Biochemistry 5th Edition International Edition by Reginald H. Garrett - Test Bank

Chapter 1—The Facts of Life: Chemistry Is the Logic of Biological Phenomena MULTIPLE CHOICE 1. All are distinctive properties of living systems EXCEPT: a. Living organisms are relatively simple. b. Biological structures play a role in the organism's existence. c. The living state is characterized by the flow of energy through the organism. d. Living organisms are highly organized. e. Living organisms are actively engaged in energy transformation. ANS: A PTS: 1 2. Even though the building blocks have fairly simple structures, macromolecules are exquisitely organized in their intricate three-dimensional architecture known as: a. configuration. b. conformation. c. sequence. d. Lewis structure. e. structural maturation. ANS: B PTS: 1 3. All of the following activities require the presence of ATP or NADPH EXCEPT: a. osmoregulation. b. biosynthesis. c. movement of muscles. d. light emission. e. none, they are all energy-requiring activities. ANS: E PTS: 1 4. Which are the four most common elements in the human body? a. hydrogen, calcium, oxygen and sodium b. hydrogen, oxygen, iron and carbon c. hydrogen, oxygen, carbon and nitrogen d. oxygen, carbon, iron and nitrogen e. oxygen, silicon, calcium and nitrogen ANS: C PTS: 1 5. What makes carbon such an abundant element in biomolecules? a. It can form up to five bonds by sharing its electrons. b. It forms only single bonds. c. It provides low bond energy. d. It forms stable covalent bonds by electron pair sharing. e. It does not usually bond to other carbons, allowing a more diverse combination of elements. ANS: D PTS: 1 Garrett/Grisham 5e Test Bank 1 6. The major precursors for the formation of biomolecules include all EXCEPT: a. nitrate and dinitrogen. b. water. c. carbon dioxide. d. ammonium ion. e. none, all are major precursors. ANS: E PTS: 1 7. From the major precursors, the complex biomolecules are made in which sequence? a. metabolites, building blocks, macromolecules, supramolecular complexes b. macromolecules, building blocks, metabolites, supramolecular complexes c. building blocks, macromolecules, supramolecular complexes, metabolites d. metabolites, macromolecules, building blocks, supramolecular complexes e. metabolites, building blocks, supramolecular complexes, macromolecules ANS: A PTS: 1 8. The structural integrity of supramolecular complexes (assemblies) of multiple components are bonded to each other by all of the following forces EXCEPT: a. covalent bonds b. van der Waals forces c. hydrogen bonds d. hydrophobic interactions e. ionic interactions ANS: A PTS: 1 9. Organelles have what three attributes? a. Only in prokaryotic cells, membrane bound, have a dedicated set of tasks. b. Only in eukaryotic cells, membrane bound, have a dedicated set of tasks. c. Only in eukaryotic cells, seldom membrane bound, have a dedicated set of tasks. d. Only in prokaryotic cells, membrane bound, multi-functional. e. In both prokaryotic cells and eukaryotic cells, membrane bound, have a dedicated set of tasks. ANS: B PTS: 1 10. Membrane structures are maintained primarily by: a. hydrophobic interactions. b. covalent bonds. c. hydrogen bonds. d. non-spontaneous assembly. e. ionic interactions. ANS: A PTS: 1 11. All of the following are properties of membranes EXCEPT: a. supramolecular assemblies. b. define boundaries of cellular components. c. spontaneous assemblies resulting from hydrophobic interactions. d. identical protein and lipid composition in the major organelles. e. none, all are true. ANS: D PTS: 1 Garrett/Grisham 5e Test Bank 2 12. Which of the following properly ranks the non-covalent interactions in order of increasing strength? a. ionic, hydrogen bond, van der Waals b. van der Waals, hydrogen