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Exam Name___________________________________ MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) When biologists wish to study the internal ultrastructure of cells, they can achieve the finest resolution by using 1) _______ A) a transmission electronic microscope. B) a phase-contrast light microscope. C) a super-resolution fluorescence microscope. D) a confocal fluorescence microscope. E) a scanning electron microscope. 2) A primary objective of cell fractionation is to 2) _______ A) sort cells based on their size and weight. B) view the structure of cell membranes. C) separate the major organelles so that their particular functions can be determined. D) determine the size of various organelles. E) separate lipid-soluble from water-soluble molecules. 3) What technique would be most appropriate to use to observe the movements of condensed chromosomes during cell division? 3) _______ A) confocal fluorescence microscopy B) scanning electron microscopy C) light microscopy D) transmission electron microscopy E) super-resolution fluorescence microscopy 4) All of the following are part of a prokaryotic cell except A) an endoplasmic reticulum. B) DNA. C) ribosomes. D) a cell wall. E) a plasma membrane. 4) _______ 5) Which of the following statements concerning bacteria and archaea cells is correct? A) DNA is present in the mitochondria of both bacteria and archaea cells. B) Archaea cells contain small membrane-enclosed organelles; bacteria do not. C) DNA is present in both archaea cells and bacteria cells. D) Archaea cells contain a membrane-bound nucleus; bacteria do not. 6) Which organelle or structure is absent in plant cells? A) centrosomes B) microtubules C) mitochondria D) peroxisomes E) Golgi vesicles 5) _______ 6) _______ 7) Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? A) nucleic acids B) cellulose C) glycogen D) proteins E) lipids 8) A cell with a predominance of free ribosomes is most likely 8) _______ A) digesting large food particles. B) producing primarily proteins for secretion. C) producing primarily cytoplasmic proteins. D) constructing an extensive cell wall or extracellular matrix. E) enlarging its vacuole. 7) _______ 9) Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids? 9) _______ A) contractile vacuole B) lysosome C) ribosome D) mitochondrion E) smooth endoplasmic reticulum 10) Which structure is the site of the synthesis of proteins that may be exported from the cell? A) lysosomes B) free cytoplasmic ribosomes C) plasmodesmata D) Golgi vesicles E) rough ER 10) ______ 11) The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells? 11) ______ A) rough ER B) smooth ER C) transport vesicles D) Golgi apparatus E) nuclear envelope 12) Which of the following produces and modifies polysaccharides that will be secreted? 12) ______ A) mitochondrion B) lysosome C) peroxisome D) Golgi apparatus E) vacuole 13) Which organelle often takes up much of the volume of a plant cell? 13) ______ A) lysosome B) peroxisome C) mitochondrion D) Golgi apparatus E) vacuole 14) Which organelle is the primary site of ATP synthesis in eukaryotic cells? A) lysosome B) peroxisome C) vacuole D) mitochondrion E) Golgi apparatus 15) Thylakoids, DNA, and ribosomes are all components found in A) mitochondria. B) nuclei. C) lysosomes. D) chloroplasts. E) vacuoles. 14) ______ 15) ______ 16) In a plant cell, DNA may be found 16) ______ A) in the nucleus, mitochondria, and chloroplasts. B) only in the nucleus and mitochondria. C) only in the nucleus. D) in the nucleus, mitochondria, chloroplasts, and peroxisomes. E) only in the nucleus and chloroplasts. 17) Which type of organelle is found in plant cells but not in animal cells? A) mitochondria 17) ______ B) plastids C) nuclei D) ribosomes E) none of these 18) Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? 18) ______ A) sites of energy production in cellular respiration B) ribosomes C) membrane proteins D) cellulose fibers in the cell wall E) cytoskeletal structures 19) Movement of vesicles within the cell depends on what cellular structures? A) actin filaments and ribosomes B) actin filaments and microtubules C) actin filaments and motor proteins D) centrioles and motor proteins E) microtubules and motor proteins 19) ______ 20) The smallest cell structure that would most likely be visible with a standard (not super-resolution) research-grade light microscope is 20) ______ A) a microfilament. B) a mitochondrion. C) a ribosome. D) a nuclear pore. E) a microtubule. 21) Cells require which of the following to form cilia or flagella? A) intermediate filaments B) actin C) laminin D) centrosomes E) secretory vesicles 21) ______ 22) All of the following serve an important role in determining or maintaining the structure of plant cells. Which of the following are distinct from the others in their composition? 