Test 1 Spring 2000

Test 1 Spring 2000 - Bil 255 Spring 2000 Charles Mallery...

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Unformatted text preview: Bil 255 Spring 2000 Charles Mallery FORM 0 Test # 1 February 21, 2000 Directions: From among the choices for each question, PICK the BEST choice . 1. The isolation of a cell free extract that is able to ferment [convert sugar into alcohol] was first accomplished by? a) Enrico Glycolysis b) Kerry B. Mullis c) Eduard Buchner d) Emil Fischer e) choose this answer if none of these is correct 2. The first determination of the molecular structure of a protein (insulin) was accomplished by? a) Theodor Schwann b) Erwin Chargaff c) Alfred Hershey & Martha Chase d) Fred Sanger e) choose this answer if none of these is correct 3. The 20th century has been characterized by a ‘research philosophy’ of investigation that is best called? a) vitalism b) reductionism c) holistic d) theoretical e) none of these is correct 4. “Life as we know it on the planet Earth may have begun in the Universe via the organic seeding and water dumping by comets”. This statement is a tenet of which of the following ‘Origin of Life” theories? a) panspermia b) Special Creation c) chemical evolution d) relativity e) choose this answer if none of these is correct 5. A molecular complex, which has the ability to make a copy of itself and direct other molecules to replicate themselves, is best referred to as? a) tierrians b) abiotic catalysts c) replicases d) biomorphs e) choose this answer if none of these is correct 6. The halophilic bacteria that live in places like the Great Salt Lake of Utah and The Dead Sea are classified as? a) eubacteria b) metaphytian cells c) true nuclear containing cells d) archaebacteria e) choose this answer if none of these is correct 7. The molecule(s) occurring in the greatest proportion (by % of total weight) in a living bacterial cell is (are)? a) inorganic ions b) sugars & precursors c) water d) macromolecules e) choose this answer if none of these is correct 8. The carbonyl [ -C=O ] chemical functional group is best defines which of the following molecules? a) sulfhydryls b) aldehydes and ketones c) amines d) sterols e) choose this answer if none of these is correct 9. The molecule depicted in the figure to the right is made of a ? a) fatty acids b) sugars c) amino acids d) nucleotides e) choose this answer if none of these is correct 10. The type of bond depicted in the shaded area is a? a) glycosidic bond b) hydrogen bond c) peptide bond d) ionic bond e) choose this answer if none of these is correct 11. Pure water is neutral and contains how many [H+] in moles/liter? -14 -7 -0 7 a) 10 b) 10 c) 10 d) 10 e) choose this answer if none of these is correct 12. The substrate level phosphorylation step that occurs in the Krebs cycle generates _____ directly? a) NADH b) GTP c) ATP d) glucose-6-P e) none of these is correct Page 2 Form 0 Bil255s00 – Test #1 13. Which of the following metabolic processes or components in the breakdown of the cereal and milk you had for breakfast today will directly generate the most ATP? a) glycolysis b) citric acid cycle c) pyruvate dehydrogenase complex d) ATP synthase e) choose this answer if none of the above is correct 14. Per mole of glucose, which would release the greater amount of free energy: the gradual oxidation of glucose during cellular respiration or the rapid combustion of glucose by burning. a) more free energy is released by cell respiration b) more energy is released by the burning of glucose c) exactly the same amount of overall free energy, per mole, is released by both methods d) choose this answer if none of the above is correct 15. The final product of glycolysis is pyruvate, while the final product of anaerobic respiration is? a) alcohol b) citrate c) DHAP d) lactic acid e) none of these 16. The type of molecular force or chemical bond [hash marks] depicted in the drawing to the right is most likely ? a) ionic bonds b) disulfide bonds c) hydrogen bonds d) peptide bonds e) choose this answer if none of these is correct 17. In a tensegrity view of cell structure, the microtubules of the cytoskeleton might be the compression struts and the microfilaments and intermediate filaments might be the tensile wires analogous to Kenneth Snelson's multi-story towers and large scale amorphous exoskeletons of wire and steel. a) true b) false 18. The cellular reaction taking place in the diagram to the right is classified as? a) a redox reaction b) hydrolysis c) condensation d) decarboxylation e) choose this answer if none of these is correct 19. If the ∆Go’ for the reaction in Q18 is +7.3 Kcal/mole, then the addition of the enzyme sucrase will make this reaction form sucrose? a) true b) false 20. During the oxidation of glucose in cells, CO2 may be produced in which of the following? a) conversion of PYR to acetyl-coA b) alcoholic fermentation c) Krebs cycle d) citric acid cycle e) choose this answer if all of the above