7 ' 2. 1. There are multiple versions of the exam- You have version A. Mark A for question 1. All of the following compounds are expected to make hydrogen bonding interactions in the cytosol, rather than associating within the plasma membrane, EXCEPT A. cholesterol .Bl Ohospholipid head groups y' glucose 't ,'' '. D. threonine i 1 {xp Which of the following could be expected to DECREASE the fluidity of a cell membrane? A- attaching oligosaccharides to the polar ends of phospholipids B. increasing the % of phospholipids with saturated fatty acids C. increasing the temperature of the environment D. decreasing the length of fatty acid chains on phospholipids E. decreasing the % of phospholipids with saturated fatty acids Which reaction below, if any, represents a catabolic process? A. 6CO2 + 6H2O - C6H12O6 + 69, B. Sucrose - fructose + glucose C. amino acids * protein D. dNTPs * DNA E. None ofthe above Which of the following sequences represents the complementary strand of chromosomal DNA for the seq ue nce S'-AGCTGGCCTA-3'? A. 5'-TCGACCGGAT-3' B. 5'-UAGGCCAGCU-3' C. 5'-ATCCGGTCGA-3' D. 5'-TCGAGGCCAT-3' E. 5'-TAGGCCAGCT-3' 6. The molecular formula for glucose is C5H12O5. What is the molecular formula of a potymer made by covalently linking twelve glucose molecules together by dehydration reactions? 3. 4. 5. I t?" (p 1' A. CnHuqOtz R C72H133051 lc) crrH.,rro^, D CorHrggOor E. CzzHr:aOao it Hr.0 "it-zt+ tl CI Lt, Hrq.l OZz t1- o b0 7. Which of the following statements is FALSE about enzyme-catalyzed reactions? { They must still overcome activation energy, B. The equilibrium of the enzyme-catalyzed reaction favors products, whereas the equilibrium for the same reaction in the absence of the enzyme favors reactants. G: The activation energy is not the same as for the un-catalyzed reaction. - B- The activation energy is lower than that for the un-catalyzed reaction. E, The free energy change is the same for the enzyme-catalyzed reaction as it is for the same reaction in the absence of the enzyme. 8. According to the fluid mosaic model of membrane structure, integral membrane proteins are primarily X. bound to the surface of a lipid bilayer. I positioned in a continuous layer across the entire inner and outer surfaces of the membrane. (C) oriented in the membrane with a fixed inside-outside polarity. D: contained strictly within the hydrophobic interior of the membrane. y'freelydiffusingintothesurroundingsolution. Did you confirm your answer for question 1, the version of the exam? Page 1 of 8 a- I r t- ,/ 9. Transmembrane proteins can have any of the following functions EXCEPT / A. protein-protein interactions. B. intercellular signaling. C^ water channeling. /D.) enzyme synthesis. )f active transport. 10. [hich of the following is NOT a characteristic of microtubules: A ) ffrey associate with myosin motor proteins. B. They allow cilia to beat in an oar-like fashion. C. They are responsible for separating chromosomes during cell division. D. They are composed of globular monomers that polymerize asymmetrically. E. They are involved in vesicle transport. 11. lncubation of human cheek cells in water causes the normally flat cells to assume a round shape. The cause of this phenomenon is A. destruction of the cytoskeleton B. destruction of the cell wall C. increased phospholipid synthesis D. osmotic pressure E. damage to the plasma membrane 12. Actin filaments and microtubules are similar in all of the following EXCEPT X they both form long polymeric structures p1 tney are both components of the cytoskeleton CrAhey are both multi-subunit filaments composed of globular protein subunits O: they are both used for movement of macromolecules E. they both polymerize from centrioles during celldivision in animals 13. Most fat in mice is white fat, but a subset of fat is known as brown fat. Brown fat cells have a much higher concentrationofmitochondriathanwhitefatce]ls.Thesemitochondria@portfrom