22) ______ A) microfilaments B) nuclear lamina C) intermediate filaments D) microtubules E) plant cell walls 23) Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells? A) tight junctions B) peroxisomes C) desmosomes D) extracellular matrix E) gap junctions 24) Signals between the ECM and the cytoskeleton may be transmitted by A) collagen. B) proteoglycans. C) middle lamella. D) fibronectin. E) integrins. 24) ______ 25) ECM proteins are made by ribosomes in which part of a eukaryotic cell? A) cytoplasm 25) ______ 23) ______ B) rough ER C) nuclear envelope D) Golgi apparatus E) mitochondria 26) Which structure is not part of the endomembrane system? 26) ______ A) chloroplast B) Golgi apparatus C) nuclear envelope D) ER E) plasma membrane 27) Which structure is common to plant and animal cells? A) wall made of cellulose B) centriole C) central vacuole D) chloroplast E) mitochondrion 27) ______ 28) Which of the following is present in a prokaryotic cell? A) mitochondrion B) ribosome C) ER D) chloroplast E) nuclear envelope 28) ______ 29) What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell? 29) ______ A) nucleus →ER →Golgi B) ER →Golgi →vesicles that fuse with plasma membrane C) Golgi →ER →lysosome D) ER →lysosomes →vesicles that fuse with plasma membrane E) ER → Golgi → nucleus 30) Who was/were the first to propose that cell membranes are phospholipid bilayers? A) E. Gorter and F. Grendel B) I. Langmuir C) H. Davson and J. Danielli D) C. Overton E) S. Singer and G. Nicolson 30) ______ 31) Singer and Nicolson's fluid mosaic model of the membrane proposed that 31) ______ A) membranes are a phospholipid bilayer between two layers of hydrophilic proteins. B) membranes are a phospholipid bilayer. C) membranes are a single layer of phospholipids and proteins. D) membranes consist of a mosaic of polysaccharides and proteins. E) membranes consist of protein molecules embedded in a fluid bilayer of phospholipids. 32) Which of the following types of molecules are the major structural components of the cell membrane? 32) ______ A) nucleic acids and proteins B) phospholipids and cellulose C) phospholipids and proteins D) glycoproteins and cholesterol E) proteins and cellulose 33) The presence of cholesterol in the plasma membranes of some animals 33) ______ A) enables the animal to add hydrogen atoms to unsaturated phospholipids. B) enables the membrane to stay fluid more easily when cell temperature drops. C) makes the animal more susceptible to circulatory disorders. D) enables the animal to remove hydrogen atoms from saturated phospholipids. E) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell. 34) According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids? 34) ______ A) They frequently flip-flop from one side of the membrane to the other. B) They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane. C) They have hydrophilic tails in the interior of the membrane. D) They can move laterally along the plane of the membrane. E) They are free to depart from the membrane and dissolve in the surrounding solution. 35) In order for a protein to be an integral membrane protein it would have to be 35) ______ A) hydrophobic. B) amphipathic, with at least one hydrophobic region. C) completely covered with phospholipids. D) hydrophilic. E) exposed on only one surface of the membrane. 36) When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are 36) ______ A) carbohydrates. B) cholesterol molecules. C) integral proteins. D) phospholipids. E) peripheral proteins. 37) Which of the following is true of integral membrane proteins? A) They are loosely bound to the surface of the bilayer. B) They are usually transmembrane proteins. C) They serve only a structural role in membranes. D) They are not mobile within the bilayer. E) They lack tertiary structure. 37) ______ 38) The primary function of polysaccharides attached to the glycoproteins and glycolipids of animal cell membranes is ______ A) to mediate cell-to-cell recognition. B) to facilitate diffusion of molecules down their concentration gradients. C) to maintain the integrity of a fluid mosaic membrane. D) to maintain membrane fluidity at low temperatures. E) to actively transport molecules against their concentration gradients. 39) A protein that spans the phospholipid bilayer one or more times is 39) ______ A) a glycoprotein. B) a peripheral protein. C) an integrin. D) an integral protein. E) a transmembrane protein. 40) Which of these are not embedded in the hydrophobic portion of the lipid bilayer at all? A) transmembrane proteins B) integrins C) integral proteins D) glycoproteins E) peripheral proteins 41) Why are lipids and proteins free to move laterally in membranes? 