BiochemistryTestchapters13-27,学生考题汇总.doc

19Biochemistry Test (part 2: chapters 13 to 27)Name Student ID Score IIIIIIIVTotalI Write structures (2.5 x 4 = 10)(1) NADP+ (2) CoA (3) lipoic acid (4) QH2 (5) ATP (6) Creatine phosphate (7) carnitine (8) cAMP(9) GSH (10) PLP (11) QH2 (12) SAM(13) glyphosate (14) glycocholate (15) atrazine (16) hypoxanthine(17) methotrexate (18) allopurinol (19) phophatidate (20)activated diacylglycerol(21) cardiolipin (22) N-glycolylneuraminate (23) mevalonate (24) lovastatin II Multiple choices (2 x 35=70)1. Electrons from cytoplasmic NADH can enter the mitochondrial electron-transport chain through glycerol 3-phosphate shuttle, generating molecules of ATP per one NADH when the electrons are transferred to oxygen. (A) 1.5 (B) 2.5 (C) 3.5 (D) 02. The uptake of lactose by lactose permease is driven by in E.coli.(A) ATP hydrolysis (B) H+ gradient across the membrane (C) a protein complex not examined intensively (D) -3. Approximately 50% of the therapeutic drugs that we use target receptors. (A) insulin (B) epidermal growth factor (C) epinephrine (D) G-protein coupled4. Phosphorylation of pyruvate dehydrogenase will_ the enzyme. (A) activate (B) inactivate (C) destroy (D) stabilize5. G protein, a heterotrimer consisting a,b and g subunits, is anchored to the membrane by .(A) transmembrane helix (B) transmembrane b-stand (C) covalently attached fatty acids (D) the interaction with receptors6. Angiotensin II receptor, a peptide hormone, controls blood pressure through . (A) cAMP cascade (B) CaM (C) phosphoinositide cascade (D) cGMP7. Both second messengers inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) can be generated through the cleavage of PIP2 with . (A) the activative IP3 synthase (B) the activative b isoform of phospholipase C (C) the activative PIP2 synthase (D) the activative phopholipase A8. Fura-2 is a fluorescent dye used in the monitoring the concentration of calcium in real time. When the regents bind to calcium, their fluorescent properties .(A) will be changed (B) are maintained but the fluorescent intensities are changed (C) are maintained (D) will be improved9. Protein kinase A (PKA) consists of two regulatory (R) chains and two catalytic (C) chains, i.e. R2C2. The complex will be catalytically inactive the regulatory chains bind to cAMPs.(A) unless (B) if (C) although (D) or10. EF-hand protein family contains EF hand, which is a Ca2+ -binding motif that consists of .(A) an E hand and an F hand (B) an E finger and an F finger(C) an E loop and an F helix (D) a helix, a loop, and a second helix 11. Insulin receptor has tyrosine kinase activity, which is controlled by an unstructured loop (called the activation loop). When the loop is phosphorylated, the receptor kinase . (A) is inactive (B) is active (C) binds insulin (D) does not bind insulin12. The phosphotyrosine residues in the IRS proteins can be recognized by proteins containing domain. (A) SH2 (B) SH3 (C) EF hand (D) tyrosine phosphorylation13. Phosphorylation of aspartate residue is required for the transportation of some ions such as calcium by . (A) P-type ATPase (B) N-loop ATPase (C) Glucose transporter (D) all above14. The EGF receptor, a dimer of two identical units, binds .(A) one EGF molecule (B) two EGF molecules (C) three EGF molecules (D) four EGF molecules15. Calmodulin-dependent protein kinases (CaM kinases) will be active when .(A) CAM devoid of calcium (B) CAM binds to calcium(C) CaM concentration is high enough (D) CaM is modified with carbohydrates16. Catabolism is a term for those reactions that . (A) require energy for synthesis of biomolecules (B) transform fuels into cellular energy (C) involve energy transformation in vivo (D) convert molecules in vivo17. Cellular energy transformation can be mediated by .(A) phosphoryl-transfer potential (B) electrons captured by NAD+ or FAD (C) ion gradients across membranes (D) all above18. Most reductive biosyntheses are carried out with the electrons from . (A) NADH (B) NADPH (C) FADH2 (D) QH219. Biotin is a vitamin that can be transformed into biotin-lysine adducts, the coenzymes for .(A) reduction (B) acyl group transfer (C) carboxylation (D) methyl transfer20. Scurvy is caused by the deficiency of vitamin .(A) A (B) B (C) C (D) D21. The opening and closing of individual ion channels can be measured by .(A) PCR (B) affinity chromatography (C) patch-clamp technique (D) fluorescent staining22. In eukaryotes, metabolic regulation and flexibility can be reached by control of . (A) the amounts of enzymes (B) the enzymatic activities. (C) the accessibility of substrates (D) all above23. The binding of glucose induces a large conformational change in yeast hexokinase that consists of two lobes, including . (A) one lobe rotates 12 degrees with respect to the other, and movements of the polypeptide backbone of as much as 8 A (B) enlarging the cleft for ATP accessibility (C) creating a binding site for ATP (D) all above24. The ab barrel of triose phosphate isomerase is composed of eight parallel b strands surrounded by eight a helices. In order to eliminate potential side reactions, a loop is required for . (A) closes off the active site when substrate bound. (B) opens the active site when products formed. (C) (a) and (b) (D) others not mentioned above25. The energy powers the transfer of a phosphoryl group from creatine phosphate to ADP to yield ATP. This process is classified as .