BIO-152

Card Set Information

Author:
ihalghanimi
ID:
137491
Filename:
BIO-152
Updated:
2012-02-24 23:36:57
Tags:
Biology
Folders:

Description:
Chapters 7-10
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user ihalghanimi on FreezingBlue Flashcards. What would you like to do?


  1. A single layer of phosolipid molecules coats the water in a beaker. Which part of the molecules will face the air?
    a. the phosphate groups
    b. the hydrocarbon tails
    c. both head and tail because the molecules are amphipathic and will lie sideways
    d. the glycolipid regions
    e. the phospholipids would dissolve in the water and not form a membrane coat.
    b. the hydrocarbon tails
  2. Glycoproteins and glycolipids are important for
    a. facilitated diffusion
    b. active transport
    c.cell-cell recognition
    d.cotransport
    e. signal-transduction pathways
    c. cell-cell recognition
  3. Which of the following is not true about osmosis?
    a. It is passive process in cells without walls, but an active one in cells with walls.
    b. Water moves from a hypotonic to a hypertonic solution.
    c. Solute molecules bind to water and decrease the water available to move.
    d. It can occur more rapidly through chaneel proteins known as aquaporins.
    e. There is no net osmosis between isotonic solutions.
    a. It is passive process in cells without walls, but an active one in cells with walls.
  4. Support for the fluid mosaic model of membrane structure comes from
    a. the freeze-fracture technique of electron microscopy
    b. the movement of proteins in hybrid cells.
    c. the amphipathic nature of many membrane
    d. both a and c.
    e. all of the above
    e. all of the above
  5. Facilitated diffusion of ions across a cellular membrane requires _______ and the ions move _______.
    a. energy and transport proteins....against their elextrochemical gradient
    b. energy and transport proteins... against their concentration gradient.
    c. cotransport proteins... against their electrochemical gradient.
    d. transport proteins.. down their electrochemical gradient
    e. transport proteins...down their concentration gradient.
    d. transport proteins.. down their electrochemical gradient
  6. Which of the following is the most probabke description of an integral, transmembrane protein?
    a. amphipathic with a hydrophilic head and a hydrophobic tail region
    b. a globular protein with hydrophobic amino acids in the interior and hydrophilic amino acids arranged around the outside
    c. a fibrous protein coated with hydrophobic fatty acids
    d. a glycolipid attached to the portion of the protein facing the exterior of the cell and cytiskeletal elements attached to the portion facing inside the cell
    e. a middle region composed of a helical stretches of hydrophobic amino acids, with hydrophilic regions at both ends of the protein.
    e. a middle region composed of a helical stretches of hydrophobic amino acids, with hydrophilic regions at both ends of the protein.
  7. The fluidity of membranes in aplant in cold weather may be maintained by increasing the
    a. number of phospholipids with saturated hydrocarbon tails
    b. action of an H+ pump.
    c. concentration of cholesterol in the membrane
    d. proprotion of peripheral proteins.
    e. number of phospholipids with unsaturated hydrocarbon tails.
    e. number of phospholipids with unsaturated hydrocarbon tails.
  8. An animal cell placed in a hypotonic environment will
    a. plasmolyze
    b. shrivel
    c. become turgid
    d. become flaccid
    e. burst(lyse)
    e. burst(lyse)
  9. Which of the following is not true of carrier molecules involved in facilitated diffusion?
    a. they increase the speed of transport across a membrane
    b. they can concentrate solute molecules on one side of the membrane
    c. they may have specific binding sites for the molecules they transport
    d. they may undergo a change in shape upon binding of solute
    e. they do not require an energy investment from the cell to operate.
    b. they can concentrate solute molecules on one side of the membrane
  10. The membrane potential of a cell favors
    a. the movement of cations into the cell.
    b. the movement of anions into the cell.
    c. the action of an electrogenic pump
    d. the movement of sodium out of the cell.
    e. both b and d.
    a. the movement of cations into the cell
  11. Cotransport may involve
    a. active transport of two solutes through a transport protein
    b. passive transport of two solutes through a transport protein.
    c. ion diffusion against the electrochemical gradient created by an electrogenic pump
    d. a pump such as the sodium-potassium pump that moves ions in two different directions.