41) ______ A) Molecules such as cellulose can pull them in various directions. B) The interior of the membrane is filled with liquid water. C) Lipids and proteins repulse each other in the membrane. D) Hydrophilic portions of the lipids are in the interior of the membrane. E) There are only weak hydrophobic interactions in the interior of the membrane. 40) ______ 38) 42) What kinds of molecules pass through a cell membrane most easily? A) ionic B) large polar C) small and hydrophobic D) monosaccharides such as glucose E) large and hydrophobic 42) ______ 43) Which of the following is a characteristic feature of a carrier protein in a plasma membrane? A) It requires the expenditure of cellular energy to function. B) It exhibits a specificity for a particular type of molecule. C) It has few, if any, hydrophobic amino acids. D) It works against diffusion. E) It is a peripheral membrane protein. 43) ______ 44) Nitrous oxide gas molecules diffusing across a cell's plasma membrane is an example of A) cotransport. B) facilitated diffusion. C) osmosis. D) diffusion across the lipid bilayer. E) active transport. 44) ______ 45) Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? 45) ______ A) an amino acid B) glucose C) K+ D) CO2 E) starch 46) Which of the following statements is correct about diffusion? 46) ______ A) It is very rapid over long distances. B) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. C) It requires an expenditure of energy by the cell. D) It requires integral proteins in the cell membrane. E) It is an active process in which molecules move from a region of lower concentration to one of higher concentration. 47) Water passes quickly through cell membranes because A) it moves through aquaporins in the membrane. B) the bilayer is hydrophilic. C) water movement is tied to ATP hydrolysis. D) it is a small, polar, charged molecule. E) it moves through hydrophobic channels. 47) ______ 48) Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? ______ 48) A) The animal cell is in a hypotonic solution, and the plant cell is in an isotonic solution. B) The animal cell is in an isotonic solution, and the plant cell is in a hypertonic solution. C) The animal cell is in a hypertonic solution, and the plant cell is in an isotonic solution. D) The animal cell is in a hypertonic solution, and the plant cell is in a hypotonic solution. E) The animal cell is in an isotonic solution, and the plant cell is in a hypotonic solution. 49) In which of the following would there be the greatest need for osmoregulation? A) cells of a tidepool animal such as an anemone B) a red blood cell surrounded by plasma C) a lymphocyte before it has been taken back into lymph fluid D) a plant being grown hydroponically (in a watery mixture of designated nutrients) E) an animal connective tissue cell bathed in isotonic body fluid 49) ______ 50) When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur? 50) ______ A) The cell will become flaccid. B) The cell will become turgid. C) The cell membrane will lyse. D) Plasmolysis will shrink the interior. E) The cell will burst. 51) The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane–more acidic outside the cell than inside the cell. Phosphate transport is an example of 51) ______ A) cotransport. B) facilitated diffusion. C) osmosis. D) active transport. E) passive diffusion. 52) What is the voltage across a membrane called? A) chemical gradient B) electrochemical gradient C) water potential D) osmotic potential E) membrane potential 52) ______ 53) The sodium-potassium pump is called an electrogenic pump because it 53) ______ A) is used to drive the transport of other molecules against a concentration gradient. B) pumps equal quantities of Na+ and K+ across the membrane. C) pumps hydrogen ions out of the cell. D) contributes to the membrane potential. E) ionizes sodium and potassium atoms. 54) The movement of potassium into an animal cell requires A) high cellular concentrations of potassium. B) an energy source such as ATP. C) low cellular concentrations of sodium. D) a potassium channel protein. E) a cotransport protein. 54) ______ 55) Ions diffuse across membranes through specific ion channels A) down their electrochemical gradients. B) down their chemical gradients. C) down the osmotic potential gradients. D) down their concentration gradients. E) down the electrical gradients. 55) ______ 56) Which of the following would increase the electrochemical potential across a membrane? A) a sucrose-proton cotransporter B) a proton pump C) a chloride channel D) a potassium channel E) both a proton pump and a potassium channel 56) ______ 57) The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on? 57) ______ A) It doesn't matter, because the pump is not active in the ER. B) It will be on the side facing the interior of the ER. C) It will be on the cytoplasmic side of the ER. D) It could be facing in either direction because proteins are properly reoriented in the Golgi apparatus. 