<p>1) When nitric oxide is used in the dilation of smooth muscle cells, which of
ID: 15631 • Letter: #
Question
<p>1) 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 <br />A) calcium release by the ER. <br />B) nitric oxide. <br />C) guanylyl cyclase. <br />D) calmodulin. <br />E) all of the above <br /><br /><br />3) All of the following are second messengers except<br />A) calcium ions.<br />B) IP3.<br />C) DAG.<br />D) cameleons.<br />E) PDGF.<br /><br /><br />5) Hydrophobic messengers include which of the following?<br />A) retinoids<br />B) cAMP<br />C) pertussis toxin<br />D) calcium ions<br />E) ryanodine<br /><br />7) Which of the following would be characterized as a juxtacrine signal?<br />A) contact-dependent<br />B) endocrine<br />C) self-responding<br />D) distal neighbors<br />E) both choices B and D<br /><br /><br />9) Which of the following ligands would not have an intracellular receptor?<br />A) cortisol<br />B) retinoic acid<br />C) thyroxine<br />D) epinephrine<br />E) progesterone<br /><br /><br /><strong>Base your answers to the questions below on the following information:</strong><br /><br /><strong>You have isolated a factor from the blood of a space alien and named it XFF (for X-files factor). Based on preliminary data, you think that XFF could be one of three compounds normally found in human blood: epidermal growth factor (EGF), epinephrine, or estrogen.</strong><br /><br />11) 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.) <br />A) Kd <br />B) Bmax <br />C) Kd - Bmax <br />D) <br />E) The affinity cannot be detertmined from the information available<br /><br /><br />13) 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? <br />A) increased cell division <br />B) decreased protein synthesis <br />C) glycogen breakdown <br />D) glucose-6-phosphate polymerization <br />E) all of the above <br /><br /><br />15) 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 <br />A) within the cell. <br />B) associated with the ER. <br />C) on the cell surface. <br />D) associated with mitochondria. <br />E) in the nucleus. <br /><br /><br />17) Which of the following pairings is not correct? <br />A) adenylyl cyclase-ATP <br />B) phospholipase C-diacylglycerol (DAG) <br />C) phospholipase C-inositol triphosphate <br />D) calmodulin-calcium ions <br /><br /><br />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? <br />A) Vibrio cholera bacteria colonize the gut. <br />B) Cholera toxin is secreted by Vibrio cholera bacteria. <br />C) The cholera toxin causes the cells of the gut to take in salts and fluids. <br />D) Cholera toxin alters Gs so that it no longer hydrolyzes GTP. <br />E) The toxin, by altering Gs, keeps intracellular cAMP levels high and doesn't allow them to decrease. <br /><br /><br />21) You are testing a drug that might be marketed as an anti-inflammatory agent. It would be a good choice if it possessed which of the following responses? <br />A) stimulates the release of prostaglandins <br />B) blocks adenylate cyclase activity <br />C) blocks an enzyme associated with arachidonic acid production <br />D) stimulates the activation of platelets <br />E) all of the above <br /><br /><br />23) Kinases and phosphatases are essential in the cell because they <br />A) help turn proteins "on and off" through changes in phosphorylation status. <br />B) are enzymes that destroy damaged proteins. <br />C) sense short poly-A tails in mRNA as a signal to degrade the mRNA. <br />D) destroy second messengers, thereby turning off a signal transduction pathway. <br />E) all of the above <br /><br /><br />25) A developing organism's failure to produce muscle tissue is most likely due to <br />A) underdevelopment of the ectoderm. <br />B) underdevelopment of the endoderm. <br />C) fibroblast growth factor receptor mutations. <br />D) adenylate cyclase mutations. <br />E) missing chromosomes. <br /><br /><br />27) Prostaglandins are not <br />A) endocrine hormones. <br />B) important in smooth muscle function. <br />C) paracrine hormones. <br />D) stimulators of inflammation. <br />E) formed from arachidonic acid. <br /><br />29) 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 <br />A) at the outer cell surface. <br />B) within the cytoplasm of the cell. <br />C) within the nucleus of the cell. <br />D) on the cytoplasmic side of the plasma membrane. <br />E) all of the above <br /><br />31) You wish to determine if cytosolic calcium fluxes are associated with signal transduction in a particular cell type. One means of observing the calcium fluxes would be to utilize <br />A) caspases. <br />B) cytochrome c. <br />C) nitric oxide. <br />D) radioactive cAMP. <br />E) cameleons. <br /><br /><br />33) IP3 receptors are associated with <br />A) plasma membranes. <br />B) intracellular membranes. <br />C) mitochondrial membranes. <br />D) ER membranes. <br />E) lysosomes. <br /><br />35) Kinases are enzymes that <br />A) add phosphate groups. <br />B) do not alter target activity. <br />C) are always inhibitory. <br />D) remove phosphate groups. <br />E) all of the above<br /><br /><br />37) MAPKs are activated by <br />A) methylation. <br />B) microtubules. <br />C) membranes. <br />D) mitogens. <br />E) methionine. <br /><br /><br />39) All of the following are second messengers, except<br />A) cyclic adenosine monophosphate.<br />B) inositol trisphosphate.<br />C) diacylglycerol.<br />D) epinephrine.<br />E) calcium ions.<br /><br />E) Ras activates a cascade of phosphorylation events.<br /><br /><br />41) Killer lymphocytes can elicit self-destruct mechanisms in target cells by interacting with<br />A) Fas ligand.<br />B) Fas receptors.<br />C) Ras ligand.<br />D) adaptor proteins.<br />E) procaspase.<br /><br /><br />43) Mice lacking the ability to make caspase-9 die as the result of numerous defects. During the necropsy (animal autopsy) of the animal you note that the brains of these mice are<br />A) unregulated growth of the nerve cells.<br />B) lack of apoptosis of some cells.<br />C) overstimulation of G-protein-mediated transduction.<br />D) overproduction of the Etr1 receptor protein.<br />E) all of the above</p>Explanation / Answer
1.a 3.d 5.a 7.a 9.b 11.b 13.c 15.c 17.c 19.c 21.c 23.a 25.e 27.a 29.c 31.c 33.a 35.a 37.d 39.a 41.c 43.b