    e. transport of one solute against its concentration gradient in tandem with another that is diffusing down its concentration gradient
    e. transport of one solute against its concentration gradient in tandem with another that is diffusing down its concentration gradient
  12. Exocytosis may involve all of the following except
    a. ligands and coated pits
    b. the fusion of a vesicle with the plasma membrane.
    c. a mechanism to export some carbohydrates during the formation of plant cell walls.
    d. a mechanism to rejuvenate the plasma membrane.
    e. a means of exporting large molecules.
    a. ligands and coated pits
  13. The proton pump in plant cells is the functional equivalent of an animal cell's
    a. cotransport mechanism
    b. sodium-potassium pump
    c. contractile vacuole for osmoregulation
    d. receptor-mediated endocytosis of cholesterol.
    e. ATP pump
    b. sodium-potassium pump
  14. Pinocytosis involves
    a. the fusion of of a newly formed food vacuole with a lysosome.
    b. receptor-mediated endocytosis that involves binding of a ligand.
    c. the pinching in of the plasma membrane around small droplets of external fluid.
    d. the secretion of cell fluid
    e. the accumulation of specific molecules in a cell.
    c. the pinching in of the plasma membrane around small droplets of external fluid.
  15. Watering a houseplant with too concentrated a solution of fertilizer can result in wilting because
    a. the uptake of ions into plant cells makes the cells hypertonic
    b. the soil solution becomes hypertonic, causing the cells to lose water
    c. the plant will grow faster than it can transport water and maintain proper water balance
    d. diffusion down the electrochemical gradient will cause a disruption of membrane potential and accompanying loss of water.
    e. the plant will suffer fertilizer burn due to a caustic soil solution.
    b. the soil solution becomes hypertonic, causing the cells to lose water
  16. A cell is manufacturing receptor proteins for cholesterol. How would those proteins be oriented in the following membranes before they reach the plasma membrane?
    a. facing inside the ER lumen but outside the transport vesicle mebrane
    b. facing inside the ER lumen and inside the transport vesicle
    c. attached outiside the ER but facing inside the transport vesicle
    d. attached outside the ER but facing inside the transport vesicle
    e. embedded in the hydrophobic center of both the ER and transport vesicle membranes.
    b. facing inside the ER lumen and inside the transport vesicle
  17. Catabolic and anabolic pathways are often coupled in a cell because
    a. the intermediates of catabolic pathway are used in the anabolic pathway.
    b. both pathways use the same enzymes
    c. the free energy released from one pathway is used to drive the other
    d. the activation energy of the catabolic pathway can be used in the anabolic oathway
    e. their enzymes are controlled by the same activators and inhibitors.
    c. the free energy released from one pathway is used to drive the other
  18. When glucose and O2 are converted to CO2 and H2O, changes in total energy, entropy, and free energy are as follows:
    a. -ΔH, -ΔS, -ΔG
    b. -ΔH, +ΔS, -ΔG
    c.-ΔH, +ΔS, +ΔG
    d. +ΔH, +ΔS, +ΔG
    e. +ΔH, -ΔS, +ΔG
    b. -ΔH, +ΔS, -ΔG
  19. When amino acids join to form a protein, the following energy and entropy changes apply:
    a. +ΔH, -ΔS, +ΔG
    b. +ΔH, +ΔS, -ΔG
    c. +ΔH, +ΔS, -ΔG
    d. -ΔH, +ΔS, +ΔG
    e. -ΔH, -ΔS, +ΔG
    a. +ΔH, -ΔS, +ΔG
  20. A negative ΔG means that
    a. the quantity G of energy is available to do work
    b. the reaction is spontaneous
    c. the reactants have more free energy than the products
    d. the reaction is exergonic
    e. all of the above are true.
    e. all of the above are true.
  21. According to the first law of thermodynamics,
    a. for every action there is an equal and opposite reaction
    b. every energy transger results in an increase in disorder or entropy
    c. the total amount of energy in the universe is conserved or constant
    d. energy can be transferred or transformed, but disorder always increases
    e. potential energy is converted to kinetic energy, and kinetic energy is converted to heat
    c. the total amount of energy in the universe is conserved or constant
  22. What is meant by an induced fit?
    a. the binding of the substrate is an energy-requiring process.
    b. a competitive inhibitor can outcompete the substrate for the active site.
    c. the binding of the substrate changes the shape of the active site, which can stress or bend substrate bonds.
    d. the active site creates a microenvironment ideal for the reaction.
    e. substrates are held in the active site by hydrogen and ionic bonds.
    c. the binding of the substrate changes the shape of the active site, which can stress or bend substrate bonds.