are correct The next 5 questions refer to the following answer choices: A) mitochondrial membrane B) mitochondrial matrix D) peri-mitochondrial space E) nucleus 21. Where does glycolysis occur in Eukaryotic cells? a) A b) B c) C d) D e) E 22. Where does the electron transfer chain reside in Eukaryotic cells? a) A b) B c) C d) D e) E C) cytosol Page 3 Form 0 23. Where does substrate level phosphorylation occur? a) A & B b) B & C c) C & D d) D & E Bil255s00 – Test #1 e) none of these is a correct choice 24. Where does the enzyme complex, pyruvate dehydrogenase occur? a) A b) B c) C d) D e) E 25. During electron transfer in Eukaryotic cells, hydrogen ions would accumulate in? a) A b) B c) C d) D e) E 26. In the most common shape found in globular proteins in cells, non-polar, hydrophobic amino acids tend to be found in the interior and hydrophilic, polar amino acids are at the exterior? a) true b) false 27. Peptide bonds are the only covalent bonds that can link together two amino acids? a) true b) false 28. From what you can recall about the enzyme lysozyme, which catalyzes the hydrolysis of linear polysaccharide, it would be able to cleave a disaccharide as maltose? a) true b) false 29. You might use an antibody or substrate molecule, bound to an inert matrix in column chromatography, to purify a specific protein from a mixture of proteins by the technique of? a) ion-exchange chromatography b) affinity chromatography c) velocity sedimentation d) density gradient centrifugation e) none of these is correct 30. The centrifugation technique used to separate sub-cellular components or proteins at different speeds through a shallow sucrose gradient and according to their size is referred to as? a) differential centrifugation b) equilibrium sedimentation c) velocity sedimentation d) angular rotation e) none of these is a correct answer 31. If a researcher wanted to separate a partially purified protein from others by its molecular weight, the best choice of procedure might be? a) SDS-PAGE (sodium-dodecyl-sulfate polyacrylamide gel electrophoresis) b) column chromatography c) isolelectric focusing d) NMR spectroscopy e) none of these 32. Enzymes bind their _____ at the ______? a) products : N-terminal ends b) substrates : active site c) regulator : allosteric site d) both b and c are correct e) choose this answer if all of the above are correct 33. Pyruvate transport from the cytosol into the mitochondria occurs via a co-transport mechanism in which _______ is transported along with PYR? a) NADH b) ADP c) glucose d) H+ e) none of these 34. An increase in Ca+2 concentration might be expected _______ the rate Krebs cycle reactions? a) decrease b) totally inhibit c) increase d) have on effect at all 35. Which of the following molecules is not a direct product made in fatty acid oxidation? a) NADH b) FADH2 c) acetyl-coA d) CO2 e) choose this answer if all of the above are made in fatty acid oxidation 36. Carbon atom for carbon atom more total energy equivalents (as ATP equivalents) can be made by the oxidation of glucose in aerobic cellular respiration (including glycolysis, KC & ETC) than by the complete oxidations of the acetyl coA’s made from fatty acid oxidation of a 6 carbon fatty acid? a) true b) false Page 4 Form 0 Bil255s00 – Test #1 37. A 0.1 ml aliquot (i.e., a small fraction) of a 25.0 ml homogenate (total volume) of a chicken’s whole liver (weighing 10.0 gm) is shown to have an Absorbance of 0.50. Using the BSA (bovine serum albumin) Standard Protein curve below, how much protein is present in the total homogenate? a) 4 mg b) 100 mg BSA c) 1,000 mg d) 12.5 mg 1.2 e) not determinable from this data 1 Absorbance 38. If that same 0.1 ml aliquot of liver homogenate converts 48 µmoles of glucose to glucose-6-P in 8 minutes then the total number of units of enzyme activity present in the chicken’s liver is? a) 384 units b) 6 units c) 1,500 units d) 38.4 units e) none of these is correct 0.8 0.6 0.4 0.2 39. The specific activity of the enzyme from these chicken livers which converts glucose to glucose-6-P is? a) 1.5 U/mg b) 38.4 U/mg c) 12.5 U/mg d) 375 U/mg e) none of these 0 0 1 2 4 6 8 10 mG BSA Protein 40. Succinate dehydrogenase is an enzyme that oxidizes succinate to fumerate. Malonic acid is a competitive inhibitor of the enzyme SDH. A mitochondrial sample of SDH gave the following data. By careful examination of the data determine the probable the Km for SDH is? rate of NATIVE reaction concentration of succinate 2.0 units 1.0 µmoles of starch 7.5 units 4.0 µmoles of starch 13.0 units 9.1 µmoles of starch 15.05 units 15.2 µmoles of starch 14.95 units 25.1 µmoles of starch 15.0 units 40.2 µmoles of starch a) 1.0 µmole b) 2.0 µmoles c) 4.0 µ moles d) 40.2 µmoles e) not determinable from the data that is given 41. From the data on SDH above, what would be the Vmax at high substrate concentrations for this enzyme in the presence of the competitive inhibitor malonic acid? a) 15 units b) 2 units c) 7.5 units d) 40.2 