AP Bio Ch. 7

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Glycolysis occurs where?
a) cytosol
b) mitochondrial matrix
c) intermembrane space
d) inner mitochondrial membrane
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Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops.
Which of these statements is the correct explanation for this observation?
a)Oxygen is required to convert glucose to pyruvate in glycolysis. Without oxygen, no pyruvate can be made.
b) In the absence of oxygen, electron transport stops. NADH is no longer converted to NAD+, which is needed for the first three stages of cellular respiration.
c) ATP is needed to convert pyruvate to acetyl CoA. Without oxygen, no ATP can be made in oxidative phosphorylation.
d) Oxygen is an input to acetyl CoA formation.
Suppose that a cell's demand for ATP suddenly exceeds its supply of ATP from cellular respiration.
Which statement correctly describes how this increased demand would lead to an increased rate of ATP production?
a) ATP levels would rise at first, increasing the inhibition of PFK and increasing the rate of ATP production.
b) ATP levels would rise at first, decreasing the inhibition of PFK and increasing the rate of ATP production.
c) ATP levels would fall at first, decreasing the inhibition of PFK and increasing the rate of ATP production.
d) ATP levels would fall at first, increasing the inhibition of PFK and increasing the rate of ATP production.
During strenuous exercise, anaerobic conditions can result if the cardiovascular system cannot supply oxygen fast enough to meet the demands of muscle cells. Assume that a muscle cell's demand for ATP under anaerobic conditions remains the same as it was under aerobic conditions.
What would happen to the cell's rate of glucose utilization?
a) Glucose utilization would increase a lot.
b) Glucose utilization would increase a little.
c) Glucose utilization would remain the same.
d) Glucose utilization would decrease a lot.
What molecules belong in spaces E and F? a) glucose and oxygen b) oxygen and water c) carbon dioxide and oxygen d) carbon dioxide and waterdWhat process occurs in Box A? a) glycolysis b) electron transport c) electron transport and oxidative phosphorylation d) oxidative phosphorylationaWhat process occurs within Box B? a) glycolysis b) oxidative phosphorylation c) electron transport d) the citric acid cycledWhat molecule is indicated by the letter D? a) glucose b) pyruvate c) ATP d) oxygendWhich of the following best describes the main purpose of the combined processes of glycolysis and cellular respiration? a) transforming the energy in glucose and related molecules in a chemical form that cells can use for work b) breaking down ATP, so that ADP and P can be reused c) producing complex molecules from chemical building blocks d) catabolism of sugars and related compoundsaIn the combined processes of glycolysis and cellular respiration, what is consumed and what is produced? a) Water is consumed, and ATP is produced. b) ATP is consumed, and oxygen is produced. c) Carbon dioxide is consumed, and water is produced. d) Glucose is consumed, and carbon dioxide is produced.dWhat is the term for metabolic pathways that release stored energy by breaking down complex molecules? a) catabolic pathways b) thermodynamic pathways c) bioenergetic pathways d) anabolic pathwaysaThe molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction a) loses electrons and gains potential energy. b) gains electrons and gains potential energy. c) gains electrons and loses potential energy. d) loses electrons and loses potential energy.dWhen electrons move closer to a more electronegative atom, what happens? 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 energy is released. d) The more electronegative atom is reduced, and entropy decreases.cWhy does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy? a) The oxidation of organic compounds can be used to make ATP. b) The covalent bonds in organic molecules and molecular oxygen have more kinetic energy than the covalent bonds in water and carbon dioxide. c) The electrons have a higher potential energy when associated with water and CO2 than they do in organic compounds. d) Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O).dWhich of the following statements describes the results of this reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy a) C6H12O6 is oxidized and O2 is reduced. b) C6H12O6 is reduced and CO2 is oxidized. c) O2 is oxidized and H2O is reduced. d) O2 is reduced and CO2 is oxidized.aWhen a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes a) hydrogenated. b) reduced. c) hydrolyzed. d) oxidized.dWhen a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes a) oxidized. b) dehydrogenated. c) redoxed. d) reduced.dWhich of the following