Chemical Bonding Test 2

25 Questions | Total Attempts: 89

SettingsSettingsSettings
Please wait...
Chemical Bonding Test 2

.


Questions and Answers
  • 1. 
    A nucleoside is a:
    • A. 

      Sugar + base

    • B. 

      Sugar + base + phosphate group

    • C. 

      Sugar + acid

    • D. 

      DNA + base

    • E. 

      RNA + sugar

  • 2. 
    DNA rich in which of the following base pairs has the highest melting temperature (TM)?
    • A. 

      A:U

    • B. 

      A:T

    • C. 

      G:C

    • D. 

      G:A

    • E. 

      G:T

  • 3. 
    In the peptide backbone, there is no rotation around ______ due to its partial double bond character
    • A. 

      N - N bond

    • B. 

      C - C bond

    • C. 

      C - N bond

    • D. 

      C - H bond

    • E. 

      N - H bond

  • 4. 
    In the peptide backbone, rotations around the N - C alpha and C alpha - C bonds are restricted by
    • A. 

      Ionic bonding

    • B. 

      Van der Waals interaction

    • C. 

      H-bonding

    • D. 

      Steric interactions

    • E. 

      None of the rest

  • 5. 
    You have a short piece of synthetic RNA that you want to use as a probe to identify a gene in a sample of DNA. The RNA probe has a tendency to hybridize with sequences that are only weakly complementary. Which of the following statement is correct?
    • A. 

      You should increase the temperature to improve your chances of tagging the correct sequence

    • B. 

      You should decrease the temperature to improve your chances of tagging the correct sequence

    • C. 

      Decreasing the temperature will melt out imperfect matches between the probe and the DNA

    • D. 

      Increase the temperature will increase the chance of tagging the wrong sequence

    • E. 

      None of the rest

  • 6. 
    A portion of the nucleotide sequence from the DNA coding strand of the chick ovalbumin gene is shown here. CTCAGAGTTCACC ATG GGC TCC ATC GGT GCA G- CA AGC ATG GAA -(149bp)-A TTC TTT GGC AGA TGT- GTTTCCCCTTAAAAAGAA What is the partial amino acid sequence of the encoded protein?
    • A. 

      MGSIGAASME-(50 a.a.)-FFGRCVSP

    • B. 

      MSGIAAGSME-(50 a.a.)-EEGRCVSP

    • C. 

      MAASMEGSIG-(50 a.a.)-FFGRCVSP

    • D. 

      MGSIGAASME-(50 a.a.)-RCVSFFGP

    • E. 

      MAASMEGSIG-(50 a.a.)-FCVSFGRP

  • 7. 
    The genome of the bacterium Carsonella ruddii contains 159 kb of DNA with 182 ORFs. What can you conclude about the habitat or lifestyle of this bacterium?
    • A. 

      C ruddii with such a small genome and only 182 genes, must be some sort of parasite rather than a free-living bacterium

    • B. 

      C ruddii with such a small genome and only 182 genes, must be an aerobic organism rather than anaerobic organism

    • C. 

      C ruddii with such a small genome and only 182 genes, must be a thermophilic organism

    • D. 

      C ruddii with such a small genome and only 182 genes, must be a species of plant

    • E. 

      None of the rest

  • 8. 
    Which of the following statements is correct about PCR experiments using DNA polymerase from E. coli instead of from thermophilic bacteria?
    • A. 

      DNA polymerase is destroyed by the high temperature required for separating the double stranded DNA

    • B. 

      After separating the two DNA strands and allowing the primers to anneal with the template, more DNA polymerase has to be added

    • C. 

      The best temperature for primer extension is between 37 - 47 degree celsius

    • D. 

      Fresh DNA polymerase has to be added at each reaction cycle

    • E. 

      All of the rest are correct

  • 9. 
    For amino acids His, Phe, Ser, Ile, Asp and Trp, the correct order of solubility from high to low in water at pH 6.5 is
    • A. 

      Asp, His, Ser, Trp, Ile, Phe

    • B. 

      Phe, Ile, Trp, Ser, His, Asp

    • C. 

      Ser, Asp, His, Ile, Trp, Phe

    • D. 

      Ser, Asp, His, Trp, Ile, Phe

    • E. 

      His, Ser, His, Trp, Ile, Phe

  • 10. 
    Which of the following two amino acid side chains can interact with one another via ion pair at certain pH
    • A. 

      K and E

    • B. 

      K and D

    • C. 

      R and E

    • D. 

      H and D

    • E. 

      All of the rest

  • 11. 
    Glutathione transferase consists of a dimer of two identical subunits. The dimer is in equilibrium with its constituent monomers. Site-directed mutagenesis studies were carried out on this protein in which two arginine residues were mutated to glutamines and two aspartates were mutated to asparagines. These substitutions caused the equilibrium to shift in favour of the monomeric form of the enzyme. Which of the following statements is correct about these arginines and aspartates?
    • A. 

      They are likely to be found on the surface of the monomer forming intra-monomer ion pairs

    • B. 

      They are likely to be found on the surface of the monomer forming inter-monomer ion pairs

    • C. 

      They are likely to be found buried at the core of the monomer

    • D. 

      They are likely to be found on alpha helices

    • E. 

