BIOC192 MCQ POOL UPDATED Exam
Questions and CORRECT Answers
C) amino acids linked together by amide covalent bonds - Correct Answer- Proteins are
polymers of:
A) nucleoside monophosphates linked together by covalent bonds.
B) amino acids linked together by ester covalent bonds.
C) amino acids linked together by amide covalent bonds.
D) amino acids linked together by non-covalent peptide bonds.
D) Hydrophobic interactions
Because it is nonpolar.
(Phenylalanine) - Correct Answer- The side-chain of the amino acid above:
A) can be ionised to COO- and NH3
+ at pH 7.
B) is most often found on the surface of a protein exposed to aqueous solvent.
C) is likely to participate in hydrogen bonding that stabilises the tertiary structure of a
protein.
D) can participate in hydrophobic interactions in the core of a globular protein.
B) This amino acid is likely to be found in the core (middle) of a protein associated with
other non-polar amino acids.
INCORRECT because this is Glutamic Acid, which is POLAR - Correct Answer- Above is a
picture of an amino acid. Which one of the following statements about this amino acid is
INCORRECT?
A) This amino acid has a polar side-chain.
B) This amino acid is likely to be found in the core (middle) of a protein associated with
other non-polar amino acids.
C) This amino acid is able to form ionic bonds at pH 7.
D) The side-chain of this amino acid could be classified as acidic.
,A) the side chains of lysine and arginine are unable to participate in ionic bonds that stabilise
the tertiary structure of a protein. - Correct Answer- Which ONE of the following statements
about amino acids is INCORRECT?
A) the side chains of lysine and arginine are unable to participate in ionic bonds that stabilise
the tertiary structure of a protein.
B) the side-chain carboxyl groups of glutamate and aspartate are deprotonated at neutral pH.
C) the side-chains of valine, leucine and isoleucine are likely to be located away from the
surface of a protein.
D) two cysteine side-chains can form a covalent bond.
B) in the middle of a polypeptide chain is plus (+)1 - Correct Answer- The amino acid lysine
contains an alpha amino group, an alpha carbon atom, an alpha carboxyl group and a side
chain structure which includes an amino group (the pKa of an amino groups is basic and the
pKa of a carboxyl group is acidic).
The net charge on a lysine amino acid at pH 7.0:
A) as a free amino acid is minus (-)1.
B) in the middle of a polypeptide chain is plus (+)1.
C) at the N-terminus of a protein is plus (+)1.
D) at the C-terminus of a protein is minus (-)1.
B) The peptide bond is never in the cis conformation
Usually trans, but can be cis - Correct Answer- Which one of the following statements about
the peptide bond in proteins is INCORRECT?
A) The peptide bond is planar.
B) The peptide bond is never in the cis conformation.
C) The peptide bond is rigid.
D) The peptide bond is an example of an amide bond.
B) always trans
Usually trans, but can be cis - Correct Answer- Which one of the following is NOT a property
of a peptide bond?
A) planar
B) always trans
C) has a dipole moment
,D) partial double bond character
C) 3.6 - Correct Answer- The number of amino acids in each turn of a protein alpha-helix is
closest to which one
of the following values?
A) 1.5
B) 3.1
C) 3.6
D) 5.0
C) contains 3.6 amino acids per turn, does not normally contain proline and is often polar on
one side and non-polar on the other side. - Correct Answer- An alpha helix in a protein:
A) contains 3.6 amino acids per turn and is stabilised by covalent crosslinks.
B) contains four amino acids per turn and is stabilised by hydrogen bonds between every
fourth amino acid.
C) contains 3.6 amino acids per turn, does not normally contain proline and is often polar on
one side and non-polar on the other side.
D) contains 3.6 amino acids per turn, has the amino acid side chains facing the inside of the
helix and can vary in length.
D) all the hydrophobic residues are buried inside the helix - Correct Answer- Which one of
the following is NOT a property of an alpha-helix?
A) stabilized by hydrogen bonds
B) 3.6 residues per turn
C) has a dipole
D) all the hydrophobic residues are buried inside the helix
C) Beta-sheets are stabilised by hydrogen bonds between carbonyl oxygens and amino
hydrogens from amino acids that are next to each other in a beta-strand. - Correct Answer-
Which ONE of the following statements about protein structure is INCORRECT?
A) Alpha-helices are stabilised by hydrogen bonds between carbonyl oxygens and amino
hydrogens along the backbone of a polypeptide chain.
B) Non-polar amino acids moving away from water provide some of the folding energy for
the three-dimensional folding of a protein.
, C) Beta-sheets are stabilised by hydrogen bonds between carbonyl oxygens and amino
hydrogens from amino acids that are next to each other in a beta-strand.
D) The information for determining the final tertiary structure of a protein is in the linear
sequence of amino acids for any given polypeptide chain
B) structural features that have more than one secondary structure (alpha-helix, beta-sheet)
element. - Correct Answer- In proteins, supersecondary structures are:
A) extra-large alpha-helices and beta-sheets.