58) An organism with a cell wall would most likely be unable to take in materials through58) ______ A) osmosis. B) phagocytosis. C) diffusion. D) active transport. E) facilitated diffusion. 59) White blood cells engulf bacteria through what process? A) phagocytosis B) receptor-mediated exocytosis C) exocytosis D) pinocytosis E) osmosis 59) ______ 60) The difference between pinocytosis and receptor-mediated endocytosis is that 60) ______ A) pinocytosis requires cellular energy, but receptor-mediated endocytosis does not. B) pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the plasma membrane surface area. C) pinocytosis brings only water molecules into the cell, but receptor-mediated endocytosis brings in other molecules as well. D) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity. E) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot. 61) In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? 61) ______ A) on the outer surface of the nucleus B) on the inside surface of the cell membrane C) on the outside of vesicles D) on the ER E) on the inside surface of the vesicle 62) A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in 62) ______ A) peroxisomes. B) lysosomes. C) vacuoles. D) secretory vesicles. E) Golgi vesicles. 63) According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly A) embedded in a lipid bilayer. B) free to depart from the fluid membrane and dissolve in the surrounding solution. C) spread in a continuous layer over the inner and outer surfaces of the membrane. D) confined to the hydrophobic interior of the membrane. E) randomly oriented in the membrane, with no fixed inside-outside polarity. 64) Which of the following processes includes all others? A) passive transport B) diffusion of a solute across a membrane C) osmosis D) facilitated diffusion E) transport of an ion down its electrochemical gradient 63) ______ 64) ______ 65) Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? A) metabolism B) dehydration C) anabolism D) catabolism E) catalysis 65) ______ 66) Which of the following is (are) true for anabolic pathways? 66) ______ A) They consume energy to build up polymers from monomers. B) They are usually highly spontaneous chemical reactions. C) They consume energy to decrease the entropy of the organism and its environment. D) They do not depend on enzymes. E) They release energy as they degrade polymers to monomers. 67) Which of the following is a statement of the first law of thermodynamics? 67) ______ A) Kinetic energy is stored energy that results from the specific arrangement of matter. B) Energy cannot be created or destroyed. C) The entropy of the universe is constant. D) Energy cannot be transferred or transformed. E) The entropy of the universe is decreasing. 68) For living organisms, which of the following is an important consequence of the first law of thermodynamics? 68) ______ A) The energy content of an organism is constant. B) The entropy of an organism decreases with time as the organism grows in complexity. C) Life does not obey the first law of thermodynamics. D) Organisms grow by converting energy into organic matter. E) The organism ultimately must obtain all of the necessary energy for life from its environment. 69) Whenever energy is transformed, there is always an increase in the 69) ______ A) entropy of the system. B) free energy of the system. C) enthalpy of the universe. D) free energy of the universe. E) entropy of the universe. 70) Which of the following statements is a logical consequence of the second law of thermodynamics? 70) ______ A) If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. B) Every chemical reaction must increase the total entropy of the universe. C) Energy can be transferred or transformed, but it cannot be created or destroyed. D) If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. E) Every energy transfer requires activation energy from the environment. 71) Which of the following types of reactions would decrease the entropy within a cell? 71) ______ A) anabolic reactions B) hydrolysis C) respiration D) catabolic reactions E) digestion 72) Which of the following is an example of potential rather than kinetic energy? A) light flashes emitted by a firefly B) the flight of an insect foraging for food C) water rushing over Niagara Falls D) the muscle contractions of a person mowing grass E) a molecule of glucose 73) Which of the following is the smallest closed system? A) an organism B) Earth C) the universe D) an ecosystem E) a cell 73) ______ 74) A system at chemical equilibrium 74) ______ A) consumes energy at a steady rate. B) releases energy at a steady rate. C) can do no work. D) consumes or releases energy, depending on whether it is exergonic or endergonic. 