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Each of the following subcellular structures contains DNA EXCEPT A. the nucleus. B. ribosomes. C. chloroplasts. D. mitochondria. - โโB In plant and animal cells, the three-dimensional integrity of the cell is maintained, in part, by an internal network of filaments called A. the cell wall. B. the Golgi apparatus. C. the cytoskeleton. D. the endoplasmic reticulum. - โโC Of the following, which are prokaryotes? A. viruses B. bacteria C. yeast D. plant cells - โโB Gยฐ for the conversion of glycerol- 3 - phosphate to glycerol + Pi is - 2.2 kcal/mole. Thus, you can conclude that A. this reaction will occur spontaneously. B. this reaction may or may not occur spontaneously, depending on the
actual concentrations of reactants and products. C. this reaction will only occur spontaneously if it is coupled to another reaction that has a more favorable Gยฐ. D. this reaction is so strongly favorable that it could be coupled to drive an otherwise unfavorable cell reaction. - โโB In most biochemical reactions, โPV is A. negligible B. positive C. negative D. dependent on โE - โโA According to the Second Law of Thermodymnamics, A. the total entropy change in any reaction that occurs spontaneously must be greater than 0. B. the total entropy change in any reaction that occurs spontaneously must be less than 0. C. the total entropy of the universe remains constant. D. the total entropy of the universe is always decreasing. - โโA Which of the following is true? A. Liquid and solid water have the same number of hydrogen bonds per molecule of water B. Liquid water has more hydrogen bonds per molecule than does solid water C. Solid water has more hydrogen bonds per molecule than does liquid water D. Hydrogen bonding is a major factor in the structure of gaseous water E. None is true - โโC What is the pH of an aqueous solution that has a [OH-] of 3.45 x 10-5 M? A. 3.
E. a and b - โโC A reagent commonly employed to cleave disulfide bonds in proteins is A. 2,4-dinitrofluorobenzene B. urea C. 2-mercaptoethanol D. phenylisothiocyanate E. cyanogen bromide - โโC With respect to a relaxed muscle, which of the following is true? A. the number of actin-myosin cross-bridges is maximized and the muscle is shortened B. the number of actin-myosin cross bridges is maximized and the muscle is stretched C. the number of actin-myosin cross bridges is minimized and the muscle is shortened D. the number of actin-myosin cross bridges is minimized and the muscle is stretched E. none of the above - โโD Which of the following does not describe hemoglobin? A. Hemoglobin is an oxygen transport protein. B. Hemoglobin is an allosteric protein. C. Hemoglobin has quaternary structure. D. Copper ions are important in hemoglobin's ability to bind oxygen. E. Hemoglobin is composed, in part, of an iron containing heme group. - โโD Which of the following would allow you to determine the isoelectric point of a protein? A. protein quaternary structure B. protein solubility as a function of pH C. protein size
D. protein shape E. protein tertiary structure - โโB A mixture of urease (pI = 5.1, mol. wt. 482,700), catalase (pI = 5.6 mol. wt. 247,500), lactoglobin (pI 5.2, mol. wt. 37,100) and hemoglobin (pI 6.9, mol. wt. 64,500) were applied in a pH 6.5 buffer to a DEAE- cellulose chromatography column and eluted with the same buffer. What was their order of elution? A. urease, lactoglobin, catalase, hemoglobin B. hemoglobin, catalase, lactoglobin, urease C. urease, catalase, hemoglobin, lactoglobin D. lactoglobin, hemoglobin, catalase, urease E. cannot be determined from the information given - โโB The Km is: A. The time for half of the substrate to be converted to product. B. The time for all of the substrate to be converted to product. C. The [S] that gives half of the maximum reaction rate. D. The [S] that gives the maximum reaction rate. E. The [P] that is produced when the enzyme is saturated with the substrate. - โโC An holoenzyme is A. a coenzyme B. an enzyme with its cofactor C. an enzyme lacking its cofactor D. an allosteric enzyme E. a cofactor - โโB Some non-serine proteases contain
The use of nucleotides such as GTP in a metabolic reaction is energetically equivalent to the use of ATP. This is because the GDP that is produced is rephosphorylated to GTP at the expense of ATP by which of the following enzymes? A. adenylate kinase B. ATPase C. GTPase D. nucleoside diphosphate kinase E. phosphorylase a - โโD Which of the following intermediates is a substrate for the only membrane-associated enzymatic activity in the TCA cycle? A. citrate B. fumarate C. oxaloacetate D. pyruvate E. succinate - โโE The ultimate acceptor of the electrons removed by oxidative decarboxylation in the TCA cycle is A. NAD+ B. NADP+ C. FAD D. ATP E. O2 - โโE Which of the following is the hydrophobic electron carrier which is mobile within the membrane? A. ubiquinone B. complex II C. cytochrome a D. cytochrome b E. cytochrome c - โโA