ATP production-yet still metabolize 4ifitlllGaA. What is most likely the function of brown fat versus white? ,2( to produce high levels of COz that can be used for anabolic reactions '9- brown fat cells should produce more water per acetyl-coA than white fat cells (prevents dehydration) C. to help generate heat D. to regulate pH of the tissue Wto regulate the endomembrane system via feedback inhibition 14. Which of the following statements is TRUE about a chemical reaction whose equilibrium constant (K"o) is greaterthan 10 al25"C? A. The reaction is not spontaneous. B. Substrate concentration will be higher than product concentration at equilibrium C. AG for the reaction is positive D. AG for the reaction is negative E. Whether AG for the reaction is positive or negative cannot be determined from this information 15. The transmembrane regions of a transporter protein are likely'to have amino acids with which type of R- groups exposed to the interior of the plasma membrane? A. polar B. non-polar C. acidic D. basic E. charged 16. A protein component of the ribosome that interacts with RNA would be expected to have which of the following properties? A. lt would have many basic sidechains on its external surface. B. lt would have many acidic sidechains on its external surface. C. lt would be amphipathic. D. lt would be allosterically regulated. E. lt would be regulated by reversible phosphorylation. Page 2 of 8 \ 7', 17. 18. Which of the following intercellular junctions functions to transfer molecules between plant cells? A. desmosomes B. plasmodesmata C. tight junctions D. gap junctions E. intercalated discs The rate of an enzyme-catalyzed reaction is found to be 5 x 10-2 nmol/s. After the addition of 10 pmols of substance Q, the reaction rate is measured at 3 nmol/s. The addition of more substrate does not alter the latter rate. Which of the following is most logically consistent with these data? *i Substance Q is a competitive inhibitor of the enzyme. p". Substance Q is a substrate. /C.) Substance Q is a prosthetic group for the enzyme in this reaction. \ Subslance Q induces a conformational change in the active site by binding elsewhere on the enzyme ,,E. Ihe enzyme has quaternary structure. 19. Which metabolic process is most closely associated with an intracellular membrane? A. substrate-level phosphorylation. B. oxidative phosphorylation. C. glycolysis. D. the citric acid cycle. E. lactate fermentation 20. A substrate lipid is known to bind in the hydrophobic pocket of an enzyme. Which of the following amino acid sidechains would you typically expect to comprise such a binding pocket? A. Sidechain I only B. Sidechain llonly C. Sidechain lll only D. Sidechains I and ll E. Sidechains ll and lll a i #F* ,,' ,, t : . !i # '$,Fts $ }r,., -'i li:= :$Y"E I qf'*r r' R group I CH, t- cl'r" t* 'fIHsc*flt R group ll R group lll 21. What property of the amino acid histidine makes it useful in many enzymatic reactions? A. lt is hydrophobic. Yll has a p( near neutral pH. C. lt can react covalently with substrates in the transition state. Pa lt binds to ATP. E. lt stabilizes protein structure. 22. How are enzyme-substrate complexes stabilized during the transitional phase (transition state) of a chemical reaction? A. Weak chemical forces provide sufficient binding energy to reduce G of the transition state j< ,The enzyme binds irreversibly to the transition state structure E Covalent bond(s) provide the binding energy necessary to increase G of the transition state -P1tne enzyme binds rigidly to the substrate in a "lock-and-key" type interaction E: The enzyme accommodates water molecules that are hydrogen-bonded to the substrate surface 23. What prevents the spontaneous depolymerization of polypeptides into amino acids? A. Digestive enzymes are only active at low pH B. Disulfide bridges C. The high amino acid concentration in healthy cells D. The activation energy of peptide bond hydrolysis E. The negative free energy of peptide bond hydrolysis Page 3 of 8 4 s -ll n' /'\' ''tru. o=L-o, Li.o i i o I }\J {]!l I OH 0'i Nl.rr il i ,I ,r'\m o:iu {u-Al a ivo-l \7 H H ogu P Hoo a 25. Prokaryotes have a proton concentration gradient established across their inner membrane. ln a bacterium growing anaerobically by fermentation of glucose to ethanol, what energy source is used to maintain that from NADH to oxygen from Photosystem lto NADH Which A. of the following molecules would you expect to be a competitive inhibitor of amylase? B. C. E. D. { E "" r tt*'# p*,'g; yu".