      None of the rest

  • 12. 
    The sequence of crinia-angiotensin, an angiotensin II-like undecapeptide from the skin of the Australian frog is Ala-Pro-Gly-Asp-Arg-Ile-Tyr-Val-His-Pro-Phe. Treatment of the peptide with chymotrypsin released two fragments. Which of the following correspond to the sequence of one of these two fragments.
    • A. 

      APGDRIY

    • B. 

      VHPP

    • C. 

      APGDR

    • D. 

      IYVHPF

    • E. 

      PGDRI

  • 13. 
    The isoelectric point of His is
    • A. 

      7.68

    • B. 

      5.56

    • C. 

      3.82

    • D. 

      7.0

    • E. 

      6.0

  • 14. 
    The isoelectric point of His-Asp is
    • A. 

      4.97

    • B. 

      2.94

    • C. 

      7.68

    • D. 

      4.01

    • E. 

      6.61

  • 15. 
    The isoelectric point of Ala-His-Asp-Arg-Val-Gln is
    • A. 

      7.95

    • B. 

      11.17

    • C. 

      4.97

    • D. 

      7.0

    • E. 

      3.03

  • 16. 
    To make a phosphate buffer at pH 9.6 starting with one liter of 10 mM phosphoric acid (H3PO4; pKs are of 2.15, 6.82, and 12.38), you could add
    • A. 

      5 millimoles of HCL

    • B. 

      15 millimoles of KOH

    • C. 

      25 millimoles of HCL

    • D. 

      20 millimoles of KOH

    • E. 

      You can't make a buffer by adding HCL or KOH

  • 17. 
    To make an acetate buffer at pH 4.76 (pK = 4.76) starting with 500 mL of 0.2 M acetic acid (pK = 4.76), you could add:
    • A. 

      0.05 moles of HCL

    • B. 

      0.025 moles of NaOH

    • C. 

      You can't make a buffer by adding HCL or NaOH

    • D. 

      0.05 moles of NaOH

    • E. 

      0.2 moles of HCL

  • 18. 
    A soccer coach keeps a couple of instant cold packs in her bag in case one of her players suffers a muscle injury. Instant cold packs are composed of a plastic bag containing a smaller water bag and solid ammonium nitrate. In order to activate the fold pack, the bag is kneaded until the smaller water bag breaks, which allows the released water to dissolve the ammonium nitrate. Which of the following statements about the dissolution of ammonium nitrate in water is correct?
    • A. 

      Delta G > 0

    • B. 

      Delta S > 0

    • C. 

      Delta H < 0

    • D. 

      Delta T > 0

    • E. 

      Delta H < Delta S

  • 19. 
    Given the Henderson-Hasselbalch equation as pH = pK + log {[A-] /[HA]}, what is the probability of finding the form of histidine shown in Figure 4 at pH 4 assuming the various pK's of histidine are:      pK amino = 10.0; pK carboxyl = 2.0; pK imidazole = 6.0
    • A. 

      (1/1000001)x(1/101)x(1/101)

    • B. 

      (1/100001)x(1/101)x(1/101)

    • C. 

      (1/10001)x(1/1001)x(1/1001)

    • D. 

      (1/1001)x(1/10001)x(1/10001)

    • E. 

      (1/101)x(1/100001)x(1/100001)

  • 20. 
    Which of the bases in Figure 5 is not found on DNA
    • A. 

      5a

    • B. 

      5b

    • C. 

      5c

    • D. 

      5d

    • E. 

      5e

  • 21. 
    Which of the molecules in Figure 6 is used in DNA sequencing reactions
    • A. 

      6a

    • B. 

      6b

    • C. 

      6c

    • D. 

      6d

    • E. 

      6e

  • 22. 
    In your laboratory, you plan to use CM (Figure 3) ion exchange chromatography to separate a peptide from a mixture of different peptides (shown below) at pH 7.0. Which of the following peptides would have the strongest binding affinity to the CM groups.
    • A. 

      GLEKSLVRLGDVQPSLGKESRAKKFQRQ

    • B. 

      GLEESLVDLGEVQPSLGAESRAKKFQDQ

    • C. 

      GLKESLVKLGDVEPSDGLESFARVFQDQ

    • D. 

      QDQFVRAFSELGDSPEVDGLKVLSEKLG

    • E. 

      QRQFDEAHSEQGLSPQVDGLYVLSTELG

  • 23. 
    Biochemists sometimes link a recombinant protein to a protein known as green fluorescent protein (GFP), which was first purified from bioluminescent jellyfish. The fluorophore in GFP (shown in Figure 2) is a derivative of three consecutive amino acids that undergo cyclization of the polypeptide chain and an oxidation. Identify the three residues that form the fluorophore.
    • A. 

      SYG

    • B. 

      TYG

    • C. 

      STG

    • D. 

      GTS

    • E. 

      GYS

  • 24. 
    According to Table 4, which of the following statements is incorrect.
    • A. 

      MspI and AsuI generate sticky ends

    • B. 

      EcoRI and PstI generate sticky ends

    • C. 

      SauI and NotI generate sticky ends

    • D. 

      AluI and EcoRV generate blunt ends

    • E. 

      AsuI and SauI cleave palindromic DNA sequences

  • 25. 
    The sequence of the template DNA for the sequencing gel shown in Figure 1 is
    • A. 

      3'AGTTFCTACC5'

    • B. 

      3'GGTAGCAACT5'

    • C. 

      3'CCATCGTTGA5'

    • D. 

      3'TCAACAGTTG5'

Back to Top Back to top