Electrons from complex I are transferred directly to which of the following electron transport components? A. complex Ia B. complex II C. complex III D. cytochrome c E. ubiquinone - โโE If an antenna chlorophyll absorbs energy from a photon, which is the desired pathway for de-excitation? A. fluorescence B. resonance energy transfer C. donation of the excited electron D. return to the lower energy level with loss of energy as heat - โโB The electrons transferred in the light reactions of photosynthesis end up in which molecule? A. NADPH B. FADH C. water D. oxygen E. carbon monoxide - โโA Which of the following is true concerning the peptide portion of peptidoglycans? A. contain only amide bonds analogous to those in proteins B. contain ester linkages C. contain amide bonds involving the epsilon amino group of lysine D. contain amide bonds involving the gamma carboxyl group of glutamate E. c and d - โโE
E. all of the above - โโE Dietary fats (triglycerides) are imported into the body by which tissues? A. adipose tissue B. intestine C. liver D. pancreas E. skin - โโB In E. coli the last common intermediate for the synthesis of phosphatidylethanolamine and phosphatidylglygerol is A. diacylglycerol B. CDP-diacylglycerol C. phosphatidylserine D. phosphatidic acid - โโB During the formation of glycocholate, cholic acid, CoASH, and ATP form cholyl-CoA, AMP, and pyrophosphate. What reaction intermediate would you expect in this process? A. cholyl phosphate B. cholyl adenylate C. cholyl pyrophosphate D. cholyl group bound to a protein by a thioester linkage - โโB In animals, HMG-CoA is synthesized A. in the cytosol and mitochondrial matrix B. on the endoplasmic reticulum and plasma membrane C. in the Golgi apparatus primarily D. on the endoplasmic reticulum and outer mitochondrial membrane
E. on the plasma membrane - โโA Although only one amino acid is synthesized by the histidine pathway, the pathway is connected to another pathway responsible for the synthesis of A. pyrimidine nucleotides B. coenzyme A C. flavonoids D. Purine nucleotides E. heme - โโD Which of the following amino acids does not play an important role in the active site of serine proteases? A. Lysine B. Serine C. Histidine D. Aspartate E. None of the above - โโA The protein thioredoxin is involved in which of the following processes? A. The reduction of cysteine residues. B. The phosphorylation of cysteine residues. C. The oxidation of cystine residues. D. The reduction of cystine residues. E. The deamination of cystine residues. - โโD Vitamin B12 contains which of the following metals? A. magnesium
E. 5 - โโD
Which of the following conversions is catalyzed by the enzyme 3-phosphoglycerate kinase? A. glycerate- 2 - phosphate to phosphoenol pyruvate B. glycerate- 3 - phosphate to glycerate- 2 - phosphate C. glycerate-1,3-bisphosphate to glycerate- 3 - phosphate D. glyceraldehyde- 3 - phosphate to dihydroxyacetone phosphate - โโC Lipid components of membranes do not readily move from one side of a bilayer to the other. A. true B. false - โโA Phosphatidylinositol A. only functions as an intermediate in the biosynthesis of phosphatidylinositol-4 phosphate in eukaryotes B. does not occur in the membranes of eukaryotes C. constitutes about 5 % of the phospholipids in prokaryotes D. may be converted to two phosphatidylinositol derivatives that yield cellular second messengers in animal cells - โโD How many molecules of ฮด-aminolevulinate are required to make one molecule of porphyrin? A. 2 B. 4 C. 6 D. 8 E. none of these - โโD The nucleotide, dGTP, consists of A. guanine, ribose, and three phosphoryl groups