bond, ionic c. van der Waals, ionic, hydrogen bond d. hydrogen bond, van der Waals, ionic e. cannot be determined since ionic interactions and hydrogen bonds often vary in strength ANS: E PTS: 1 13. Weak forces that create constantly forming and breaking interactions at physiological temperatures, but cumulatively impart stability to biological structures generated by their collective activity include all EXCEPT: a. hydrogen bonds b. van der Waals forces c. covalent bonds d. ionic interactions e. hydrophobic interactions ANS: C PTS: 1 14. Which of the following is a true statement about non-covalent bonds? a. They are all the result of electron sharing. b. Hydrogen bonds, ionic bond and hydrophobic interactions all carry a degree of specificity while van der Waals interactions are induced. c. All noncovalent bonds are formed between oppositely charged polar functions. d. Van der Waals interactions are not affected by structural complementarity, while hydrogen bonds, ionic bonds and hydrophobic interaction are affected by structural complementarity. e. Hydrogen, van der Waals, and hydrophobic interactions do not form linear bonds. ANS: B PTS: 1 15. Which of the statements about the nature of the hydrogen bond is true? a. The donor is a hydrogen atom bonded to a carbon. b. The more linear the bond, the stronger the interaction. c. The acceptor must be similar in electronegativity to hydrogen. d. It is a type of covalent bond. e. A hydrogen bond is weaker than van der Waals forces. ANS: B PTS: 1 16. Electrostatic forces a. include ionic interactions between negatively charged carboxyl groups and positively charged amino groups. b. average about 2 kJ/mol in aqueous solutions. c. typically are directional like hydrogen bonds. d. require a precise fit like van der Waals interactions. e. include ionic, induced dipole and permanent dipole interactions. ANS: A PTS: 1 Garrett/Grisham 5e Test Bank 3 17. All are true about hydrophobic interactions EXCEPT: a. Hydrophobic interactions result from the strong tendency of water to exclude nonpolar groups or molecules. b. Hydrophobic interactions result because water molecules prefer the stronger interactions that they share with one another, compared to their interactions with nonpolar molecules. c. Hydrophobic interactions result from hydrogen bonds between water and the hydrophobic molecules. d. The preferential interactions between water molecules "exclude" hydrophobic substances from aqueous solution and drive the tendency of nonpolar molecules to cluster together. e. Hydrophobic interactions result in nonpolar regions of biological molecules being buried in the molecule's interior to exclude them from the aqueous milieu. ANS: C PTS: 1 18. Which of the following molecular recognition mechanisms is based upon structural complementarity? a. interaction of a protein with a metabolite. b. the association of a strand of DNA with its complementary strand. c. the ability for a sperm cell to bind to an egg. d. the binding of a hormone to its receptor. e. all of the above ANS: E PTS: 1 19. All of the statements about structural complementarity are true EXCEPT: a. Weak chemical forces mediate it. b. It produces strong irreversible interactions. c. It is the interaction of a biological macromolecule and its ligand. d. It is the basis of many biological functions. e. It is the means of recognition in bimolecular interactions. ANS: B PTS: 1 20. Which of the following statements regarding molecular recognition is correct? a. Covalent bonds are a common interaction used in molecular recognition. b. Molecular recognition takes place only between protein molecules. c. For molecular recognition to occur, complementarity of the molecules is required. d. Hydrogen bonds are not effective mediators of molecular