72) ______ E) has zero kinetic energy. 75) Which of the following is true for all exergonic reactions? 75) ______ A) The products have more total energy than the reactants. B) The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants. C) A net input of energy from the surroundings is required for the reactions to proceed. D) The reaction proceeds with a net release of free energy. E) The reactions are rapid. 76) A chemical reaction that has a positive ∆G is correctly described as 76) ______ A) endergonic. B) spontaneous. C) enthalpic. D) endothermic. E) exothermic. 77) Which of the following best describes enthalpy (H)? A) the total kinetic energy of a system B) the system's entropy C) the cell's energy equilibrium D) the heat content of a chemical system E) the condition of a cell that is not able to react 77) ______ 78) Why is ATP an important molecule in metabolism? 78) ______ A) Its hydrolysis provides an input of free energy for exergonic reactions. B) Its terminal phosphate bond has higher energy than the other two. C) It is one of the four building blocks for DNA synthesis. D) It provides energy coupling between exergonic and endergonic reactions. E) Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy. 79) Which of the following is most similar in structure to ATP? A) a DNA nucleotide B) an amino acid with three phosphate groups attached C) a phospholipid D) a pentose sugar E) an RNA nucleotide 79) ______ 80) Which of the following statements is true concerning catabolic pathways? 80) ______ A) They combine molecules into more energy-rich molecules. B) They are spontaneous and do not need enzyme catalysis. C) They build up complex molecules such as protein from simpler compounds. D) They are endergonic. E) They supply energy, primarily in the form of ATP, for the cell's work. 81) When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? 81) ______ A) It is lost to the environment. B) It is transported to specific organs such as the brain. C) It is used to store energy as more ATP. D) It is used to generate ADP from nucleotide precursors. E) It is used to power yet more cellular work. 82) Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's 82) ______ A) endothermic level. B) equilibrium point. C) entropy. D) activation energy. E) free-energy content. 83) Which of the following statements regarding enzymes is true? 83) ______ A) Enzymes increase the rate of a reaction by lowering the activation energy barrier. B) Enzymes change the equilibrium point of the reactions they catalyze. C) Enzymes make the rate of a reaction independent of substrate concentrations. D) Enzymes increase the rate of a reaction by reducing the rate of reverse reactions. E) Enzymes increase the rate of a reaction by making the reaction more exergonic. 84) The active site of an enzyme is the region that 84) ______ A) is inhibited by the presence of a coenzyme or a cofactor. B) binds allosteric regulators of the enzyme. C) is involved in the catalytic reaction of the enzyme. D) binds noncompetitive inhibitors of the enzyme. 85) Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? 85) ______ A) denaturization of the enzyme B) allosteric inhibition C) saturation of the enzyme activity D) competitive inhibition E) insufficient cofactors 86) How does a noncompetitive inhibitor decrease the rate of an enzyme reaction? A) by changing the shape of the enzyme's active site B) by binding at the active site of the enzyme C) by decreasing the activation energy of the reaction D) by acting as a coenzyme for the reaction E) by changing the free energy change of the reaction 86) ______ 87) The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as 87) ______ A) allosteric inhibition. B) metabolic inhibition. C) reversible inhibition. D) noncooperative inhibition. E) feedback inhibition. 88) Allosteric enzyme regulation is usually associated with A) lack of cooperativity. B) activating activity. C) an enzyme with more than one subunit. D) feedback inhibition. E) the need for cofactors. 88) ______ 89) Which of the following is an example of cooperativity? 89) ______ A) one enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway B) a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three C) binding of an ATP molecule along with one of the substrate molecules in an active site D) the effect of increasing temperature on the rate of an enzymatic reaction E) the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway 90) Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? A) cessation of cellular protein synthesis B) hydrophobic interactions C) exporting enzymes out of the cell D) connecting enzymes into large aggregates E) localization of enzymes into specific organelles or membranes 90) ______ 91) What is the term for metabolic pathways that release stored energy by breaking down complex molecules? A) catabolic pathways B) anabolic pathways 91) ______ C) bioenergetic pathways D) fermentation pathways E) thermodynamic pathways 92) The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction 92) ______ A) gains electrons and loses potential energy. B) loses electrons and gains potential energy. C) neither gains nor loses electrons, but gains or loses potential energy. D) loses electrons and loses potential energy. E) gains electrons and gains potential energy. 