statements describes NAD+? a) In the absence of NAD+, glycolysis can still function. b) NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle. c) NAD+ is oxidized by the action of hydrogenases. d) NAD+ can donate electrons for use in oxidative phosphorylation.bWhere does glycolysis take place in eukaryotic cells? a) cytosol b) mitochondrial matrix c) mitochondrial outer membrane d) mitochondrial intermembrane spaceaThe ATP made during glycolysis is generated by a) oxidation of NADH to NAD+. b) electron transport. c) photophosphorylation. d) substrate-level phosphorylation.dThe oxygen consumed during cellular respiration is involved directly in which process or event? a) the citric acid cycle b) glycolysis c) the oxidation of pyruvate to acetyl CoA d) accepting electrons at the end of the electron transport chaindAn electron loses potential energy when it a) increases its activity as an oxidizing agent. b) shifts to a less electronegative atom. c) shifts to a more electronegative atom. d) increases its kinetic energy.cWhy are carbohydrates and fats considered high-energy foods? a) They can have very long carbon skeletons. b) They are easily reduced. c) They have no nitrogen in their makeup. d) They have a lot of electrons associated with hydrogen.dDuring aerobic respiration, electrons travel downhill in which sequence? a) food → glycolysis → citric acid cycle → NADH → ATP b) food → NADH → electron transport chain → oxygen c) glucose → pyruvate → ATP → oxygen d) glucose → ATP → electron transport chain → NADHbEven though plants carry on photosynthesis, plant cells still use their mitochondria for oxidation of pyruvate. When and where will this occur? a) in photosynthesizing cells in the light and in other tissues in the dark b) in cells that are storing glucose only c) in nonphotosynthesizing cells only d) in all cells all the timedAmong the products of glycolysis, which compounds contain energy that can be used by other biological reactions? a) pyruvate, ATP, and NADH b) ATP only c) ATP and NADH only d) CO2 onlyaHow many NADH are produced by glycolysis? a) 1 b) 2 c) 3 d) 4bIn glycolysis, ATP molecules are produced by _____. a) cellular respiration b) substrate-level phosphorylation c) oxidative phosphorylation d) photophosphorylationbWhich of these is NOT a product of glycolysis? a) pyruvate b) NADH c) ATP d) FADH2dIn glycolysis, what starts the process of glucose oxidation? a) ATP b) FADH2 c) ADP d) NADPHaIn glycolysis there is a net gain of _____ ATP. a) 1 b) 2 c) 3 d) 4bWhich process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent? a) electron transport b) the citric acid cycle c) glycolysis d) chemiosmosiscDuring glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of the potential energy contained in glucose is a) retained in the two pyruvates. b) transferred to ADP, forming ATP. c) stored in the NADH produced. d) transferred directly to ATP.aIn addition to ATP, what are the end products of glycolysis? a) H2O, FADH2, and citrate b) CO2 and NADH c) NADH and pyruvate d) CO2 and H2OcThe free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol and the free energy for the reduction of NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed? a) Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis. b) Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis. c) There is no CO2 or water produced as products of glycolysis. d) Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat.aStarting with one molecule of glucose, the energy-containing products of glycolysis are a) 6 CO2, 2 pyruvate, and 30 ATP. b) 2 FADH2, 2 pyruvate, and 4 ATP. c) 2 NADH, 2 pyruvate, and 2 ATP. d) 6 CO2, 2 pyruvate, and 2 ATP.cA molecule that is phosphorylated a) has an increased chemical potential energy; it is primed to do cellular work. b) has a decreased chemical reactivity; it is less likely to provide energy for cellular work. c) has been oxidized as a result of a redox reaction involving the gain of an inorganic phosphate. d) has less energy than before its phosphorylation and therefore less energy for cellular work.aWhich kind of metabolic poison would most directly interfere with glycolysis? a) an agent that closely mimics the structure of glucose but is not metabolized b) an agent that binds to pyruvate and inactivates it c) an agent that reacts with oxygen and depletes its concentration in the cell d) an agent that reacts with NADH and oxidizes it to NAD+aWhere are the proteins of the electron transport chain located? a) mitochondrial inner membrane b) mitochondrial outer membrane c) cytosol d) mitochondrial intermembrane spaceaIn cellular respiration, the energy for most ATP synthesis is supplied by a) high-energy phosphate bonds in organic molecules. b) converting oxygen to ATP. c) a proton gradient across a membrane. d) transferring