*,H *" l{ u"l;{_ ";"; o1roi1_r,,-, cogcentration gradient? {, Hign energy electrons tra nsferred E. Uign energy electrons transferred /. Arc produced by chemiosmosis \./ "k N/x \C \*1 \ ) *,"-*/ o, Fo ,Fo HN / '-lN\J'oH il*11 ./z\ -J \ l'\ t"r u \*/ ) -J (-) A GTP produced by succinyl-CoA synthetase tF ) ATP produced by substrate level phosphorylation 26. What is the purpose of establishing a concentration gradient across a biological membrane? A. lt provides the energy for enzymatic reactions B. lt stabilizes the structure of the lipid bilayer C. lt provides a means of doing work D. lt reduces the amount of ATP in the cell E. lt stimulates intercellular communication 27. The drug nocodazole destabilizes microtubules. Actively dividing human intestinalepithelialcells grown in tissue culture can be treated with nocodazole. Which of the following effects would you expect to see fairly immediately in actively dividing human intestinal cells in tissue treated with nocodazole? A. inability to divide properly B. disrupted vesicle transport C. inability to synthesize DNA D. AandC E. AandB _ $|, N$+ "jta li - ^.4* -J * 't r'x gw Y ff 1-"*"_. *rr oo**L"x'*J, q{- {tti I ' '.,n-\ 'J n, \-]d rn! r3* Page 4 of 8 7 28. Animal cells often communicate with their neighbors by transferring small molecules from one cell's cytosol to the cytosol of another cell. This exchange requires which of the following: A. tight junctions B. gap junctions C. nuclear pore complexes D. plasmodesmata E. desmosomes 29. ln the absence of oxygen, the bacterium Geobacter metallireducens can transfer an electron from cytoplasmic NADH to extracellular ferric iron (Fe3*) through the electron transport chain in its ptasma membrane. The free energy of this transfer is used to pump protons into the periplasmic space. This is an example of what form of metabolism? A. anaerobicfermentation B. aerobic oxidation C. aerobicfermentation D. anaerobic ferridation E. anaerobic respiration 30. One reason for the difficulty in estimating the total ATP yield of eukaryotic oxidative phosphorylation is: A. glycolysis produces a variable amount of FADH2 P: .lhe electron transport chain can only oxidize Oz under certain conditions - C. in some cell types, the transporter that shuttles electrons from NADH across the mitochondrial membrane transfers them to FADH2 E f nourhas morb free energy that NADH E itdepends on which type of glucose is broken down 31. For the conversion of acetyl-phosphate to acetate and inorganic phosphate (shown below), a AG" of - 8.5 kcal/mole has been measured: What would ttre AGo be for the reaction shown below, where acetyl-phosphate is serving as the phosphate donor for the synthesis of ATP? Acetyl-phosphate + ADP > Acetate + ATP A. + 7.3 kcal/mole @1 - t.2 kcal/mole Y 73kcallmole D. + 2.5 kcal/mole E. None of the above is correct 32. Choose the correct path of electrons during photosynthesis: kl Water ) Sugars ) Glycolysis ) Calvin cycle ) Electron transport chain fE) Water ) Electron transport chain ) NADPH ) Calvin cycle ) Sugars -G _sugars > NADPH ) Calvin cycle ) Electron transport chain ) Water 'p-NnOeH ) Electron transport chain ) Calvin cycle ) Water ) NADP* ) Sugars E Calvin cycle ) Electron transport chain ) Water ) NADPH ) Sugars 33. You are collecting soil samples from various locations in order to determine which types of