parts on G proteins
C.) Dance the boogie
D.) Prevents ligand binding to substrates in the membrane
A.) Prevent the breakdown of cAMP/cGMP
Which of the following are G-Protein receptors? (MACA)
A.) Acetylcholine Muscarinic Receptors
B.) GABAb
C.) Glucagon
D.) Adrenergic
E.) Steroids
A,B,C,D
Steroids are not G-protein receptors
The function of protein kinase is to activate...?
A.) Steroid phosphorylation
B.) GABA dislocation
C.) cAMP secretion
D.) Protein phosphorylation
D.) Protein phosphorylation
How does cAMP activate protein kinase?
A.) cAMP binds to regulatory subunit, causing separation of the catalytic subunit so that it becomes active and cause phosphorylation
B.) cGMP binds to regulatory subunit, causing separation of the catalytic subunit
A.) cAMP binds to regulatory subunit, causing separation of the catalytic subunit so that it becomes active and cause phosphorylation