recognition due to their low strength. e. None of the above are correct. ANS: C PTS: 1 21. Biological molecules are functionally active only within a narrow range of environmental conditions with denaturation occurring in all EXCEPT: a. dramatic increase in temperature. b. change in ionic strength. c. refrigeration. d. addition of strong acid or base. e. none, all will denature biological macromolecules. ANS: C PTS: 1 Garrett/Grisham 5e Test Bank 4 22. Which of the following statements about metabolism is true? a. Metabolism only occurs inside of organelles. b. Metabolism is rarely organized into pathways. c. Metabolism always results in a production of ATP. d. Metabolism has two components: anabolism and catabolism. e. Metabolism is characterized by single reactions with large energy releases. ANS: D PTS: 1 23. All of the following functions of an enzyme are true EXCEPT: a. Enzymes help to catalyze virtually every metabolic reaction. b. Enzymes mediate the rates of cellular reaction in proportion to cellular requirements. c. Enzymes are sensitive to temperature, pH, and concentration changes. d. An increased activity of an enzyme increases the amount of energy produced. e. Enzymes are used as a catalyst to increase reaction rates many orders of magnitude. ANS: D PTS: 1 24. All are true for prokaryotic cells EXCEPT: a. Some have flagella. b. They have a simple plasma or cell membrane. c. They posses a distinct nuclear area, but no nucleus. d. They have ribosomes, but no mitochondria. e. All are true. ANS: E PTS: 1 25. Composed of peptidoglycan, a rigid framework of polysaccharide cross-linked by short peptide chains, describes what structural feature of a prokaryotic cell? a. cytosol b. ribosome c. nuclear area d. cell membrane e. cell wall ANS: E PTS: 1 26. All are internal membrane specialized structures of animal cells EXCEPT: a. lysosome. b. nucleus. c. endoplasmic reticulum. d. mitochondria. e. chloroplast. ANS: E PTS: 1 27. Arrays of filaments in eukaryotic cells that give the cell its shape and its capacity to move are called the: a. plasma membrane. b. smooth endoplasmic reticulum. c. cytoskeleton. d. lysosome. e. Golgi body. ANS: C PTS: 1 Garrett/Grisham 5e Test Bank 5 28. Supramolecular complexes of nucleic acid encapsulated in a protein coat, and in some instances, surrounded by a membrane envelope are called: a. viruses. b. plasmids. c. nucleosomes. d. ribosomes. e. all are true. ANS: A PTS: 1 29. Viruses are acellular, but they act as cellular parasites in order to: a. reproduce. b. protect themselves. c. grow in size. d. gain genetic information. e. all are true. ANS: A PTS: 1 30. Rough ER are "studded" with: a. lysosomes. b. ribosomes. c. peroxisomes. d. nucleosomes. e. all are true. ANS: B PTS: 1 31. When viral genetic elements are integrated into the host chromosome and become quiescent, it is referred to as: a. cytolytic. b. lysogeny. c. hemolytic. d. propagational. e. autonomy. ANS: B PTS: 1 32. Which organelle is responsible for the bulk of energy production in the form of ATP? a. chloroplast b. mitochondria c. golgi apparatus ANS: B d. lysosome e. endoplasmic reticulum PTS: 1 33. A carboxylic acid at pH 7.4 would most likely form a(n) ___________ with a(n) ____________. a. b. c. ionic interaction / amine ionic interaction / ketone hydrogen bond / alcohol d. hydrogen bond / aldehyde e. both a and c are correct ANS: E PTS: 1 Garrett/Grisham 5e Test Bank 6 34. Which of the following molecules is not generally incorporated into macromolecules? a. amino acids b. monosaccharides c. nucleotides ANS: D d. fatty acids e. all of the above are incorporated into macromolecules Garrett/Grisham 5e Test Bank 7 PTS: 1 Chapter 2—Water: The Medium of Life MULTIPLE CHOICE 1. Properties of water that render it so suited to its