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Home Biochemistry Structure and Properties of Peptides Comments

  • Question
  • The heme is held in place by a bond between


  • Options
  • A. the Fe2+ and cysteine
  • B. the Fe3+ and histidine
  • C. the Fe3+ and cysteine
  • D. the Fe2+ and histidine

  • Correct Answer
  • the Fe2+ and histidine 


  • Structure and Properties of Peptides problems


    Search Results


    • 1. The major element of secondary structure in myoglobin and hemoglobin is

    • Options
    • A. the P-strand
    • B. the a-helix
    • C. the reverse turn
    • D. All of these
    • Discuss
    • 2. Which hemoglobin chain replaces the beta chain in embryonic hemoglobulin?

    • Options
    • A. Delta
    • B. Epsilon
    • C. Gamma
    • D. Alfa
    • Discuss
    • 3. In deoxy hemoglobin (Hb), the Fe (II) is coordinated to

    • Options
    • A. four nitrogens of heme, the proximal His, and a water molecule
    • B. four nitrogens of heme and to a water molecule
    • C. two nitrogens of heme and to three His residues in Hb
    • D. two nitrogens of heme and to three water molecules
    • Discuss
    • 4. If the F and Y angles of each peptide unit in a protein are known, which of the following may also be determined?

    • Options
    • A. Complete secondary structure
    • B. Complete tertiary structure
    • C. Complete quaternary structure
    • D. Thermodynamic stability
    • Discuss
    • 5. The peptide, Val-Lys-Glu-Met-Ser-Trp-Arg-Ala, was digested with cyanogen bromide (CNBr) to produce:

    • Options
    • A. Val-Lys + Glu-Met-Ser + Trp-Arg-Ala
    • B. Val-Lys-Glu-Met-Ser-Trp + Arg-Ala
    • C. Val-Lys-Glu-Met + Ser-Trp-Arg-Ala
    • D. Val-Lys-Glu + Met-Ser-Trp-Arg-Ala
    • Discuss
    • 6. Which of the three subunits of the G proteins binds GDP and GTP?

    • Options
    • A. Alpha
    • B. Beta
    • C. Gamma
    • D. Delta
    • Discuss
    • 7. For the unfolding reaction of Protein G, ∆H° =210.6 kJ/mol, this means that

    • Options
    • A. unfolding is favored enthalpically
    • B. folding is favored enthalpically
    • C. the entropy is positive at all temperatures
    • D. the entropy is negative at all temperatures
    • Discuss
    • 8. The correlation between free energy ?G transfer between the aqueous/organic phases and the surface area of amino acid residues

    • Options
    • A. reflects the reduction in solvent-accessible area during protein folding
    • B. is only meaningful for the polar amino acids
    • C. ignores the important contribution of the peptide bond
    • D. is similar to effects seen with SDS denaturation
    • Discuss
    • 9. Buried hydrophobic side chains in a globular protein fit into a hole formed by the side chains of

    • Options
    • A. 1-3 other amino acids
    • B. 5-7 other amino acids
    • C. 9-12 other amino acids
    • D. 13-15 other amino acids
    • Discuss
    • 10. Unpaired H-bond donors and acceptors are found in the hydrophobic core of a protein

    • Options
    • A. only at the ends of a-helices
    • B. only at the turns connecting p-strands
    • C. only on Pro residues
    • D. rarely
    • Discuss


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