Ch4 Biochem Bashar Khatib

15 Questions | By Pharmacgy | Last updated: Mar 21, 2022 | Total Attempts: 697

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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