role as a medium of life include all EXCEPT: a. Unrivaled ability to form hydrogen bonds. b. Unusually high dielectric constant of water explains water's ability to surround ions and increase the ions' attraction for one another. c. Unparalleled ability to orient around nonpolar solutes to promote hydrophobic interactions. d. The small, but significant, tendency to form H+ and OH ions. e. None, all are true. ANS: B PTS: 1 2. All are true for water for a substance of its molecular weight that is neither metallic nor ionic EXCEPT: a. a high surface tension. b. a chemically inert solvent, which has a great capacity to dissolve a diverse spectrum of molecules and ions. c. a positive volume of melting. d. a high dielectric constant. e. a high capacity to form hydrogen bonds ANS: C PTS: 1 3. The unrivaled ability to form ____ hydrogen bonds per liquid water molecule is the source of the strong intermolecular attractions unique to water. a. 1 b. 2 c. 3 d. 4 e. 5 ANS: D PTS: 1 4. Because of its highly polar nature, water is an excellent solvent for polar substances, but NOT for: a. salts. b. sugars. c. aldehydes and ketones. d. hydrocarbons. e. alcohols and amines. ANS: D PTS: 1 5. The solvent with the highest dielectric constant in this group is: a. water. b. acetic acid. c. ethanol. d. hexane. e. benzene. ANS: A PTS: 1 Garrett/Grisham 5e Test Bank 1 6. Hydrogen bonds in ice are all EXCEPT: a. directional. b. straight. c. weak. d. responsible for the lower density of ice over liquid water. e. holding water molecules in ice apart. ANS: C PTS: 1 7. Pure liquid water consists of H2O molecules: a. held in a rigid three-dimentional network. b. with local preference for linear geometry. c. with large numbers of strained or broken hydrogen bonds. d. which do not switch H-bonds readily. e. all are true. ANS: C PTS: 1 8. The average lifetime of a hydrogen bond connection in water is on the order of 10: a. picoseconds. b. microseconds. c. milliseconds. d. seconds. e. nanoseconds. ANS: A PTS: 1 9. The ____ bonding of water with the polar functional groups on nonionic polar solutes such as sugars are ____ than the intermolecular attractions between solute molecules allowing solute molecules to readily dissolve in water. a. ionic, stronger b. hydrogen, weaker c. hydrophobic, stronger d. hydrogen, stronger e. ionic, weaker ANS: D PTS: 1 10. The H-bonded water around an ionic substance tends to ____; and the H-bonded water around nonpolar solutes tends to ____. a. inhibit ionization, promote hydrophobic interactions b. inhibit ionization, inhibit hydrophobic interactions c. not impact ionization, inhibit hydrophobic interactions d. promote ionization, not impact hydrophobic interactions e. promote ionization, promote hydrophobic interactions ANS: E PTS: 1 11. Amphiphilic (amphipathic) molecules include: a. sugars. b. acidic amino acids. c. inorganic salts. d. water. e. salts of fatty acids. ANS: E PTS: 1 Garrett/Grisham 5e Test Bank 2 12. In micelles: a. polar ends form hydrophobic interactions with water. b. nonpolar ends form hydrophilic interactions with water. c. hydrocarbon tails form hydrophobic interactions with water. d. polar ends are hydrophobic and nonpolar ends are hydrophilic. e. hydrocarbon tails are excluded from the water into hydrophobic domains. ANS: E PTS: 1 13. By limiting the orientation that neighboring water molecules can assume, solutes give ____ to the solvent and ____ the dynamic interplay among H2O molecules that occurs in pure water. a. pressure, disrupt b. disorder, increase c. disorder, decrease d. order, diminish e. order, increase ANS: D PTS: 1 14. To ____ the osmotic pressure created by the contents of their cytosol, cells tend to store substances such as amino acids and sugars in ____ form. a. increase, monomeric