bacteria are present using DNA sequencing. ln which of the following locations would you be most likely to find bacteria known to be obligate anaerobes? {Topsotl / Sort from a fertile garden C, Soil from an isolated, undisturbed location @ Sludge from the bottom of a lake j<'Soil thatcontains a lotof organic molecules - s.5 + 1.3 Page 5 of 8 ouf 34. The sodium-potassium pump: Po A. Makes use of a protein pump that could be entirely composed of polar amino acids lL I n B. Pumps sodium ions from the outside to the inside of the cell e1 ,ls an example of facilitated diffusion Operates without any net energy gain or loss Relies on conformational changes brought about by phosphorylation and later, dephosphorylation, of the protein pump 35. You add labeled HzO in the form of H218O to a mixture of isolated chloroplasts. After about 30 seconds you find all of the label has been incorporated and you isolate various molecules as listed. Select the best choice for the expected^labeled products. A. only 'oO2 B. only H2180 c. H2180 and 18o2 D. C6H121806and H2180 E. only C6H121806 36. Which statement below is FALSE? *) (uilrio.t4, HrO f 0z $.o f C)t A. DNA and RNA polymerize in one direction as incoming nucleotides are added to the 3' end B. The DNA double helix is formed by two complementary strands that run antiparallelto each other Q Adenine and guanine have purine nitrogenous bases while cytosine and thymine have pyrimidine bases Q. ) Phosphotriester bonds link the adjacent nucleotides in DNA and RNA E. DNA and RNA synthesis and degradation are catalyzed by specific kinds of enzymes 37. An increase in the amount of cholesterol in an animal celt membrane is expected to have what effect on the cell's function? A. increase the number of membrane proteins anchored to the extracellular matrix B. increase the hydrophilic character of the membrane, leading to enhanced ion transport C. decrease membrane fluidity at low temperature and increase membrane fluidity at high temperatures @ increase membrane fluidity at low temperature and decrease membrahe fluidity at high temperatures E. decrease the amount of active transport the cell can carry out 38. Rurines and pyrimidines are and , respectively t/ two ring, one ring; nitrogenous bases B. polar, non-polar, amino acids C. one ring, two ring, nitrogenous bases D. non-polar, polar, amino acids E. ribose and deoxy ribose sugars 39. When fatty acids are metabolized to produce ATP, they enter the process of cellular respiration at the level of A. succinyl-CoA B. citrate C. glucose @ acetyl-CoA H pyruvate 40. Substrate-level phosphorylation in the Krebs cycle depends directly on the energy of the Q) thioester bond of succinyl-CoA B. oxidative decarboxylation of isocitrate to o-ketoglutarate C. thioester bond of acetyl-CoA D. NAD*-dependent oxidation of malate to oxaloacetate E. FAD-dependent oxidation of succinate to fumarate Page 6 of 8 r (B) 'f'r-* 2. I al 10.5+ GI I () Time 2t E- o.sl t u1 I -t -I+ I t 'tim.: 41. For the enzyme-catalyzed reaction S 1) p, lGc = 2. Which of the following best represents the change in [S] that occurs over time when S is aidded to a solution containing the appropriate enzyme? I z to.: ,;. {) @ fi ll t\ Time (A) 2" ia: ?o t? / /z - al (l rl iE) 42. Which of the following statements about chloroplasts and mitochondria is FALSE? .K goicr. organelles are descended from bacteria. B. Both organelles can synthesize ATP using chemiosmosis. f=Aotn org anel les contai n ribosomes. \ Aotn organelles contain a membrane-bound electron transport system. (E. ) Both organelles use organic molecules as a source of high-energy electrons to pump protons. 43. As the oxygen concentration increases ina C3 plant, A. the rate of photorespiration increases. - B tne rate of NAD+ oxidation increases. .{ tne amount of glyceraldehyde-'3-phosphate that is synthesized increases. D. Only A and B are correct. E. A, B and C are correct. 