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11)All chiral D-sugars rotate plane-polarized light: A)clockwise. B)counterclockwise. C)+20.0°. D)in a direction that cannot be predicted but must be determined experimentally. E)since they are optically inactive. 12)What is the relationship between the following compounds? D-erythroseL-erythrose A)conformational isomers B)constitutional isomers C)identical D)enantiomers E)diastereomers 13)What is the definition of an epimer? 14)At which.
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11)Which of the following residues acts as a general-base catalyst in the cleavage of the C3-C4 bond in the mechanism of the aldolase-catalyzed reaction? A)Methionine B)Histidine C)Cysteine D)Asparagine E)Lysine 12)Which of the following residues acts as a general-acid catalyst in aldolase but as a general-base catalyst in chymotrypsin? A)Methionine B)Histidine.
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31)What structural feature do most effective antihistamines have in common with histamine and how is this common feature believed to be related to the effectiveness of antihistamines as drugs? 32)What name is given to the receptors involved in neurotransmission, memory, and wakefulness? A)cholinergic receptors B)beta-blockers C)histamine receptors D)prostaglandin receptors E)opiate.
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41)Which of the following statements best describes what an "electron sink" is? A)a free radical initiator for enzyme catalysis B)a site for electron localization C)a site for electron delocalization D)a site that donates electrons for enzyme catalysis E)a site that accepts electrons for enzyme catalysis 42)In addition to TPP, which.
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  1.1   Multiple Choice Questions 1) An element has three stable isotopes with masses of 27.977 amu, 28.976 amu, and 29.973 amu.  The heavier two isotopes have an abundance of 4.68% and 3.09%, respectively.  What is the mass of the element? A) 27.684 amu B) 29.251 amu C) 28.085 amu D) 30.107 amu E) 28.991 amu 2) All.
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21) Two or more substances in variable proportions, where the composition is constant throughout are A) a compound. B) an element. C) a heterogeneous mixture. D) a homogeneous mixture. E) a crystalline solid. 22) Two or more substances in variable proportions, where the composition is variable throughout are A) a solution. B) a homogeneous mixture. C) a compound. D).
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51)Which of the following reactions is called an α, β-elimination of an amino acid? A)I B)II C)III D)IV E)V 52)Show the transimination (trans-Schiffization) reaction that happens in all PLP-requiring enzymes in which the amino acid substrate forms a Schiff base with PLP, thereby freeing the lysine side chain.  53)Which of.
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1)Which of the following molecules is the skeletal structure of an amino acid? A) B) C) D) E) 2)Which polymers are the most prevalent in nature? A)polysaccharides B)nucleic acids C)proteins D)C only E)A, B, and C 3)Which of the following describes the side chain for Alanine? A)hydrogen B)ethyl group C)methyl.
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41)What is the product obtained from the mild oxidation of the thiol shown below? 2 R?SH Thiol A)R-S-R B)R-OH C)R-S-S-R D)R-OO-R E)R-S-OH 42)Which labeled bond in the following molecule is known as the peptide bond? A)1 B)2 C)3 D)4 E)5 43)Draw the dipeptide Val-Tyr at pH 7.0. 44)When a disulfide linkage is formed,.
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  91)Deduce the identity of the following compound from the spectral data given. C9H10O2: 13C NMR, δ 18.06 (quartet), 45.40 (doublet), 127.32 (doublet), 127.55 (doublet), 128.61 (doublet), 139.70 (singlet), 180.98 (singlet); IR, broad 3500-2800, 1708 cm-1 92)Deduce the identity of the following compound from the spectral data given. C5H10O: 1H NMR,.
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17)Which of the following enyzmes are used to catalyze glycolysis? I.enolase II.glycerol kinase III.aldolase IV.glycerol-3-phosphate dehydrogenase V.acyl-CoA dehydrogenase VI.?-ketoacyl-CoA thiolase VII.enoyl-CoA hydratase               VIII.hexokinase IX.pyruvate kinase X.phosphoglyceromutase XI.3-L-hydroxyacyl-CoA dehydrogenase A)II, IV, VI, VII, IX B)I, III, VIII, IX, X C)I, V, VII, VIII, X D)III, V, VI, VII, IX E)II, IV, VII, VIII, X 18)Describe the first stage of carbohydrate catabolism? 19)Describe.
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61)Which of the following vitamins catalyzes one-carbon transfer reactions and requires THF as a coenzyme? A)biotin B)thiamine C)folic acid D)ascorbic acid E)panthothenate 62)Which of the following is required for clotting of the blood in the human body? A)vitamin D B)vitamin K C)vitamin B6 D)vitamin A E)vitamin B12 63)Which of the.
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11)The α-carbon of all the amino acids is a chirality center except for __________. A)Glycine B)Threonine C)Proline D)Aspartic acid E)Arginine 12)Explain what essential amino acids are and list all of them. 13)Which of the following terms best describes the side chain of valine? A)acidic B)basic C)charged, polar D)uncharged, polar E)nonpolar.