(A) oxidative phosphorylation (B) photophosphorylation (C) substrate-level phosphorylation (D) all above26. Rossmann fold, consisting of four a-helices and a sheet of six parallel b-strands, likely represents a primordial domain for that recurs in the dehydrogenases of glycolysis.(A) substrate binding (B) dinucleotide-binding (C) ATP binding (D) GTP binding 27. The conversion of UDP-glucose into UDP-galactose by is essential for the synthesis of galactosyl residues in complex polysaccharides and glycoproteins if the amount of galactose in the diet is inadequate to meet these needs. (A) galactokinase (B) galactose 1-phosphate uridyl transferase (C) UDP-galactose 4-epimerase (D) all above28. The pH might fall when muscle is functioning anaerobically, producing excessive quantities of lactic acid, which would damage muscle. Therefore a strategy is required for preventing accumulation of too much lactic acid. A decrease in pH also inhibits phosphofructokinase activity by. (A) that a decrease in pH augments the inhibitory effect of ATP on PFKinase.(B) that a decrease in pH has the inhibitory effect of ATP on PFKinase. (C) that a decrease in pH augments the inhibitory effect of ATP on hexoKinase. (D) that a decrease in pH has the inhibitory effect of ATP on hexoKinase.29. The rate of formation of is important in determining the overall rate of the cycle. (A) citrate (B) succinate (C) malate (D) a-ketoglutarate 30. The sequence Thr-Val -Gly-Tyr-Gly (TVGYG) which is extended and oriented such that the peptide carbonyl groups are directed into the channel in good position to interact with the ion confers of K+ channels.(A) ion solubility (B) ion size (C) ion electric charge (D) ion selectivity 31. The intermediates from TCA cycle can be used as the direct precursors of fatty acids.(A) citrate (B) succinate (C) malate (D) a-ketoglutarate 32. Arsenite inhibits the pyruvate dehydrogenase complex by inactivating the dihydrolipoamide component of the transacetylase. can relieve the inhibition by forming a complex with the arsenite that can be excreted.(A) Alanine (B) nucleotides (C) Carbohydrates (D) Sulfhydryl reagents 33. Reactive oxygen species or ROS are those superoxide or hydrogen peroxide.(A) superoxide (B) hydrogen peroxide (C) OH. (D) all above34. When an individual organism is threatened, the hormone is released, which stimulates the mobilization of energy stores and leads to improved cardiac function. (A) insulin (B) epidermal growth factor (C) epinephrine (D) ion selectivity 35. Each cycle of glyoxylate cycle requires _ molecule(s) of acetyl-CoA.(A) 1 (B) 2 (C) 3 (D) 436. Fructose can cyclize to (a) primarily.A)pyranose ring. B)furanose ring. C)both pyranose and furanose ring forms.D)All of the above. E)None of the above. 37. As they can block releasing of viral particles from host cells, inhibitors of are important anti-influenza agents . A)glycosidase B)protease C)nuclease D) glycosyl transferase E) neuroaminidase (sialidase) 38. The transmembrane helices can be predicted by calculation the free energy change that takes place when a hypothetical a-helix formed of residues n to n + is transferred from membrane interior to water. A)15 B)17 C)19 D) 21 E) 2339. Ca2+ ATPase transfers phophoryl group from ATP to the side chain of residue(s) in P-domain. A)Tyr B)Ser C)Thr D)Asp E)Glu. 40. Channels that open in response to membrane depolarization are called _ channels. A) voltage-gated B)symport C)ligand-gated D)All of the above. E)None of the above.41. In addition to dissociation of epinephrine-receptor complex, are involved in resetting the receptors. A) b-adrenergic receptor kinase B)b-arrestin C)G-protein D)a and b E)a, b, and c 42. The fluorescent proterties of Fura-2 are changed on binding calcium through . A) positioning oxygen atoms of Fura-2 B)modifying Fura-2 C)cleaving Fura-2 D)covalently binding Fura-2 E)an unknown mechanism 43. Phospotyrosine residue are recognized by and bound to other proteins that contain a domain. A)SH1 B)SH2 C) SH3 D) EF-handin E) None of the above 44. The reason for bound GTP considered as a “clock” is the GTP . A)behaves in specific time intervals B) is hydrolyzed by the intrinsic GTPase activity of the Ga receptors C)is regulated by energy D)All of the above E)None of the above. .45. Example(s) of disease(s) caused by altered G-protein activity is (are) . A)whooping cough. B)cholera. C)bubonic plague. D) a and b. E) a and c. 46. The major purpose(s) for organisms require energy is (are) . A)performance of mechanical work B)active transport C)synthesis of biomolecules D)a and c E)a, b, and c 