b. minimize, polymeric c. minimize, monomeric d. maximize, polymeric e. increase, polymeric ANS: B PTS: 1 15. Water ionizes because: a. the smaller electronegative oxygen atom strips the electron from one of its hydrogen atoms, leaving the proton to dissociate. b. the larger electronegative oxygen atom strips the electron from one of its hydrogen atoms, leaving the proton to dissociate. c. the smaller electropositive oxygen atom strips the electron from one of its hydrogen atoms, leaving the proton to dissociate. d. the larger electropositive oxygen atom strips the electron from one of its hydrogen atoms, leaving the proton to dissociate. e. None of the above ANS: B PTS: 1 16. Grapefruit juice at pH 3.2 contains about ____ times as much H+ as orange juice at pH 4.3. a. 0.9 b. 107.5 c. 102 d. 12 e. 101 ANS: D PTS: 1 Garrett/Grisham 5e Test Bank 3 17. All are examples of weak electrolytes EXCEPT: a. hydrochloric acid. b. acetic acid. c. lactic acid. d. phosphoric acid. e. carbonic acid. ANS: A 18. If 0.1 moles of Na2HPO4 and 0.1 moles of NaH2PO4 are mixed in water, what is the resulting pH? The pKa values for phosphoric acid are 2.1, 7.2, 12.4. a. 2.1 b. 4.65 c. 7.2 d. 9.8 e. 12.4 ANS: C 19. Estimate the pH of the resulting solution prepared by mixing 1.0 mole of solid disodium phosphate (Na2HPO4) and 1.25 mole of hydrochloric acid. The pKa values for phosphoric acid are 2.1, 7.2, 12.4. a. pH<2.1 b. pH=2.1 c. 2.1<pH<7.2 d. pH=7.2 e. 7.2<pH<12.4 ANS: C PTS: 1 PTS: 1 PTS: 1 20. Which of the following pairs would be the best buffer at pH 10.0? a. Acetic acid and sodium acetate (pKa = 4.76) b. H2CO3 and NaHCO3 (pKa values are 3.77 and 10.4) c. Lactic acid and sodium lactate (pKa = 3.86) d. NaH2PO4 and Na2HPO4 (pKa values are 2.1, 7.2, 12.4) e. Sodium succinate and succinic acid (pKa = 4.21) ANS: B PTS: 1 21. What ionic form(s) is/are most prevalent at pH 7.0? The pKa values of phosphoric acid are 2.1, 7.2, 12.4. 2 b. H2PO4 a. HPO4 c. HPO4 d. H2PO4 e. All are correct 2  3 and HPO4 and PO4 2 ANS: B 22. A plasma pH of 6.8 doesn't seem too far away from a normal pH of 7.4, but at pH 6.8 the H+ concentration is ____ times greater than at pH 7.4 and results in severe acidosis. a. 0.1 b. 0.6 c. 4 d. 10 e. 20 ANS: C 23. pH = pKa when: PTS: 1 a. [A]/[HA] = 0 b. log ([A]/[HA]) = 1 Garrett/Grisham 5e Test Bank 4 PTS: 1 c. [A] >> [HA] d. [A] = [HA] e. log ([HA]/[A]) = 1 ANS: D PTS: 1 24. Buffers have all of the following characteristics EXCEPT: a. they have relatively flat titration curves at the pH(s) where they buffer. b. they resist changes in their pH as acid or base is added. c. they are typically composed of a weak acid and its conjugate base. d. they buffer best for polyprotic acids half-way between the two pKa values. e. buffer where the amounts of conjugate base are nearly equivalent to the amounts of weak acid. ANS: D PTS: 1 25. Buffer systems are effective when the pH values are within ____ pH unit(s) of the pKa value. a. 1 b. 2 c. 3 d. 4 e. 5 ANS: A PTS: 1 26. Intracellular pH is maintained primarily by the ____ and ____ buffer systems, and the extracellular pH by the ____ buffer system. 2   a. HPO4 /H2PO4 ; HCO3 /H2CO3; histidine b. H3PO4/H2PO4; histidine; HCO3/H2CO3 c. HCO3/H2CO3; H3PO4/H2PO4; histidine 2  d. HPO4 /H2PO4 ; histidine; HCO3 /H2CO3 e. HCO3/H2CO3; histidine; H3PO4/H2PO4 ANS: D PTS: 1 27. Hyperventilation is a physiological mechanism to: a. lower [CO2 (g)] in the blood and increase blood pH. b. raise [CO2 (g)] in the blood and increase blood pH. c. lower [CO2 (g)] in the blood and decrease blood pH. d. raise [CO2 (g)] in the blood and decrease blood pH. e. lower [CO2 (g)] in the blood and increase [HCO3]. ANS: A PTS: 1 Garrett/Grisham 5e Test Bank 5 28. Water is particularly suited as a solvent for biosystems because it has all of the following characteristics EXCEPT: a. Water is a medium for ionization enhancing the variety of chemical species. b. Water is innocuous, yet a powerful solvent. c. Water is an excellent solvent for nonpolar substances. d. Water is relatively chemically inert, yet dissolves a variety of solutes. e. Through hydrophobic interactions, lipids coalesce into membranes in water. ANS: C PTS: 1 29. Which of the following weak acids would make the best buffer at pH = 5.0? 