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21)Which coenzyme is used by enzymes to catalyze oxidation reactions? A)NADH B)NAD+ C)FAD D)THF E)B and C 22)In a process known as oxidative phosphorylation, every NADH that is formed in carrying out oxidation reactions in the early stages of catabolism is converted into __________. A)three ATPs B)two ATPs C)four FADHs.
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11)What is the major structural difference between a ribonucleoside and a ribonucleotide? 12)Besides a possible difference in base structure, what is the major structural difference between ribo- and deoxyribonucleosides? 13)Name the two pyrimidine bases which serve as components in deoxyribonucleotides. 14)Name the two purine bases which serve as components in.
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31)What are the main structural and functional differences between NAD+/NADH and NADP+/NADPH? 32)Explain why a cell typically maintains its [NAD+]/[NADH] ratio near 1000 while maintaining its [NADP+]/[NADPH] ratio at about 0.01. 33)How does NAD+ serve as a catalyst in oxidation reactions? A)It accepts a hydride ion at the 4-position of.
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1)Describe the functional group features of a carbohydrate. 2)Explain when the term "aldose" is used. 3)Explain when the term "ketose" is used. 4)Explain the difference between a simple carbohydrate and a complex carbohydrate. 5)Which of the following corresponds to the definition of an aldopentose? I. It is a monosaccharide. II. It contains.
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21)Describe how abacteriostatic drug works. 22)Define "bactericidal drug." 23)An important part of a random screen is the recognition of effectiveness in the compounds screened. What term is used to identify the test by which effectiveness is measured? A)assay B)dissolution C)modeling D)combinatorial analysis E)synergism 24)What term is used to describe a.
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31)Define what is meant by "isoelectric point" (pI) and give an example. 32)Which of the following amino acids has its isoelectric point at the lowest pH? A)glutamic acid B)lysine C)valine D)glycine E)methionine 33)What is the pI of arginine? The structure and pKa values are shown below. A)10.76 B)7.90 C)5.61 D)7.33 E)9.67.
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1)Which of the following is incorrect? A)Animals and humans metabolize compounds in the same way. B)Chocolate is metabolized as a toxin in dogs. C)All humans metabolize compounds in the same way. D)A and B E)A and C 2)Which of the following statements is/are true about metabolism? A)reactions that living organisms.
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1)What is a drug? 2)Which of the following common drugs is an antihistamine? A)Claritin B)Norvasc C)Prozac D)Trimox E)none of the above 3)Synthroid is used to treat underactivity of the __________. A)kidneys B)hypothalamus C)liver D)pancreas E)thyroid 4)Explain the difference between a brand name and a generic name for a drug. 5)Which.
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1)Define "lipid." 2)The word "lipid" comes from the Greek lipos, which means __________. 3)Would the addition of HCl to the double bond of oleic acid, CH3(CH2)7CH?CH(CH2)7CO2H, occur with high regioselectivity? Explain. 4)Which of the following statements is not true about fatty acids? A)Fatty acids are carboxylic acids with long hydrocarbon.
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11)What compound is the most widely used analgesic for severe pain? A)Librium B)dextromethorphan C)Ativan D)Benadryl E)morphine 12)Based on the structures of morphine, codeine, and heroin, explain why heroin is the most rapid acting member of the opiate family. 13)Which drug is the most widely used analgesic for severe pain? A)aspirin.
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41)An aqueous solution of glucose behaves as an aldehyde because __________. A)it is hydrolyzed by water to the free aldehyde B)it is a ketone, but is in equilibrium with the aldehyde form C)glucose is actually a cyclic aldehyde D)its cyclic hemiacetal, the predominant form, is in equilibrium with the free.
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31)An optically active D-aldopentose produced an optically active alditol upon treatment with NaBH4. When this aldopentose was subjected to a Ruff degradation, a D-aldotetrose was generated. This aldotetrose gave an optically active aldaric acid upon oxidation with HNO3. Use these data to provide the structure of the starting D-aldopentose. 32)An.
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21)Describe the primary structure of DNA. 22)Which of the following statements explains what nucleic acids are? A)They are acidic in nature. B)They are the carriers of genetic information. C)DNA and RNA are collectively known as nucleic acids. D)Nucleic acids are chains of five-membered ring sugars, each bonded to a heterocyclic.
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61)Consider the two peptides shown below. Which of the following methods would be able to distinguish between these two sequences? Ala-Met-Val-Leu-Gly-Gly-Phe-Glu-Arg-Val and Ala-Val-Gly-Glu-Val-Met-Leu-Gly-Arg-Phe A)one cycle of Edman's reagent B)chymotrypsin digestion C)complete hydrolysis of all peptide bonds D)both A and B E)none of the above 62)What are enzymes? A)saccharides that catalyze chemical reactions  B)nucleic acids.