47. The substance(s) have a higher phosphoryl-transfer potential than ATP. A)phosphoenolpyruvate B)creatine phosphate C)1,3-bisphosphoglycerate D)a and b E)a, b, and c 48. The substance is the electron donor used for reductive biosynthesis. A)NADH B)CoASH C)NADPH D)ATP E) FADH2 49. Metabolic processes are regulated by . A)transcriptional regulation of the amount of enzyme. B)allosteric control of enzyme activity. C)Accessibility of substrates by compartmentalization. D)a and b. E)a, b, and c. 50. Reducing sugars are those that can transfer into red precipitate.A) Feelings solution B)Sangers solution C)Fehlings solutionD) Edmans solution E)Yellows solution 51. Mucopolysaccharidoses is the name given to a collection of diseases that result from the inability to degrade . A) glycogen B)glycosaminoglycans C)glucose D)lactose E) glycoproteins 52. Oligosaccharides are assembled in the reactions catalyzed by . A)glycosyl-ligase B)monosaccharide-ligase C)monosaccharide-transferase D)glycosyl-transferases E) glycosidase53. The side chains of residues are glycosylated in glycoproteins.A)Asp, Thr, and Ser B)Asn, Thr, and Ser C)Gln, Thr, and Ser D)Tyr, Thr, and Ser E) Asn, Tyr, Thr, and Ser54. Engineered EPO in Ecoli has only 10% of the bioactivity of the glycosylated ones because they .A)bind their receptors inefficiently B)have incorrect structure C)are removed rapidly in vivo D)are modified again in vivo E) are precipitated immediately.55. There are possibility to convert micelle-forming molecules into bilayer ones when the size of hydrophobic tail is . A)enlarged B) the same but temperature is changed C)positively charged D)decreased. E)negatively charged56. In general, membranes performing different functions contains different repertoires of . A)membrane lipids B) membrane proteins C)membrane carbohydrates D)a and b E) a, b, and c57. Some peripheral membranes are anchored to the lipid bilayer by . A) covalently attached a hydrophobic chain B) covalently attached a trans-membrane a-helix C) covalently attached a trans-membrane b-strand D) a and b E)a, b, and c 58. The technique used to evaluate the speed of lateral diffusion is . A)fluorescence recovery B) ultracentrifugation C)patch-clamp D)a and b E) a, b, and c 59. Digitalis specifically inhibits the Na+-K+ ATPase by blocking its . A)phosphorylation B)dephosphorylation C)permeability selectivity D)a and b E)a, b, and c. 60. Protein kinase C is activated by . A)IP3 B) Ca2+ C)DAG D)a and b E)b and c 61. EF hand is a binding site for that used to initiate specific conformational change. A)DNA B)glucose C)Ca2+ D)cAMP E)DAG62. Insulin receptor is a kinase that phosphorylates the side chains of within the substrate proteins. A)Ser or Thr B) Tyr C)a or b D)a and b E)None of the above. 63. The kinase activity of EGF receptor requires . A)EGF binding B)phosporylation of its carboxyl terminal tail C)dimerization D) Grb 2 E)None 64. An enzyme called is used catalyze a metabolic reaction in which a functional group is added across a double bond or removed to form a double bond.A)isomerase B) transferase C)ligase D)lyase E)mutase 65. Hydrolysis of ATP is required for reset for another cycle. A)Ca2+-ATPase B)Na+-K+ ATPase C)ABC D)lactose permease transporters E)glucose transporters.66. The substance is not involved in de novo pyrimidine biosynthesis. (A) bicarbonate (B) aspartate (C) ammonia (D) glutamine (E) glutamate67. There are active sites in carbamoyl phosphate synthetase, which are linked by a channel used for intermediates path from one site to the next. (A) 2 (B) 3 (C) 4 (D) 5 (E) 668. The conserved structure in amido-transferase family is . (A) a dyad comprising a cysteine and a histidine residue (B) a dyad comprising two cysteine residues. (C) a dyad comprising two aspartate residures (D) a triad comprising a histidine, a serine, and a aspartate residue(E) none of the above69. For the conversion of dihydroorotate to orotate, is used as the oxidant.(A) FMN (B) FAD (C) NAD+ (D) NADP+ (E) Q70. The amino group of glutamine provides ammonia to replace O-4 atom of , transforming uridylate derivatives to cytidylate ones. (A) UMP (B) UDP (C) UTP (D) uridine (E) none of the above71. For the de novo purine synthesis, is not included in the starting materials.(A) aspartate (B) glycine (C) PRPP (D) glutamine (E) acetyl-CoA72. Many of the intermediates in the de novo purine biosynthesis pathway degrade rapidly in water, suggesting that . (A) there is an arm responsible for moving the product of one enzyme directly to the next enzyme along the pathway.(B) the product of one enzyme must be channeled directly to the next enzyme along the pathway.(C) the active sites when the enzyme is bond to the substrates are closed immediately until the products formed.(D) the intermediates are actually more stable during the pathway although they are liable in water as the reactions are performed in a special compartment.(E) none of the above.73. The carbonyl oxygen atom at C-6 of inosinate is substituted by an ami