  23. One way in which a cell maintains metabolic disequilibrium is to
    a. siphon products of a reaction off to the next step in a metabolic pathway
    b. provide a constant supply of enzymes for critical reactions
    c. use feedback inhibition to turn off pathways
    d. use allosteric enzymes that can bind to activators or inhibitors
    e. use the energy from anabolic pathways to drive catabolic pathways.
    a. siphon products of a reaction off to the next step in a metabolic pathway
  24. In an experiment, changing the pH from 7 to 6 resulted in an increase in product formation. From this we could conclude that
    a. the enzyme becames saturated at pH 6
    b. the enzyme's optimal pH is 6
    c. the enzyme works best in a neutral pH
    d. the temperature must have increased when the pH was changed to 6
    e. the enzymes was in a more active shape at pH 6
    e. the enzymes was in a more active shape at pH 6
  25. When substance A was added to an enzyme reaction, product formation decreased. The addition of more substrate did not increase product formation. From this we conclude that substance A could be
    a. product molecules
    b. a cofactor
    c. an allosteric enzyme
    d. a competitive inhibitor
    e. a noncompetitive inhibitor
    e. a noncompetitive inhibitor
  26. The formation of ATP from ADP and inorganic phosphate
    a. is an exergonic process.
    b. transfers the phosphate to another intermediate that becomes more reactive
    c. produces an unstable energy compound that can drive cellular work
    d. has a ΔG of -7.3 kcal/mol under standard conditions
    e. involves the hydrolysis of a phosphate bond.
    c. produces an unstable energy compound that can drive cellular work
  27. At equilibrium
    a. no enzymes are functioning
    b. free energy is at a minimum
    c. the forward and backward reactions have stopped
    d. the products and reactants have equal values of H
    e. a reaction has +ΔG.
    b. free energy is at a minimum
  28. In cooperativity,
    a. a cellular organelle contains all the enzymes needed for a metabolic pathway
    b. a product of a pathway serves as a competitive inhibitor of an early enzyme in the pathway
    c. a molecule bound to the active site of one subunit of an enzyme affects the active site of other subunits
    d. the allosteric site is filled with an activator molecule
    e. the product of one reaction serves as the substrate for the next in intricately ordered metabolic pathways.
    c. a molecule bound to the active site of one subunit of an enzyme affects the active site of other subunits
  29. When a cell breaks down glucose, only about 40% of the energy is captured in ATP molecules. The remaining 60% of the energy is
    a. used to increase the order necessary for life to exist
    b. lost as heat, in accordance with the second law of thermodynamics
    c. used to increase the entropy of the system by converting kinetic energy into potential energy
    d. stored in starch or glycogen for use later by the cell
    e. released when the ATP molecules are hydrolyzed.
    b. lost as heat, in accordance with the second law of thermodynamics
  30. An endergonic reaction could be described as one that will
    a. proceed spontaneously with the addition of activation energy
    b. produce products with more free energy than the reactants
    c. not be able to be catalyzed by enzymes
    d. release energy
    e. produce ATP for energy coupling.
    b. produce products with more free energy than the reactants
  31. What is most directly responsible for the specificity of a protein enzyme?
    a. its primary structure
    b. its secondary amd tertiary structure
    c. the shape and characteristics of its allosteric site
    d. its cofactors
    e. the R groups of the amino acids in its active site
    e. the R groups of the amino acids in its active site
  32. Which of the following parameters does an enzyme raise?
    a. ΔG
    b. ΔH
    c. equilibrium of a reaction
    d. speed of a reaction
    e. free energy of activation
    d. speed of a reaction
  33. Zinc, an essential trace element, may be found bound to the active site of some enzymes. What would be the most likely function of such zinc ions?