µmoles e) not determinable from the data that is given 42. The enzyme ribonuclease is depicted in the drawing to the right. The spiral region labeled (A) commonly represents ? a) alpha-helix regions b) beta sheet regions c) allosteric sites d) disulfide bonds e) none of these is a correct choice 43. The fattened ribbon regions, depicted by the label (B) are? a) alpha-helix regions b) beta sheet regions c) allosteric sites d) disulfide bonds e) none of these is a correct choice Page 5 Form 0 Bil255s00 – Test #1 The next 4 questions relate to the figure to the below. You have isolated two kinase enzymes (A and B) and are studying them. Enzyme A converts glucose + ATP <---> glucose-6P & enzyme B converts glucose + ATP <---> glucose-1-P. You first measure the rate of reaction glucose + ATP <---> glucose-6P in the presence of a constant amount of enzyme A and varying amounts of substrate glucose . You then measure the rate of the reaction glucose + ATP <---> glucose-1-P in the presence of a constant amount of enzyme B and varying amounts of glucose . The number of enzyme A and B molecules per ml are exactly the same in the two Experiments. You plot the results (see figure to the below). 10 units activity 8 6 Enz A Enz B 4 2 0 0.001 0.25 0.3 0.4 1 2 4 8 12 24 25 umole glucose 44. The Vmax for enzyme B is closest to? a) 12.5 umole glucose b) 10 units c) 6 units d) 2.5 µmoles 45. The Km for enzyme A is closest to which of the following? a) 2 u:moles glu b) 2.0 units c) 24 µmoles glu e) none of these d) 0.3 µmoles glu 46. Which enzyme, A or B, has the greater affinity for its own substrate? a) A b) B c) neither, each has the same affinity e) none of these d) none of these is correct 47. If enzyme A were subjected to non-competitive inhibition by the drug insulineride, would expect the Vmax to: a) remain the same b) increase c) decrease d) none of these 48. If a hypothetical redox couple, Miamiase, has a standard redox potential of –0.28 volts and the redox couple H2O/O2 has a redox potential of +.82 volts. Electrons will flow normally from water toward Miamiase. a) true b) false 49. Thermogenin is an ETC uncoupler protein, which generates heat, as it uncouples the pH gradient in brown fat in hibernating animals, by shuttling protons through itself instead of through ATP synthase. a) true b) false 50. The mitochondrial ATP synthase enzyme can function either to synthesize ATP or pump protons against their electrochemical gradient by hydrolyzing ATP to ADP + P. a) true b) false Page 6 Form 0 Bil255s00 – Test #1 Extra Credit: 51. You are studying a microorganism in which a "male" turns blue in the presence of a "female" microorganism. The male becomes blue because a protein "F", secreted by the female binds to and activates a protein "B" on the male's membrane surfaces, which is responsible for the visible color change. You isolate a new strain of the microorganism, but it produces a mutant form of the protein "F". This new strain of the microorganism behaves normally at temperatures below 370C, but at higher temperatures, it can not turn blue. Which of the following explanations is likely to be a correct interpretation of the observations. a) The mutant protein makes fewer hydrogen bonds to protein B b) the mutant protein forms a covalent bond with protein B c) the mutant protein is likely to be unfolded at temperatures higher than 370C d) the mutant protein is likely to be unfolded at temperatures lower than 370C e) choose this answer if none of the above is a likely explanation of the observations 52. When purified samples of a protein - Pearsonase - and of a mutant version of Pearsonase labeled Mahoneyase - are both washed through the same gel-filtration column chromatography, the mutant protein - Mahoneyase - runs through the column much slower than the normal protein - Pearsonase. Which of the following changes in the structure of the mutant protein are most likely to explain this observation? a) the formation of a new binding site on the mutant protein's surface through which it forms a dimer b) a change which results in the mutant protein acquiring an overall positive rather than negative charge c) a change that results in the mutant protein being smaller and more compact than the normal protein d) a change in the mutant protein having a slightly different shape than the normal protein e) choose this answer if none of the above is likely to explain the observation 53. In "Medical Terminology" for the Layman which of the following is correct. a) VARICOSE VEINS are veins, which are very close together b) FESTER is a member of the Addams family CAT SCAN is a search pattern for a kitty c) NITRATE is cheaper than day rate d) COLIC is a sheep dog e) none of the above is correct - you must PICK this choice to receive credit. ...
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This document was uploaded on 10/27/2011 for the course BIL 255 at University of Miami.

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