93) When electrons move closer to a more electronegative atom, what happens? 93) ______ A) The more electronegative atom is oxidized, and energy is released. B) The more electronegative atom is oxidized, and energy is consumed. C) The more electronegative atom is reduced, and entropy decreases. D) The more electronegative atom is reduced, and energy is consumed. E) The more electronegative atom is reduced, and energy is released. 94) Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy 94) ______ A) CO2 is reduced and O2 is oxidized. B) O2 is reduced and CO2 is oxidized. C) C6H12O6 is oxidized and O2 is reduced. D) O2 is oxidized and H2O is reduced. E) C6H12O6 is reduced and CO2 is oxidized. 95) When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes ______ A) hydrolyzed. B) an oxidizing agent. C) reduced. D) oxidized. E) hydrogenated. 96) Where does glycolysis take place in eukaryotic cells? A) mitochondrial inner membrane B) cytosol C) mitochondrial outer membrane D) mitochondrial intermembrane space E) mitochondrial matrix 96) ______ 97) The oxygen consumed during cellular respiration is involved directly in which process or event? A) the oxidation of pyruvate to acetyl CoA B) the citric acid cycle C) glycolysis D) accepting electrons at the end of the electron transport chain E) the phosphorylation of ADP to form ATP 98) Why are carbohydrates and fats considered high energy foods? A) They have a lot of electrons associated with hydrogen. B) They have no nitrogen in their makeup. C) They are easily reduced. D) They have a lot of oxygen atoms. E) They can have very long carbon skeletons. 98) ______ 99) In addition to ATP, what are the end products of glycolysis? A) CO2 and NADH 99) ______ 97) ______ 95) B) H2O, FADH2, and citrate C) CO2 and pyruvate D) NADH and pyruvate E) CO2 and H2O 100) In glycolysis, for each molecule of glucose oxidized to pyruvate 100) _____ A) two molecules of ATP are used and two molecules of ATP are produced. B) two molecules of ATP are used and four molecules of ATP are produced. C) two molecules of ATP are used and six molecules of ATP are produced. D) six molecules of ATP are used and six molecules of ATP are produced. E) four molecules of ATP are used and two molecules of ATP are produced. 101) The transport of pyruvate into mitochondria depends on the proton-motive force across the inner mitochondrial membrane. How does pyruvate enter the mitochondrion? 101) _____ A) diffusion B) facilitated diffusion C) through a channel D) through a pore E) active transport 102) During cellular respiration, acetyl CoA accumulates in which location? A) mitochondrial inner membrane B) cytosol C) mitochondrial outer membrane D) mitochondrial intermembrane space E) mitochondrial matrix 102) _____ 103) During aerobic respiration, electrons travel downhill in which sequence? A) food → glycolysis → citric acid cycle → NADH → ATP B) food → citric acid cycle → ATP → NAD+ C) glucose → pyruvate → ATP → oxygen D) food → NADH → electron transport chain → oxygen E) glucose → ATP → electron transport chain → NADH 103) _____ 104) In cellular respiration, the energy for most ATP synthesis is supplied by A) transferring electrons from organic molecules to pyruvate. B) a proton gradient across a membrane. C) converting oxygen to ATP. D) high energy phosphate bonds in organic molecules. E) generating carbon dioxide and oxygen in the electron transport chain. 104) _____ 105) The primary role of oxygen in cellular respiration is to 105) _____ A) yield energy in the form of ATP as it is passed down the respiratory chain. B) combine with lactate, forming pyruvate. C) combine with carbon, forming CO2. D) catalyze the reactions of glycolysis. E) act as an acceptor for electrons and hydrogen, forming water. 106) Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells? A) mitochondrial inner membrane B) mitochondrial matrix C) mitochondrial intermembrane space D) mitochondrial outer membrane E) cytosol 107) Where is ATP synthase located in the mitochondrion? A) inner membrane B) mitochondrial matrix 107) _____ 106) _____ C) electron transport chain D) cytosol E) outer membrane 108) How many oxygen molecules (O2) are required each time a molecule of glucose (C6H12O6) is completely oxidized to carbon dioxide and water via aerobic respiration,? 