electrons from organic molecules to pyruvate.cDuring aerobic respiration, H2O is formed. Where does the oxygen atom for the formation of the water come from? a) molecular oxygen (O2) b) lactate (C3H5O3-) c) carbon dioxide (CO2) d) glucose (C6H12O6)aIn chemiosmosis, what is the most direct source of energy that is used to convert ADP + i to ATP? a) energy released from dehydration synthesis reactions b) energy released from movement of protons through ATP synthase, down their electrochemical gradient c) No external source of energy is required because the reaction is exergonic. d)energy released from substrate-level phosphorylationbEnergy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells? a) cytosol b) mitochondrial inner membrane c) mitochondrial matrix d) mitochondrial intermembrane spacedWhen hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is a) the creation of a proton-motive force. b) the restoration of the Na+/K+ balance across the membrane. c)the formation of ATP. d) the reduction of NAD+.aWhere is ATP synthase located in the mitochondrion? a) cytosol b) electron transport chain c) inner membrane d) mitochondrial matrixcWhich of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water? a) oxidative phosphorylation (chemiosmosis) b) glycolysis c) fermentation d) citric acid cycleaThe 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 a) osmosis. b) allosteric regulation. c) a reaction with a positive ΔG . d) an endergonic reaction coupled to an exergonic reaction.dWhat is proton-motive force? a) the force that moves hydrogen to NAD+ b) the force required to remove an electron from hydrogen c) the force that moves hydrogen into the mitochondrion d) the force provided by a transmembrane hydrogen ion gradientdBrown fat cells produce a protein called thermogenin in their mitochondrial inner membrane. Thermogenin is a channel for facilitated transport of protons across the membrane. What will occur in the brown fat cells when they produce thermogenin? a) ATP synthesis will increase, and heat generation will decrease. b) ATP synthesis and heat generation will stay the same. c) ATP synthesis will decrease, and heat generation will increase. d)ATP synthesis will increase, and heat generation will decrease.cWhich molecule is metabolized in a cell to produce energy for performing work? a) ADP b) ATP c) Phosphate d) GlucosedTrue or false? The potential energy in an ATP molecule is derived mainly from its three phosphate groups. a) True b) False c) x d) xaWhich process is not part of the cellular respiration pathway that produces large amounts of ATP in a cell? a) Glycolysis b) Electron Transport Chain c) Krebs Cycle d) FermentationdWhich step of the cellular respiration pathway can take place in the absence of oxygen? a) Glycolysis b) Electron Transport Chain c) Krebs Cycle d) FermentationaInto which molecule are all the carbon atoms in glucose ultimately incorporated during cellular respiration? a) Carbon dioxide b) Water c) ATP d) NADHaWhich of the following statements about the electron transport chain is true? a) Electrons gain energy as they move down the chain. b) NADH and FADH2 donate their electrons to the chain. c) Water is the last electron acceptor. d) The electron transport chain is the first step in cellular respiration.bWhich stage of glucose metabolism produces the most ATP? a) Fermentation of pyruvate to lactate b) Electron transport and chemiosmosis c) Glycolysis d) Krebs cyclebTrue or false? The reactions that generate the largest amounts of ATP during cellular respiration take place in the mitochondria. a) True b) False c) x d) xaIn the absence of oxygen, what is the net gain of ATP for each glucose molecule that enters glycolysis? a) four ATP b) two ATP c) up to 30 ATP d) none, because in the absence of oxygen, no ATP can be madebWhat carbon sources can yeast cells metabolize to make ATP from ADP under anaerobic conditions? a) lactic acid b) glucose c) ethanol d) pyruvatebYeast cells that have defective mitochondria incapable of respiration will be able to grow by catabolizing which of the following carbon sources for energy? a) fatty acids b) proteins c) glucose d) glucose, proteins, and fatty acidscWhich of the following normally occurs regardless of whether or not oxygen (O2) is present? a) citric acid cycle b) fermentation c) glycolysis d) oxidation of pyruvate to acetyl CoAcWhich of the following occur(s) in the cytosol of a eukaryotic cell? a) oxidative phosphorylation b) oxidation of pyruvate to acetyl CoA c) citric acid cycle d) glycolysis and fermentationdWhich metabolic pathway is common to both cellular respiration and fermentation? a) the oxidation of pyruvate to acetyl CoA b) chemiosmosis c) glycolysis d) oxidative phosphorylationcThe ATP made during fermentation is generated by