Ch4 Biochem Bashar Khatib

15 Questions | Total Attempts: 697

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Biochemistry Quizzes & Trivia

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Questions and Answers
  • 1. 
    The disulfide bonds -S-S can be formed in primary structure of proteins by :
    • A. 

      Isoleucine 

    • B. 

      Glutamic acid

    • C. 

      Valine

    • D. 

      Cysteins 

  • 2. 
    One of the following is incorrect about Collagen :
    • A. 

      Collagen is considered a fibrous protein 

    • B. 

      30% of the amino acids in the collagen are Pro and Hyp 

    • C. 

      Every second position in the sequence of amino acids in collagen fiber must be Gly

    • D. 

      Each polypeptide chain in collagen fiber is a helix 

  • 3. 
    Protein folding required that peptide backbone structures be able to change its direction and conformation :
    • A. 

      True

    • B. 

      False

  • 4. 
    A repetitive of super secondary structures and give information about folding :
    • A. 

      Domain

    • B. 

      Modules

    • C. 

      Reverse turn 

    • D. 

      Electrostatic interaction 

  • 5. 
    In disturbing of alpha-helix, the proximity of several side chains of like charge  lead to :
    • A. 

      Strong electrostatic repulsion 

    • B. 

      Crowding 

    • C. 

      Presence of proline amino acid 

    • D. 

      Steric repulsion 

  • 6. 
    Non-covalent bonds that occur between the non-polar side residues in the interior of proteins :
    • A. 

      Hydrophobic bonds

    • B. 

      Metal ion interactions 

    • C. 

      H-bonds

    • D. 

      Electrostatic bonds

  • 7. 
    The 4-pyrole rings of the Protoporphyrin in heme group  connected to each other by :
    • A. 

      Imidazole

    • B. 

      Methine bridges

    • C. 

      Ferrous iron

    • D. 

      His F8

  • 8. 
    Which way of proteins denaturing ways  mainly reduces electrostatic interactions :
    • A. 

      B-mercaptoethanol 

    • B. 

      Detergents by SDS

    • C. 

      High or low PH

    • D. 

      Urea or guanidine

  • 9. 
    When one oxygen molecule is binding of myoglobin, it becomes easier for next oxygen to bind , binding first oxygen facilities second and so on .. 
    • A. 

      True

    • B. 

      False

  • 10. 
    Which of the following is correct :
    • A. 

      Hb F has no affinity to O2

    • B. 

      There is a  His amino acid in position 143 in gamma chain in Hb F 

    • C. 

      BPG can bind to Hb F 

    • D. 

      There is a substitution between His and Ser amino acid in gamma chain in Hb F

    • E. 

      Option 5

  • 11. 
    The _______ is the single shape a protein adopts under physiological conditions.
    • A. 

       minimal configuration

    • B. 

      Native conformation

    • C. 

      Primary structure

    • D. 

      Most stable enantiomer

  • 12. 
    Which statement is false about a globular proteins that performs its biological function as a single independent polypeptide chain?
    • A. 

      Its tertiary structure is likely stabilized by the interactions of amino acid side chains in non-neighboring regions of the polypeptide chain

    • B. 

      It could contain α-helices that are stabilized my hydrogen bonding.

    • C. 

      It likely has extensive quaternary structure to maintain its globular shape.

    • D. 

       Non-covalent forces are the primary source of stability for the secondary and tertiary structure.

  • 13. 
    What does it mean to say a protein is oligomeric?
    • A. 

      In vivo it establishes an equilibrium between two or more active conformations

    • B. 

      It has more than fifty amino acids.

    • C. 

      The active protein involves the association of two or more polypeptide chains

    • D. 

      The proteins has multiple α-helices.

  • 14. 
    Conditions in the tissues which enhance the delivery of oxygen by hemoglobin are the presence of
    • A. 

      Carbon dioxide.

    • B. 

       2,3 BPG

    • C. 

      Protons.

    • D. 

      All of the above.

    • E. 

       A and B above

  • 15. 
    A hyperbolic binding curve differs from a sigmoidal binding curve in that the hyperbolic curve
    • A. 

      Has a single equilibrium constant for oxygen binding

    • B. 

       binds more oxygen after the initial proteins first bind oxygen

    • C. 

      Shows cooperativity.

    • D. 

      Binds up to four molecules of oxygen

    • E. 

      All of the above

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