Skip to content
Exam Guides

Biochemistry Eighth Edition Test Bank

Develop strong exam strategies with Biochemistry Eighth Edition Test Bank, a trusted guide packed with expert insights and sample problems.

Preview 16 of 412 pages

See the first 16 pages exactly as they appear in the document.

  1. Page 1
    Read page 1 as text

    Chapter 1 Biochemistry: An Evolving Science Multiple - Choice Questions 1) DNA is made from the building blocks adenine, guanine, cytosine and _____. A) uridine B) thymine C) inosine D) ribose E) None of the answers is correct. Answer: B Section: 1.2 2) The DNA backbone is made from repeating _____. A) monosaccharide units B) amino acid units C) sugar - phosphate units D) fatty acid E) None of the answers is correct. Answer: C Section: 1.2 3) The number of hydrogen bonds formed between A and T is _____. A) 1 B) 2 C) 3 D) 4 E) 2 if in DNA, 3 if in RNA Answer: B Section: 1.2 4) The number of hydrogen bonds formed between G and C is _____.

  2. Page 2
  3. Page 3
    Read page 3 as text

    A) 1 B) 2 C) 3 D) 4 E) 2 if in RNA, 3 if in DNA Answer: C Section: 1.2 5) The fundamental groups of organisms include Eukarya, Bacteria , and _____. A) Plantae B) Animalia C) Protista D) Archaea E) Fungi Answer: D Section: 1.1 6) Which of the following are the strongest bonds in molecules? A) covalent bonds B) ionic bonds C) hydrogen bonds D) metallic bonds E) None of the answers is correct. Answer: A Section: 1.1 7) Which of the following describes the relationship between the strengths of hydrogen and covalent bonds? A) H ydrogen bonds are always stronger than covalent bonds . B) H ydrogen bonds and covalent bonds have equivalent strength .

  4. Page 4
    Read page 4 as text

    C) H ydrogen bonds are always weaker than covalent bonds . D) W ith a few exceptions, most hydrogen bonds are stronger than covalent bonds . E) W ith a few exceptions, most covalent bonds are stronger than hydrogen bonds . Answer: C Section: 1.3 8) The matter within a defined region of space is referred to as the _____. A) universe B) system C) outer space D) wormhole E) None of the answers is correct. Answer: B Section: 1.3 9) For a spontaneous reaction, t he  G must be _____. A) positive B) negative C) greater than 1 D) between 1 and 0 E) 0 Answer: B Section: 1.3 10) The term _____ is used to indicate Gibbs free energy. A)  H B)  E C)  S D)  G E)  T

  5. Page 5
    Read page 5 as text

    Answer: D Section: 1.3 11 ) Which of the following is considered a metabolite, a substance that is chemically transformed in a biochemical process? A) deoxyribonucleic acid B) glycerol C) protein D) ribonucleic acid E) polysaccharide Ans: B Section: 1.1 12 ) The structure of DNA described by Watson and Crick included A) a double helix. B) the sugar phosphate backbone aligned in the center of the helix. C) the base pairs that are stacked on the inside of the double helix. D) both a double helix and the sugar phosphate backbone aligned in the center of the helix E) a double helix and the base pairs that are stacked on the inside of the double helix Ans: E Section: 1.2 13 ) What did Watson and Crick suggest to be significant about the base pairing found in the helix? A) It allowed the DNA to twist in a helix. B) The DNA could be circular. C) It was a mechanism for copying. D) All of the a nswers are correct . E) None of the a nswers is correct . Ans: C Section: 1.3

  6. Page 6
    Read page 6 as text

    14 ) Approximately what percentage of the human genome encodes proteins? A) 50% B) 90% C) 20% D) 3% E) None of the answers is correct. Ans: D Section: 1.4 15 ) What gives proteins such a dominant role in biochemistry? A) the rigidity of the peptide backbone B) the ability to act as a blueprint C) the ability to self - replicate D) the ability to spontaneously fold into complex three - dimensional structures E) All of the a nswers are correct . Ans: D Section: 1.4 16 ) If the whole chain is used in a nonoverlapping frame, how many amino acids are defined by this DNA sequence: ATGTTTGGACTA? A) two B) three C) four D) six E) twelve Ans: C Section: 1.4 17 ) What is the [H + ] concentration in a urine sample that has a pH of 6? A) 10 – 6 M B) 10 – 8 M C) 10 6 M D) 10 – 14 M E) 6 M Ans: A Section 1.3 18 ) Which is the correct order of decreasing bond strengths?