which of the following? a) chemiosmosis b) substrate-level phosphorylation c) aerobic respiration d) oxidative phosphorylationbIn the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of a) ATP, pyruvate, and acetyl CoA. b) ATP, pyruvate, and oxygen. c) ATP, CO2, and lactate. d) ATP, CO2, and ethanol (ethyl alcohol).dOne function of both alcohol fermentation and lactic acid fermentation is to a) reduce FAD+ to FADH2. b) reduce NAD+ to NADH. c) oxidize NADH to NAD+. d) do none of the above.cAn organism is discovered that thrives both in the presence and absence of oxygen in the air. Curiously, the consumption of sugar increases as oxygen is removed from the organism's environment, even though the organism does not gain much weight. This organism a) is a facultative anaerobe. b) is an anaerobic organism. c) is a normal eukaryotic organism. d) is photosynthetic.aWhen an individual is exercising heavily and when the muscle becomes oxygen-deprived, muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells? a) It produces CO2 and water. b) It reduces FADH2 to FAD+. c) It is taken to the liver and converted back to pyruvate. d) It is converted to NAD+.cA mutation in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells? a) The mutant yeast will be unable to grow anaerobically. b) The mutant yeast will metabolize only fatty acids. c) The mutant yeast will grow anaerobically only when given glucose. d) The mutant yeast will be unable to metabolize glucose.aYou have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and exercise. How did the fat leave her body? a) It was converted to ATP, which weighs much less than fat. b) It was converted to urine and eliminated from the body. c) It was converted to heat and then released. d) It was released as CO2 and H2O.dDuring intense exercise, as skeletal muscle cells switch to fermentation, the human body will increase its catabolism of a) proteins only. b) fats only. c) carbohydrates only. d) fats and proteins only.cIdentify the correct statement about the basic function of fermentation. a) The basic function of fermentation is the regeneration of NAD+, which allows continued ATP production by glycolysis. b) The basic function of fermentation is the production of additional ATP by further oxidation of the products of glycolysis. c) The basic function of fermentation is the production of ethyl alcohol or lactic acid. d) All of the aboveaWhich term describes the degree to which an element attracts electrons? a) Polarity. b) Electronegativity. c) Reduction. d) Oxidation.bWhich terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other? a) Anion and cation. b) Proton and electron. c) Polar and nonpolar. d) Ionic and covalent.aWhich of the following statements is true of the bonds in a water molecule? a)The electron in each hydrogen atom is completely transferred to the oxygen atom, and each hydrogen atom has a net charge of +1. b) Oxygen acts as the electron acceptor and is oxidized. c) There is equal sharing of the electrons between the oxygen atom and the two hydrogen atoms, and the net charge is zero. d) Oxygen holds electrons more tightly than hydrogen does, and the net charge is zero.dWhich of the following statements is not true of most cellular redox reactions? a) A hydrogen atom is transferred to the atom that loses an electron. b) The electron acceptor is reduced. c) Changes in potential energy can be released as heat. d) The reactant that is oxidized loses electrons.aGaseous hydrogen burns in the presence of oxygen to form water: 2H2 + O2 → 2H2 O + energy Which molecule is oxidized and what kind of bond is formed? a) Oxygen, nonpolar. b) Hydrogen, nonpolar. c) Oxygen, polar. d) Hydrogen, polar.dIn mitochondrial electron transport, what is the direct role of O2? a) to oxidize NADH and FADH2 from glycolysis, acetyl CoA formation, and the citric acid cycle b) to provide the driving force for the production of a proton gradient c) to function as the final electron acceptor in the electron transport chain d) to provide the driving force for the synthesis of ATP from ADP and PicHow would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation? (Note that you should not consider the effect on ATP synthesis in glycolysis or the citric acid cycle.) a) Neither electron transport nor ATP synthesis would be affected. b) Electron transport would be unaffected but ATP synthesis would stop. c) Electron transport would stop but ATP synthesis would be unaffected. d) Both electron transport and ATP synthesis would stop.dIn muscle cells, fermentation produces _____. a) pyruvate b) lactate, NADH, and ATP c) carbon dioxide, ethanol, and NAD+ d) lactate and NAD+dIn fermentation _____ is reduced and _____ is oxidized. a) NADH ... lactate b) pyruvate ... NADH c) NAD+ ... pyruvate d) lactate ... NADHb