    a. coenzyme derived from a vitamin
    b. a cofactor necessary for catalysis
    c. a substrate of the enzyme
    d. a competitive inhibitor of the enzyme
    e. an allosteric activator of the enzyme
    b. a cofactor necessary for catalysis
  34. When electrons move closer to a more electronegative atom,
    a. energy is released
    b. energy is consumed
    c. a proton gradient is established
    d. water is produced
    e. ATP is synthesized
    a. energy is released
  35. In the reaction C6H12O6 +6O2 ----> 6CO2 + 6H20
    a. oxygen becomes reduced
    b. glucose becomes reduced
    c. oxygen becomes oxidized
    d. water is a reducing agent
    e. ozygen is a reducing agent
    a. oxygen becomes reduced
  36. Some prokaryotes use anaerobic respiration, a process that
    a. does not involve an electron transport chain
    b. produces ATP soley by substrate-level phosphorylation
    c. uses a substance other than oxygen as the final electron acceptor
    d. does not rely on chemiosmosis for the production of ATP
    e. both a and are correct.
    c. uses a substance other than oxygen as the final electron acceptor
  37. Which of the following is not true of oxidative phosphorylation?
    a. It produces approximately three ATP for every NADH that is oxidized
    b. it involves the redox reactions of the electron transport chain
    c. it involves an ATP synthase located in the inner mitochondrial membrane
    d. it uses oxyfen as the initial electron donor
    e. it is an example of chemiosmosis
    d. it uses oxyfen as the initial electron donor
  38. Substrate-level phosphorylation
    a. involves the shifting of a phosphate group from ATP to a substrate
    b. can use NADH or FADH2
    c.takes place only in the cytosol
    d. accounts for 10% of the ATP formed by fermentation
    e. is the energy source for facultative anaerobes under anaerobic conditions
    e. is the energy source for facultative anaerobes under anaerobic conditions
  39. The major reason that glycolysis is not as energy productive as respiration is that
    a. NAD+ is regenerated by alcohol or lactate production, without the high-energy electrons passing through the electron transport chain
    b. it is the pathway common to fermentation and respiration
    c. it does not take place in a specialized membrane bound organelle
    d. pyruvate still contains much of the energy from glucose
    e. substrate-level phosphorylation is not as energy efficient as oxidative phosphorylation
    d. pyruvate still contains much of the energy from glucose
  40. Which of the following conversions represents a reduction reaction?
    a. pyruvate------> acetyl CoA + CO2
    b. C6H12O6------> 6 CO2
    c. NADH + H+ -----> NAD+ + 2H
    d. glucose ------> pyruvate
    e. acetaldehyde(C2H4O) ----> ethanol (C2H6O)
    e. acetaldehyde(C2H4O) ----> ethanol (C2H6O)
  41. What is the role of oxygen in cellular respiration?
    a. it is reduced in glycolysis as glucose is oxidized.
    b. it provides electrons to the electron transport chain
    c. it provides the activation energy neeeded for oxidation to occur
    d. it is the final electron acceptor for the electron transport chain
    e. it combines with the carbon removed during the citric acid cycle to form CO2.
    d. it is the final electron acceptor for the electron transport chain
  42. When pyruvate is converted to acetyl CoA,
    a. CO2 and ATP are released
    b. a multienzyme complex removes a carboxyl group, transfers electrons to NAD+, and attaches a coenzyme
    c. one turn of the citric acid cycle is completed
    d. NAD+ is regenerated so that glycolysis can continue to produce ATP by substrate-level phosphorylation
    e. phosphofructokinase is activated and glycolysis continues
    b. a multienzyme complex removes a carboxyl group, transfers electrons to NAD+, and attaches a coenzyme
  43. How many molecules of CO2 are generated for each molecule of acetyl CoA introduced into the citric acid cycle?
    a. 1
    b. 2
    c. 3
    d. 4
    e. 6
    b. 2
  44. In the chemiosmotic mechanism,
    a. ATP production is linked to the proton gradient established by the electron transport chain
    b. the difference in pH between the intermemebrane space and the cytosol drives the formation of ATP
    c. the flow of H+ through ATP synthases from the matrix to the intermembrane space drives the phosphorylation of ADP.