44. Which of the following statements regarding C-4 plants is TRUE? A. They contain both mesophylland bundle-sheath cells. B. They grow in cooler climates with low amounts of sunlight. C. They use pyruvate kinase for their initial fixation of COz D. They are uncommon in nature. E. They have no Rubisco. Exam continues Page 7 of 8 45. Which of the following statements about chlorophyll is FALSE? A. lt is a photosynthetic pigment. B. lt is green in color. C. Only one form is found in CAM plants. D. lt absorbs light in the blue and red regions of the spectrum. E. lt has sufficient hydrophobicity to associate with the thylakoid membranes. 46. Which of the following is/are TRUE about the movement of cilia and flagella in Eukaryotes? y- Dynein"walks" across a microfi lament. 8 Because of the wavelike motion of successive molecular movements, no energy input is necessary. C. Cross-linking proteins cause cilia and flagella to bend instead of sliding past each other. D. None of the above statements are true. )dnn of the above statements are true. 47. During the Calvin cycle, A. ATP is synthesized by substrate-level phosphorylation SlO, is reduced to glyceraldehyde-3-phosphate by Rubisco C. lysosomes degrade oxidized chlorophyll molecules D- ribulose-bisphosphate reacts with Oz (e) runoPH is oxidized to NADP* \_-/ 48. Which of the following is NOT a difference between photosynthesis and cellular respiration? A Photosynthesis produces 02, respiration produces CO2 p. Photosynthesis consumes CO2; respiration consumes 02 Q.)nf e is produced during photosynthesis but not during respiration pZehotosynthesis is powered'by light energy; respiration is powered by the chemical energy of reduced organic molecules JAne principle electron carrier in respiration is NAD*; the principle electron carrier in photosynthesis is NADp* 49. ln yeast cells living in an oxygen-free environment, A. glucose is produced from CO2 B. ethanol is produced during the citric acid cycle (C) ethanol is produced after glycolysis D. lactate is produced during glycolysis E. lactate is produced during anaerobic respiration 50. ln C4 plants, carbon fixation takes place in the using and then is transferred to the where it enters the Calvin cycle. qA) Mesophyll cells, PEP carboxylase, bundle-sheath cell B. Stomata, PEP carboxylase, mesophyllcell C. Bundle-sheath cell, Rubisco, mesophyll cell D. Mesophyll cells, Rubisco, bundle-sheath cell E. Stomata, Rubisco, bundle-sheath cell 51. Evolution of biological order is consistent with the second law of thermodynamics in that filving systems are closed systems and cannot exchange energy and matter with their surroundings. ($) living systems maintain order by increasing the entropy of their surroundings. C. living systems escape the consequences of the second law of thermodynamics by transforming energy. D. A, B, and C are allcorrect statements. E. B and C are correct. END OF THE EXAM Page 8 of 8 to35lA to36lD lo37lD to38lA lo3el D lo4olA lQ41lC->B lo42lE lo43lA lo44lA lo45lc lQ46lD->C lo47lE lo48lc lo4elc tosolA tollA lQ2l D*>A to3lB to4l B tosl E to6lc IOTI B toBIC loel D lo10lA to11lD lo12l E lo13lc lo14lD lo15l B lo16lA lQlBlC:>D tolel B lo20l D lQ21lE->B to22l A lo23l D lo24lc lo2slE 1026lc lo27l E lo28l B lo2elE lo3olc to31lB lo32l B to33l D As rnentioned on the syllabus we guarantee a score of 90 % or above is some fioJ,ff of an A, a score of 80-89% is some form of a8,70-79% is some form of a C,60-69% is some form of a D. The grades reflect this. There are more Bs than we typically give (in a curved situation). There are two versions of the exam with the same questions and the same answer selections butthe two versions of the exam have the questions and the answers in different orders. Thus you will need to go log on to bSpace for a key for your version of the exam, Version A or Version B. Please be sure to put your name on your exam and to fully bubble in your SID and section numbep for exam 2.