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  11)What organic compounds are formed when linoleic acid, CH3(CH2)4CH?CHCH2CH?CH(CH2)7CO2H, is ozonolyzed and subsequently treated with H2O2? 12)Which of the following statements best describes the structure of waxes? A)long-chain unsaturated carboxylic acids B)long-chain saturated carboxylic acids C)long-chain esters D)short-chain esters E)long-chain anhydrides 13)Which of the following terms best describes the compound.
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  31)Which of the following statements is not true about phospholipids? A)They are similar to triacylglycerols except that the middle OH group of glycerol reacts with a phosphate rather than with a fatty acid. B)They constitute a major component of cell membranes. C)Phosphatidic acid is a phospholipid. D)The C-2 carbon of.
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51)Six-membered cyclic hemiacetals and five-membered cyclic hemiacetals are called, respectively, __________. A)mannoses and xyloses B)maltoses and arabinoses C)pyranoses and fructoses D)glyoses and fructoses E)none of the above 52)Anomers of D-glucopyranose differ in their stereochemistry at __________. A)C1 B)C2 C)C3 D)C4 E)C5 53)A pyranose with the hydroxyl group on the anomeric.
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31)Show the hydrogen bonding which occurs when adenine and thymine form a base pair. 32)What is the sequence of bases in the strand of DNA that is complementary to that shown below? 5'-T-T-C-A-C-T-G-A-C-3' A)5'-T-T-C-A-C-T-G-A-C-3' B)3'-T-T-C-A-C-T-G-A-C-5' C)5'-A-A-G-T-G-A-C-T-G-3' D)5'-G-T-C-A-G-T-G-A-A-3' E)3'-U-U-C-A-C-U-G-A-C-5' 33)Explain why RNA is easily cleaved and DNA is not. 34)What is meant.
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  41)Which of the following terms best describes the compound below? A)a steroid B)an unsaturated triglycaride C)a soap D)a complex lipid E)a terpene 42)A terpene is believed to have one of the structures below. Based on the isoprene rule, which structure is more likely. Explain your reasoning. 43)Circle the isoprene units.
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  51)Which of the following statements is true for both cholesterol and vitamin A? A)Both are vitamins. B)Both are proteins. C)Both are lipids. D)Both are steroids. E)Both are fatty acids. 52)Which of the following vitamins are lipids? I.vitamin A II.vitamin B1 III.vitamin B2 IV.vitamin B6 V.vitamin B12 VI.vitamin C VII.vitamin D               VIII.vitamin E IX.vitamin H X.vitamin K A)II, III, IV, and.
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21)How many stereoisomers are possible for a 2-ketohexose? A)2 B)4 C)8 D)16 E)32 22)Which of the following statements best describes the difference between amylose and amylopectin? A)Amylose is a branched polysaccharide while amylopectin is a chain polysaccharide. B)Amylose is a straight-chain polysaccharide while amylopectin is a branched polysaccharide. C)Amylose contains.
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1)Where was DNA first isolated? 2)Define a "nucleoside." 3)Define a "nucleotide." 4)Which of the following are known as pyrimidines? A)cytosine and thymine B)adenine and cytosine C)adenine and thymine D)guanine and thymine E)adenine and guanine 5)Which of the following bases distinguish DNA from RNA? A)adenine and cytosine B)guanine and uracil C)thymine.
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51)What is the name of the reagent most often used in the synthesis of peptides to activate the carboxyl group? A)t-butanol B)dicyclohexylcarbodiimide C)di-tert-butyl dicarbonate D)phenylalanine 52)Which of the following structures can polypeptides have? A)primary structure B)secondary structure C)tertiary structure D)quaternary structure E)all of the above 53)Which type of protein, globular.
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71)__________ is commonly used an internal reference in NMR spectroscopy; its signal is assigned δ = 0 in 1H and 13C NMR spectroscopy. 72)Which of the following protons gives an NMR signal with the highest chemical shift value (farthest downfield)? F?CH2CH2CH2CH2CH2?Br 12345  A)1 B)2 C)3 D)4 E)5 73)Which of the following.
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41)Define "translation." 42)Which of the following statements concerning nucleic acids is not correct? A)The enzymes that catalyze DNA synthesis are known as DNA polymerases. B)The growing DNA polymer is synthesized in the 5' to 3' direction. C)RNA strands are synthesized in the 3' to 5' direction. D)In DNA the distance.
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81)What splitting pattern is observed in the proton NMR spectrum for the indicated hydrogens? A)singlet B)doublet C)triplet D)quartet E)septet 82)What splitting pattern is observed in the proton NMR spectrum for the indicated hydrogens? A)singlet B)doublet C)triplet D)quartet E)septet 83)What splitting pattern is observed in the proton NMR spectrum for.
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1)Most biological catalyst are enzymes. 2)What is the name for the reactant in an enzyme-catalyzed reaction? A)solvent B)active site C)cofactor D)substrate E)coenzyme catalysis 3)How do enzymes differ from nonbiological catalysts? A)They have specificity for the substrate. B)They have lower molecular weights than nonbiological catalysts. C)They require higher pressure to be.
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