  7. Page 7
    Read page 7 as text

    A) hydrogen bonds, covalent bonds, van der Waals interactions B) hydrogen bonds, electrostatic interactions, covalent bonds C) van der Waals interactions, covalent bonds, hydrogen bonds D) covalent bonds, hydrogen bonds, van der Waals interactions E) hydrophobic interactions, hydrogen bonds, electrostatic interactions Ans: D Section: 1.3 19 ) The energies for hydrogen bonds are approximately A) 400 kJ mol – 1 . B) 100 – 240 kJ mol – 1 . C) 4 – 20 kJ mol – 1 . D) 200 kJ mol – 1 . E) None of the a nswers is correct . Ans: C Section: 1.3 20 ) Which of the following is a hydrogen bond donor? A) the N in N — H D B) the H in S — H C) the O in P — O D) the H in O — H E) None of the a nswers is correct . Ans: D Section: 1.3 21 ) Typical van der Waals energies are about A) 4 – 20 kJ mol – 1 . B) 2 – 4 kJ mol – 1 . C) 200 kJ mol – 1 . D) 500 – 1000 kJ mol – 1 . E) None of the a nswers is correct .

  8. Page 8
    Read page 8 as text

    Ans: B Section: 1.3 22 ) What two properties of water are important for biological interactions? A) the polarity of water B) the density of water C) the cohesive properties of water D) the polarity of water and the cohesive properties of water E) the density of water and the cohesive properties of water Ans: D Section: 1.3 23 ) The First Law of Thermodynamics states A) diversity is the result of gradual evolution. B) the total entropy of a system and its surroundings always increase s for a spontaneous process. C) the total energy of a system and its surroundings is constant. D) light is both particle and wave. E) None of the answers is correct . Ans: C Section: 1.3 24 ) The Second Law of Thermodynamics states A) the total entropy of a system and its surroundings alw ays increases for a spontaneous process. B) temperatures will always decrease in a spontaneous process. C) the total energy of a system and its surroundings is constant. D) diversity is the result of gradual evolution. E) None of the a nswers is correct . Ans: A Section: 1.3 25 ) Which of the following atoms commonly found in biological molecules are often hydrogen - bond acceptors ?

  9. Page 9
    Read page 9 as text

    A) carbon B) oxygen C) nitrogen D) All of the answers are correct. E) oxygen and nitrogen Ans: E Section: 1.3 26 ) Entropy is defined as A) a spontaneous reaction. B) the enthalpy of the system. C) the measure of randomness of a system. D) the amount of heat exchanged. E) None of the a nswers is correct . Ans: C Section: 1.3 27 ) If a particular reaction has a negative  G , is it likely to occur? A) Not unless energy is added to the system B) Yes, if it is coupled to another reaction C) Yes, it is spontaneous. D) No, it is not spontaneous. E) Yes, as long as the temperature increases Ans: C Section: 1.3 28 ) What happens to nonpolar molecules in water? A) They dissolve independently. B) They aggregate together. C) They precipitate. D) All of the a nswers are correct . E) None of the a nswers is correct .

  10. Page 10
    Read page 10 as text

    Ans: B Section: 1.3 29 ) What is the [A – ]/[ HA] ratio when a weak acid is in a solution one pH unit below its p K a ? A) 1:1 B) 1:10 C) 10:1 D) 2:1 E) None of the a nswers is correct . Ans: B Section 1.3 30 ) Why does DNA denature when the pH is raised above 9? A) Protons dissociate from guanine bases disrupting the hydrogen bonding to the other strand. B) Protons bind to guanine residues giving them additional positive charges which disrupt the hydrogen bonding to the other strand. C) Protons bind to functional groups that serve as hydrogen - bond acceptors, thus disrupting the hydrogen bonding to the other strand. D) Protons dissociate from the phosphate groups in the backbone, which disrupts the hydrogen - bonding pattern between strands. E) None of the a nswers is correct . Ans: A Section 1.3 31 ) The simplest way to depict stereochemistry is to use A) ball - and - stick models. B) ribbon diagrams. C) space - filling models. D) Fisher projections. E) None of the a nswers is correct . Ans: D Section: Appendix

  11. Page 11
    Read page 11 as text

    32 ) Using the Henderson – Hasselba l ch equation, calculate the pH of a buffer solution made from 0.20 M CH 3 COO H and 0.050 M CH 3 COO – that has p K a = 4.7. A) 5.3 B) 4.1 C) 2.5 D) 0.4 E) None of the a nswers is correct . Ans: B Section 1.3 33 ) What are the primary chemical components present in a phosphate buffer at pH 7.4? A) H 3 PO 4 and PO 4 3 – B) H 2 PO 4 – and PO 4 3 – C) HPO 4 2 – and PO 4 3 – D) H 2 PO 4 – and HPO 4 2 – E) H 3 PO 4 and HPO 4 2 – Ans : D Section 1.3 Short - Answer Questions 3 4 ) What are some of the medical implications of the human genome project? Ans: The obvious use is in diagnosing disease and in developing methods to treat and cure diseases. Physicians will be able to account for individual genetic differences in determining the best medical treatment. Other answers may be correct. Section: Introduction 3 5 ) What is the significance of hydrogen bonding in biochemical structures such as DNA? Ans: The bonds are weak enough to be easily disrupted; yet when many are present, they provide the stabilization necessary for larger structures such as DNA. Section: 1.2 3 6 ) Describe resonance structures. Ans: Resonance structures are ways of writing covalent bonds in which two or more alternate bonding patterns can be achieved. This is due to the sharing of electrons over several atoms.