B. GMP plus two phosphoryl groups C. guanine, 2-deoxyribose, and three phosphoryl groups D. guanosine, 2-deoxyribose, and three phosphoryl groups - โโC A BLAST search compares a sequence of __________ to a database of known sequences. [Q42] a. Proteins b. Proteins or Amino Acids c. Nucleotides or Amino - acids d. Amino Acids e. Nucleotides - โโC A mixture of urease (pI = 5.1, mol. wt. 482,700), catalase (pI = 5.6, mol. wt. 247,500), lactoglobin (pI 5.2, mol. wt. 37,100) and hemoglobin (pI 6.9, mol. wt. 64,500) were applied in a pH 6.5 buffer to a DEAE-cellulose chromatography column and eluted with the same buffer. What was their order of elution? a. urease, lactoglobin, catalase, hemoglobin b. lactoglobin, hemoglobin, catalase, urease c. hemoglobin, catalase, lactoglobin, urease d. urease, catalase, hemoglobin, lactoglobin e. cannot be determined from the information given - โโC A size extraction column... a. tags larger molecules for separation b slows down smaller molecules, allowing larger ones to flow through more readily c tags smaller molecules for separation d slows down larger molecules, allowing smaller ones to flow through more easily - โโB
Michaelis-Menten kinetics d. Cooperative binding of substrate to an enzyme with four or more subunits e.Binding of an inhibitor competitively to the substrate binding site - โโA An alpha-helical conformation of a globular protein in solution is best determined by which of the following? a. Circular dichroism b. Ultraviolet-visible absorbance spectroscopy c. Electron microscopy d. Analytical ultracentrifugation e. Fluorescence spectroscopy - โโA Conversion of 1 mol of acetyl-CoA to 2 mol of CO2 and CoA via the citric acid cycle results in the net production of: a. 1 mol of oxaloacetate b. 1 mol of FADH c. 1 mol of citrate d. 7 mol of ATP e. 1 mol of NADH - โโB DNA directionality is _____. a. 5' to 3' b. 5' to 4' c. 4' to 5' d. 3' to 2' e. 5' to 2' - โโA DNA with which percent component would denature at the lowest temperature?
a. 15% A b. 30% G c. 40% C d. 40% T - โโD During the gluconeogenic conversion of pyruvate into glucose in the liver, all of the following are involved EXCEPT: a. phosphoenolpyruvate carboxylase b. glucose 6-phosphatase c. pyruvate carboxylase d. phosphoenolpyruvate carboxykinase e. fructose 1,6-bisphosphatase - โโA Each amino acid was subjected to paper electrophoresis in a pH 9.5 buffer, and then the amino acids were visualized by spraying the paper with ninhydrin. Which amino acid is at the point labeled (*) in the figure above? (Refer to the very last page of this document for the picture). a. Histidine b. Tryptophan c. Proline d. Arginine e. Cysteine - โโD Electrons from complex I are transferred directly to which of the following electron transport components? a. Cytochrome c b. Complex III c. Ubiquinone d. Complex Ia
d. Keq > 1 e. Keq = 0 - โโC For a given reaction, if โณGยฐ is less than zero, then: a. Keq = 0 b. Keq < 0 c. 0 < Keq < 1 d. Keq = 1 e. Keq > 1 - โโE Given five unlabeled bottles, each bottle containing one of the following amino acids: arginine, histidine, cysteine, proline, and tryptophan. What method would be best to determine which bottle contained the tryptophan? a. Gel filtration b. Optical rotation c. Electrophoresis d. Ultraviolet spectroscopy e. Analytical ultracentrifugation - โโD Gยฐ for the conversion of glycerol- 3 - phosphate to glycerol + Pi is - 2.2 kcal/mole. Thus, you can conclude that... a. this reaction may or may not occur spontaneously, depending on the actual concentrations of reactants and products. b. this reaction is so strongly favorable that it could be coupled to drive an otherwise unfavorable cell reaction. c. this reaction will occur spontaneously. d. this reaction will only occur spontaneously if it is coupled to another reaction that has a more favorable Gยฐ. - โโA
If the DNA of E. coli is about 25% G and C and M. tuberculosis DNA is about 70% G and C, which would be more likely to denature at a lower temperature? side note: (remember, A:T only has 2 hydrogen bonds, and G:C has three hydrogen bonds. Amount of energy required corresponds to this) a. It is not possible to determine with the given information. b. M. tuburculosis c. Both would denature at about the same rates. d. E. coli - โโD In a Lineweaver-Burk plot, the x-axis represents ________, and the y-axis represents ________. a. inverse of substrate concentration, negative inverse of maximum velocity b. inverse of substrate concentration, inverse of maximum velocity c. inverse of initial velocity, inverse of substrate concentration d. inverse of maximum velocity, inverse of substrate concentration e. inverse of substrate concentration, inverse of initial velocity. - โโE In a Michaelis-Menten plot, the x-axis represents ________, and the y-axis represents ________. a. maximum velocity, substrate concentration b. initial velocity, substrate concentration c. substrate concentration, initial velocity d. substrate concentration, maximum velocity e. substrate concentration, negative maximum velocity - โโC In comparing fatty acid biosynthesis with ฮฒ oxidation of fatty acids, which of the following statements is incorrect?