    d. the energy released by the reduction and subsequent oxidation of components of the electron transport chain is transferred as a phosphate to ADP
    e. the production of water in the matrix by the reduction of oxygen leads to a net flow of water out of a mitochondrion
    a. ATP production is linked to the proton gradient established by the electron transport chain
  45. Which of the following reactions is incorrectly paired with its location?
    a. ATP Synthesis-inner membrane of the mitochondrion, matrix, cytosol
    b. fermentation-cell cytosol
    c. glycolysis-cell cytosol
    d. substrate-level phosphorylation-cytosol and matrix
    e. citric acid cycle-cristae of mitochondrion
    e. citric acid cycle-cristae of mitochondrion
  46. When glucose is oxidized to Co2 and water, approximately 40% of its energy is transferred to
    a. heat
    b. ATP
    c. acetyl CoA
    d. water
    e. the citric acid cycle
    b. ATP
  47. From an energetic viewpoint, what do muscle cells in oxygen depreivation gain from the reduction of pyruvate?
    a. ATP
    b. ATP and recycled NAD+
    c. CO2 and NAD+
    d. ATP, alcohol, and NAD+
    e. ATP and CO2
    b. ATP and recycled NAD+
  48. Glucose, made from six radioactively labeled carbon atoms, is fed to yeast cells in the absence of oxygen. How many molecules of radioactive alcohol(C2H5OH) are formed from each molecule of glucose?
    a. 0
    b. 1
    c. 2
    d. 3
    e. 6
    c. 2
  49. Which of the following produces the most ATP per gram?
    a. glucose, because it is the starting place for glycolysis
    b. glycogen or starch, because they are polymers of glucose
    c. fats, because they are highly reduced compounds
    d. proteins, because of the energy stored in their tertiary structure
    e. amino acids, because they can be fed directly into the citric acid cycle
    c. fats, because they are highly reduced compounds
  50. Fats and proteins can be used as fuel in the cell because they
    a. can be converted to glucose by enzymes
    b. can be converted to intermediates of glycolysis or the citric acid cycle
    c. can pass through the mitochondrial memebrane to enter the citric acid cycle
    d. contain phosphate groups
    e. contain more energy than glucose
    b. can be converted to intermediates of glycolysis or the citric acid cycle
  51. Which is not true of the enzyme phosphofructokinase? It is
    a. an allosteric enzyme
    b. inhibited by citrate
    c. the pacemaker of glycolysis and respiration
    d. inhibited by ADP
    e. an early enzyme in the glycolytic pathway
    d. inhibited by ADP
  52. Substrate-level phosphorylation accounts for approximately what percentage of ATP formation when glucose is oxidized to CO2 and water?
    a. 0%
    b. 4%
    c. 10%
    d. 15%
    e. 20%
    c. 10%
  53. Cyanide is a poison that blocks the passage of electrons along the electron transport chain. Which of the following is a metabolic effect of this poison?
    a. the pH of the intermemebrane space becomes much lower than normal
    b. Electrons arepassed directly to oxygen, causing cells to explode
    c. Alcohol would build up in the cells.
    d. NADH supplies would be exhausted, and ATP synthesis would cease
    e. No proton gradient would be produced, and ATP synthesis would cease.
    e. No proton gradient would be produced, and ATP synthesis would cease.
  54. Which enzyme would use NAD+ as a coenzyme?
    a.phosphofructokinase
    b. phosphoglucoisomerase
    c. triose phosphate dehydrogenase
    d. hexokinase
    e. phosphoglyceromutase
    c. triose phosphate dehydrogenase
  55. The metabolic function of fermentation is to
    a.oxidize NADH to NAD+ so that glycolysis can continue in the absence of oxygen
    b. reduce NADH so that more ATP can be produced by the electron transport chain
    c. produce lactate during aerobic exercise
    d. oxidize pyruvate, thus releasing more energy
    e. make beer.
    a.oxidize NADH to NAD+ so that glycolysis can continue in the absence of oxygen
  56. Which compound will produce the most ATP when oxidized?
    a. acetyl CoA
    b. glucose
    c. pyruvate
    d. fructose bisphosphate
    e. glyceraldehyde-3-phosphate
    d. fructose bisphosphate
  57. Which of the following is mismatched with its location?
    a. light reactions-grana
    b. electron transport chain- thylakoid membrane
    c. Calvin cycle- stroma
    d. ATP synthase-double membrane surrounding chloroplast
    e. splitting of water- thylakoid space
    d. ATP synthase-double membrane surrounding chloroplast
  58. Photosynthesis is a redox process in which
    a. CO2 is reduced and water is oxidized
    b. NADP+ is reduced and RuBP is oxidized
    c. CO2, NADP+, and water are reduced
    d. O2 acts as an oxidizing agent and water acts as a reducing agent
    e. G3P is reduced and the electron transport chain is oxidized.