108) _____ A) 1 B) 12 C) 3 D) 6 E) 30 109) Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water? 109) _____ A) glycolysis B) oxidation of pyruvate to acetyl CoA C) fermentation D) citric acid cycle E) oxidative phosphorylation (chemiosmosis) 110) The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of 110) _____ A) an endergonic reaction coupled to an exergonic reaction. B) active transport. C) allosteric regulation. D) osmosis. E) a reaction with a positive ∆G . 111) In prokaryotes, the respiratory electron transport chain is located 111) _____ A) in the cytoplasm. B) in the mitochondrial outer membrane. C) in the bacterial outer membrane. D) in the mitochondrial inner membrane. E) in the plasma membrane. 112) Which of the following occurs in the cytosol of a eukaryotic cell? 112) _____ A) fermentation and chemiosmosis B) glycolysis and fermentation C) oxidative phosphorylation D) oxidation of pyruvate to acetyl CoA E) citric acid cycle 113) What is the purpose of beta oxidation in respiration? A) breakdown of fatty acids B) oxidation of glucose C) oxidation of pyruvate D) feedback regulation E) control of ATP accumulation 113) _____ 114) Where do the catabolic products of fatty acid breakdown enter into the citric acid cycle? A) α-ketoglutarate B) succinyl CoA C) malate or fumarate D) acetyl CoA E) pyruvate 114) _____ 115) What carbon sources can yeast cells metabolize to make ATP from ADP under anaerobic conditions? 115) _____ A) lactic acid B) either ethanol or lactic acid C) pyruvate D) ethanol E) glucose 116) When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? _____ 116) A) The pH of the matrix increases. B) The cytochromes phosphorylate ADP to form ATP. C) ATP synthase pumps protons by active transport. D) The electrons gain free energy. E) NAD+ is oxidized. 117) Most CO2 from catabolism is released during A) the citric acid cycle. B) electron transport. C) lactate fermentation. D) glycolysis. E) oxidative phosphorylation. 117) _____ 118) Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? _____ A) CO2 and glucose B) ATP and NADPH C) ADP, i, and NADP+ D) electrons and H+ E) H2O and O2 119) Photosynthesis is not responsible for 119) _____ A) oxygen in the atmosphere. B) atmospheric CO2. C) most of the organic carbon on Earth's surface. D) fossil fuels. E) the ozone layer. 120) Where does the Calvin cycle take place? A) interior of the thylakoid (thylakoid space) B) cytoplasm surrounding the chloroplast C) outer membrane of the chloroplast D) thylakoid membrane E) stroma of the chloroplast 120) _____ 121) In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary? A) producers and primary consumers B) autotrophs C) photosynthesizers D) autotrophs and heterotrophs E) green plants 122) Which of the following are directly associated with photosystem I? A) extraction of hydrogen electrons from the splitting of water B) generation of molecular oxygen C) passing electrons to the thylakoid membrane electron transport chain D) harvesting of light energy by ATP E) receiving electrons from the thylakoid membrane electron transport chain 123) What are the products of linear photophosphorylation? A) ATP and P700 B) ADP and NADP C) ATP and NADPH D) heat and fluorescence 123) _____ 121) _____ 122) _____ 118) E) P700 and P680 124) In a plant cell, where are the ATP synthase complexes located? A) thylakoid membrane only B) plasma membrane only C) inner mitochondrial membrane only D) thylakoid membrane and plasma membrane E) thylakoid membrane and inner mitochondrial membrane 124) _____ 125) Where are the molecules of the electron transport chain found in plant cells? A) thylakoid membranes of chloroplasts B) outer membrane of mitochondria C) cytoplasm D) stroma of chloroplasts E) matrix of mitochondria 126) Reduction of oxygen to form water occurs during A) photosynthesis only. B) photorespiration only. C) respiration only. D) neither photosynthesis nor respiration. E) both photosynthesis and respiration. 125) _____ 126) _____ 127) What is the relationship between wavelength of light and the quantity of energy per photon? 127) _____ A) They are inversely related. B) They are only related in certain parts of the spectrum. C) They are separate phenomena. D) They have a direct, linear relationship. E) They are logarithmically related. 128) In thylakoids, protons travel through ATP synthase from the thylakoid space to the stroma. Therefore, the catalytic "knobs" of ATP synthase would be located 128) _____ A) on the stromal side of the membrane. B) on the side facing the thylakoid space. C) on the ATP molecules themselves. D) on the pigment molecules of photosystem I and photosystem II. E) built into the center of the thylakoid stack (granum). 