  12. Page 12
    Read page 12 as text

    Common examples are found in peptide bonds, and in some of the DNA/RNA bases. Adeni ne is shown in the text. Section: 1.3 3 7 ) What is significant about the fact that metabolic processes are common to many organisms? Ans: These metabolic processes are extremely old, geologically, originating in a common ancestor. Section: 1.1 3 8 ) How is water able to be a solvent for so many biological molecules? Ans: Many biological molecules have polar characteristics. Water is extremely polar and is capable of competing with other polar molecules by weakening their electrostatic and hydrogen bonds. The oxygen atom can act as a hydrogen - bond acceptor, and the hydrogen can act as a donor. Section: 1.3 3 9 ) What is the net effect of many van der Waals interactions? Ans: At the interface of two large molecules, the numerous van der Waals interactions can substantially affect and stabilize the interaction. Section: 1.3 40 ) If most proteins are found surrounded by water in the cell, what type of functional groups would you expect to find on the surface of a water - soluble protein? Ans: Polar and charged amino - acid residues would be present on the surface of the protein. Section: 1.3 4 1 ) How are electrostatic forces used in protein folding? Ans: The attraction of two oppositely charged functional groups would be one of the forces helping to form the three - dimensional shape of the protein. Section: 1.3 4 2 ) If the First Law of Thermodynamics is true, how can biological processes be carried out? Ans: Although energy cannot be created or destroyed, it can take on different forms, such as heat or chemical energy. Thus, the energy can be stored as chemical bond energy, which can be used to do work. Section: 1.3 4 3 ) How can a cell exist if the Second Law of Thermodynamics is true?

  13. Page 13
    Read page 13 as text

    Ans: Entropy in a local area can be decreased, but only at the expense of increased entropy in the larger area, or universe. Section: 1.3 4 4 ) Provide a simple example of a process in which the entropy of a system changes. Ans: Several examples can be provided, including the random mixture of atoms when two different gases are mixed, or the creation of water molecules from energy gained following the mixture of oxygen and hydrogen under certain conditions. Section: 1.3 4 5 ) When solutions containing complementary single strands of DNA are mixed, a loss of entropy occurs. How is it that the Second Law of Thermodynamics is not violated? Ans: Heat must be released to the surroundings. Section: 1.3 4 6 ) What is the significance of using  G in biochemistry? Ans: Gibbs free energy, also called the free - energy change, is used to describe the energetics of a reaction. This symbol is used to determine if particular reactions will be spontaneous or biologically feasible. Section: 1.3 4 7 ) What thermodynamic and free - energy changes participate in protein folding? Ans: A combination of hydrogen bonds and van der Waals forces affect enthalpy and the entropy associated with hydrophobic interactions. Section: 1.3 4 8 ) How do hydrophobic interactions aid in protein folding? Ans: Hydrophobic interaction s cause some nonpolar amino acids to aggregate and form the interior of the protein. This results in a net release of heat and a favorable change in the system enthalpy. Section: 1.4 4 9 ) What are the enthalpy and entropy changes that accompany the formation of DNA double heli c es from complementary single strands of DNA? Ans: There is a loss of entropy from the system because there are fewer degrees of freedom in the double helix as compared to the single strands. Therefore, heat must be released when the two strands combine to form the double helix so as not to violate the Second Law of Thermodynamics. Section: 1.3

  14. Page 14
    Read page 14 as text

    50 ) Describe the shape of methane. Ans: Methane is tetrahedral , with bond angles of about 109 ° . Section: Appendix

  15. Page 15
    Read page 15 as text

    Chapter 2 Protein Composition and Structure 1) Which of the following is most often found in proteins? A) D - amino acids B) L - amino acids C) an equal amount of D - and L - amino acids D) amino acids with the  - carbon exclusively having an R absolute configuration E) amino acids with the  - carbon exclusively having an S absolute configuration Answer: B Section: 2.1 2) A term that describes a molecule that contains both positive and negative charges but overall has a neutral charge is _____. A) enantiomer B) amino acid C) racemate D) zwitterion E) amphipath Answer: D Section: 2.1 3) Which amino acid forms disulfide bonds? A) histidine B) methionine C) proline D) serine E) cysteine Answer: E Section: 2.1

  16. Page 16
    Read page 16 as text

    4) Which of the following amino acids has an ionizable R - group with a p K a near neutral pH? A) histidine B) serine C) aspartic acid D) lysine E) tyrosine Answer: A Section: 2.1 5) Formation of a peptide bond produces _____ as a byproduct. A) ammonia B) carbon dioxide C) water D) H + E) OH – Answer: C Section: 2.2 6) What type of plot allows one to investigate the likely phi and psi angles of the peptide backbone? A) Hill B) Lineweaver - Burk C) Hanes - Woolf D) Ramachandran E) Michaelis - Menten Answer: D Section: 2.2 7) What level of protein structure is composed of  helices,  sheets , and turns?

396 more pages in the full document

Unlock it once and it stays in your library, ready to chat with or turn into flashcards.

Unlock the full document

More Biochemistry study materials

See all

Study this document with CramX

Once it is in your library, every tool can work from it.