    a. CO2 is reduced and water is oxidized
  59. Accessory pigments withing chloroplasts are responsible for
    a. driving the splittinng of water molecules
    b. absorbing photons of different wavelengths of light and passing that energy to P680 or P700.
    c. providing electrons to the reaction-center chlorophyll after photoexcited electrons pass to NADP+.
    d. pumping H+ across the thylakoid membrane to create a proton-motive force
    e. anchoring chlorophyll a within the reaction center
    b. absorbing photons of different wavelengths of light and passing that energy to P680 or P700.
  60. Linear electron flow along with chemiosmosis in the chloroplast results in the production of
    a. ATP only
    b. ATP and NADPH
    c. ATP and G3P
    d. ATP and O2.
    e. ATP, NADPH, and O2
    e. ATP, NADPH, and O2
  61. The chlorphyll known as P680+ has its electron "holes" filled by electrons from
    a. photosystem I
    b. photosystem II
    c. water
    d. NADPH
    e. accessory pigments
    c. water
  62. What are the final electron acceptors for the electron transport chains in the light reactions of photosynthesis and in cellular respiration?
    a. O2 in both
    b. CO2 in both
    c. H20 in the light reactions and O2 in respirtion
    d. H20 in the light reactions and NAD+ or FAD in respiration
    e. NADP+ in the light reactions and O2 in respiration
    e. NADP+ in the light reactions and O2 in respiration
  63. Chloroplasts can make carbohydrate in the dark if provided with
    a. ATP, NADPH, and CO2
    b. an artificially induced proton gradient
    c. organic acids or four carbon compounds
    d. a source of hydrogen
    e. photons and CO2
    a. ATP, NADPH, and CO2
  64. In the chemiosmotic synthesis of ATP in a chloroplast, H+ diffuses throught the ATP synthase
    a. from the stroma into the thylakoid space
    b. from the thylakoid space into the stroma
    c. from the intermembrane space into the matrix
    d. from the cytoplasm into the intermembrane space.
    e. from the matrix into the stroma.
    b. from the thylakoid space into the stroma
  65. A difference between electron transport in photosynthesis and respiration is that in photosynthesis
    a. NADPH rather than NADH passes electrons to the electron transport chain,
    b. ATP synthase releases ATP into the stroma rather than into the cytosol
    c. light provides the energy to push electrons to the top of the electron chain, rather than energy from the oxidation of food molecules
    d. an H+ concentration gradietn rather than a proton-motive force drives the phosphorylation of ATP.
    e. both a and c are correct
    c. light provides the energy to push electrons to the top of the electron chain, rather than energy from the oxidation of food molecules
  66. NADPH and ATP from the light reactions are both needed
    a. in the carbon fixation stage to provide energy and reducing power to rubisco
    b. to regenerate three RuBP from five G3P(glyceraldehyde-3-phosphate).
    c. to combine two molecules of G3P to produce glucose.
    d. to reduce 3-phosphoglycerate to G3P
    e. to reduce the H+ concentration in the stroma and contribute to the proton-motive force.
    d. to reduce 3-phosphoglycerate to G3P
  67. What portion of an illuminated plant cell would you expect to have the lowest pH?
    a. nucleus
    b. cytosol
    c. chloroplast
    d. stroma of chloroplast
    e. thylakoid space
    e. thylakoid space
  68. What does rubsico do?
    a. reduces CO2 to G3P
    b. regenerates RuBP with the aid of ATP
    c. combines electrons and H+ to reduce NADP+ to NADPH
    d. adds CO2 to RuBP in the carbon fixation stage
    e. transfers electrons from NADPH to 1,3-bisphosphoglycerate to produce G3P.
    d. adds CO2 to RuBP in the carbon fixation stage

What would you like to do?

Home > Flashcards > Print Preview