129) The reactions that produce molecular oxygen (O2) take place in A) the chloroplast, but are not part of photosynthesis. B) the Calvin cycle alone. C) the light reactions alone. D) both the light reactions and the Calvin cycle. E) neither the light reactions nor the Calvin cycle. 129) _____ 130) The accumulation of free oxygen in Earth's atmosphere began 130) _____ A) with the origin of life and respiratory metabolism. B) with the origin of cyanobacteria that had both photosystem I and photosystem II. C) with the origin of chloroplasts in photosynthetic eukaryotic algae. D) with the origin of land plants. E) with the origin of photosynthetic bacteria that had photosystem I. 131) Where do the enzymatic reactions of the Calvin cycle take place? 131) _____ A) matrix of the mitochondria B) stroma of the chloroplast C) cytosol around the chloroplast D) thylakoid membranes E) thylakoid space 132) What is the primary function of the Calvin cycle? 132) _____ A) use ATP to release carbon dioxide B) transport RuBP out of the chloroplast C) split water and release oxygen D) use NADPH to release carbon dioxide E) synthesize simple sugars from carbon dioxide 133) In C3 photosynthesis, the reactions that require ATP take place in 133) _____ A) the light reactions alone. B) the chloroplast, but is not part of photosynthesis. C) neither the light reactions nor the Calvin cycle. D) the Calvin cycle alone. E) both the light reactions and the Calvin cycle. 134) In a plant leaf, the reactions that produce NADH occur in 134) _____ A) the Calvin cycle alone. B) neither the light reactions nor the Calvin cycle. C) the light reactions alone. D) both the light reactions and the Calvin cycle. E) the chloroplast, but is not part of photosynthesis. 135) Reactions that require CO2 take place in 135) _____ A) both the light reactions and the Calvin cycle. B) the Calvin cycle alone. C) the chloroplast, but is not part of photosynthesis. D) the light reactions alone. E) neither the light reactions nor the Calvin cycle. 136) The phylogenetic distribution of the enzyme rubisco is limited to 136) _____ A) C3 plants only. B) all living cells. C) all known photoautotrophs, both bacterial and eukaryotic. D) C3 and C4 plants. E) all photosynthetic eukaryotes. 137) Why are C4 plants able to photosynthesize with no apparent photorespiration? A) They exclude oxygen from their tissues. B) They use PEP carboxylase to initially fix CO2. C) They are adapted to cold, wet climates. D) They conserve water more efficiently. E) They do not participate in the Calvin cycle. 137) _____ 138) Compared to C3 plants, C4 plants 138) _____ A) can continue to fix CO2 even at relatively low CO2 concentrations and high oxygen concentrations. B) make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria. C) do not use rubisco for carbon fixation. D) grow better under cool, moist conditions. E) have higher rates of photorespiration. 139) If atmospheric CO2 concentrations increase twofold or more, how will plants be affected, disregarding any changes in climate? 139) _____ A) All plants will experience increased rates of photosynthesis. B) C3 plants will have faster growth; C4 plants will have slower growth. C) C3 plants will have faster growth; C4 plants will be minimally affected. D) C4 plants will have faster growth; C3 plants will be minimally affected. E) Plant growth will not be affected because atmospheric CO2 concentrations are never limiting for plant growth. 140) Plants photosynthesize only in the light. Plants respire A) in the light only. 140) _____ B) never–they get their ATP from photophosphorylation. C) both in light and dark. D) only when excessive light energy induces photorespiration. E) in the dark only. 141) Which of the following statements is a correct distinction between autotrophs and heterotrophs? 141) _____ A) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. B) Only heterotrophs have mitochondria. C) Only heterotrophs require oxygen. D) Cellular respiration is unique to heterotrophs. E) Only heterotrophs require chemical compounds from the environment. 1) A 2) C 3) C 4) A 5) B 6) A 7) D 8) C 9) E 10) E 11) B 12) D 13) E 14) D 15) D 16) A 17) B 18) E 19) E 20) B 21) D 22) E 23) E 24) E 25) B 26) A 27) E 28) B 29) B 30) A 31) E 32) C 33) B 34) D 35) B 36) C 37) B 38) A 39) E 40) E 41) E 42) C 43) B 44) D 45) D 46) B 47) A 48) E 49) A 50) B 51) A 52) E 53) D 54) B 55) A 56) B 57) C 58) B 59) A 60) D 61) E 62) B 63) A 64) A 65) D 66) A 67) B 68) E 69) E 70) B 71) A 72) E 73) C 74) C 75) D 76) A 77) D 78) D 79) E 80) E 81) A 82) D 83) A 84) C 85) D 86) A 87) E 88) C 89) B 90) E 91) A 92) D 93) E 94) C 95) D 96) B 97) D 98) A 99) D 100) B 101) E 102) E 103) D 104) B 105) E 106) C 107) A 108) D 109) E 110) A 111) E 112) B 113) A 114) D 115) E 116) A 117) A 118) B 119) D 120) E 121) B 122) E 123) C 124) E 125) A 126) C 127) A 128) A 129) C 130) B 131) B 132) E 133) D 134) B 135) B 136) C 137) B 138) A 139) C 140) C 141) A