5 a. acetic acid (Ka = 1.74  10 , pKa = 4.76) 7 b. H2PO4 (Ka = 1.38  10 , pKa = 7.20) 11 4 e. lactic acid (Ka = 1.38  10 , pKa = 3.86) ANS: A PTS: 1 30. The enzyme fumarase has a pH optimum of about 7.6. What would be the buffer of choice to study this enzyme? 4 a. lactic acid (Ka = 1.38  10 , pKa = 3.86) ANS: E PTS: 1 31. When preparing an acetate buffer at pH 4.5 with 0.01 M solutions of acetic acid (pKa = 4.8) and sodium acetate, the volume of acetic acid needed would be ____ the volume of sodium acetate solution. a. equal to b. less than half of c. more than half of d. about six times e. about twice ANS: E 32. Hypoventilation is characterized by inability to excrete CO2 rapidly enough and can be caused by all EXCEPT: a. anesthetics. b. depressant drugs. c. narcotics. d. lung diseases. e. encephalitis. ANS: E 33. If an abundance of an organic acid with a pKa of 3.9 is found in the bloodstream, which of the following is true? a. it will be mostly protonated b. it will be mostly deprotonated c. it will form an effective buffer d. it will cause metabolic acidosis e. both b and d are correct ANS: E PTS: 1 c. bicarbonate (Ka = 6.3  10 d. tris-hydroxymethyl aminomethane (Ka = 8.32  10 , pKa = 8.07) b. bicarbonate (Ka = 6.3  10 c. acetic acid (Ka = 1.74  10 , pKa = 4.76) , pKa = 10.24) d. succinate (Ka = 2.34  10 , pKa = 5.63) Garrett/Grisham 5e Test Bank 6 PTS: 1 PTS: 1 11 5 , pKa = 10.24) 6 e. tris-hydroxymethyl aminomethane (Ka = 8.32  10 , pKa = 8.07) 9 9 34. Aspirin contains a carboxylic acid with a pKa of 3.5. Which of the following is true? a. Aspirin will be mostly protonated in the stomach b. Aspirin will be mostly protonated in the bloodstream c. Aspirin will be easily absorbed in the stomach due to its negative charge d. Aspirin will be easily transported in the bloodstream due to its negative charge e. both a and d are correct ANS: E PTS: 1 35. If a. b. c. d. e. a weak acid is 25% deprotonated at pH 4, what would the pKa be? 3.40 3.52 4.48 4.60 cannot determine from given information ANS: C PTS: 1 36. Which of the following would be the conjugate acid of hydrogen phosphate, HPO4 -2 ? a. H2PO4- b. H3PO4 d. H2PO4- e. none of the above c. H2PO4 -2 ANS: A 37. Formic acid is the active agent in an ant bite. What is the ratio of base/acid for formic acid (pKa = 3.9) in the blood stream at pH 7.4? a. 3.16  10-4 b. 3.16  103 c. 0.54 d. 1.90 e. cannot be determined based upon the provided information PTS: 1 ANS: B 38. Which of the following statements is INCORRECT about the nature of the hydrogen bond PTS: 1 a. The donor is a hydrogen atom bonded to an atom that is less electronegative than hydrogen. b. The more linear the bond, the stronger the interaction. c. The acceptor is a fairly electronegative atom containing a nonbonding pair of electrons. ANS: A PTS: 1 d. It is a type of noncovalent bond. e. All of the above statements are true about the nature of the hydrogen bond Garrett/Grisham 5e Test Bank 7 39. A weak acid is 33% dissociated at pH 5.0. What is the pKa for this acid? a. 4.5 b. 4.7 c. 5.3 ANS: C d. 5.5 e. cannot be determined from the information provided Garrett/Grisham 5e Test Bank 8 PTS: 1 biochemistry - test banks, biochemistry test banks, biochemistry test examples, biochemistry test rate, biochemistry test charges, biochemistry test answer key,