B) structural features that have more than one secondary structure (alpha-helix, beta-sheet)
element.
C) β-turns between alpha-helices.
D) always joined together by disulphide bonds between cysteine residues from different
secondary structure elements.
C) the folding of the primary amino acid sequence into various secondary structure elements
that are stabilised mainly by non-covalent bonds. - Correct Answer- The tertiary structure of a
protein results from:
A) the folding of the primary amino acid sequence into various super-secondary structure
elements that are stabilised mainly by covalent bonds.
B) the arrangement of quaternary structure in 3-dimensional space.
C) the folding of the primary amino acid sequence into various secondary structure elements
that are stabilised mainly by non-covalent bonds.
D) the folding of the amino acid sequence in a totally random manner.
D) Hydrogen bonds between non-polar amino acid side chains stabilise the hydrophobic
interactions at the core of a globular protein. - Correct Answer- Which one of the following
statements is INCORRECT?
A) Hydrogen bonding is important for stabilising secondary structure in proteins.
B) Hydrogen bonds in alpha helices form between the carbonyl oxygen from a peptide bond
and the amino hydrogen from a different peptide bond further along the
polypeptide chain.
C) Hydrogen bonds between amino acid side-chains can stabilise the tertiary structure of
proteins.
D) Hydrogen bonds between non-polar amino acid side chains stabilise the hydrophobic
interactions at the core of a globular protein.
Questions and CORRECT Answers
C) amino acids linked together by amide covalent bonds - Correct Answer- Proteins are
polymers of:
A) nucleoside monophosphates linked together by covalent bonds.
B) amino acids linked together by ester covalent bonds.
C) amino acids linked together by amide covalent bonds.
D) amino acids linked together by non-covalent peptide bonds.
D) Hydrophobic interactions
Because it is nonpolar.
(Phenylalanine) - Correct Answer- The side-chain of the amino acid above:
A) can be ionised to COO- and NH3
+ at pH 7.
B) is most often found on the surface of a protein exposed to aqueous solvent.
C) is likely to participate in hydrogen bonding that stabilises the tertiary structure of a
protein.
D) can participate in hydrophobic interactions in the core of a globular protein.
B) This amino acid is likely to be found in the core (middle) of a protein associated with
other non-polar amino acids.
INCORRECT because this is Glutamic Acid, which is POLAR - Correct Answer- Above is a
picture of an amino acid. Which one of the following statements about this amino acid is
INCORRECT?
A) This amino acid has a polar side-chain.
B) This amino acid is likely to be found in the core (middle) of a protein associated with
other non-polar amino acids.
C) This amino acid is able to form ionic bonds at pH 7.
D) The side-chain of this amino acid could be classified as acidic.
,A) the side chains of lysine and arginine are unable to participate in ionic bonds that stabilise
the tertiary structure of a protein. - Correct Answer- Which ONE of the following statements
about amino acids is INCORRECT?
A) the side chains of lysine and arginine are unable to participate in ionic bonds that stabilise
the tertiary structure of a protein.
B) the side-chain carboxyl groups of glutamate and aspartate are deprotonated at neutral pH.
C) the side-chains of valine, leucine and isoleucine are likely to be located away from the
surface of a protein.
D) two cysteine side-chains can form a covalent bond.
B) in the middle of a polypeptide chain is plus (+)1 - Correct Answer- The amino acid lysine
contains an alpha amino group, an alpha carbon atom, an alpha carboxyl group and a side
chain structure which includes an amino group (the pKa of an amino groups is basic and the
pKa of a carboxyl group is acidic).
The net charge on a lysine amino acid at pH 7.0:
A) as a free amino acid is minus (-)1.
B) in the middle of a polypeptide chain is plus (+)1.
C) at the N-terminus of a protein is plus (+)1.
D) at the C-terminus of a protein is minus (-)1.
B) The peptide bond is never in the cis conformation
Usually trans, but can be cis - Correct Answer- Which one of the following statements about
the peptide bond in proteins is INCORRECT?
A) The peptide bond is planar.
B) The peptide bond is never in the cis conformation.
C) The peptide bond is rigid.
D) The peptide bond is an example of an amide bond.
B) always trans
Usually trans, but can be cis - Correct Answer- Which one of the following is NOT a property
of a peptide bond?
A) planar
B) always trans
C) has a dipole moment
,D) partial double bond character
C) 3.6 - Correct Answer- The number of amino acids in each turn of a protein alpha-helix is
closest to which one
of the following values?
A) 1.5
B) 3.1
C) 3.6
D) 5.0
C) contains 3.6 amino acids per turn, does not normally contain proline and is often polar on
one side and non-polar on the other side. - Correct Answer- An alpha helix in a protein:
A) contains 3.6 amino acids per turn and is stabilised by covalent crosslinks.
B) contains four amino acids per turn and is stabilised by hydrogen bonds between every
fourth amino acid.
C) contains 3.6 amino acids per turn, does not normally contain proline and is often polar on
one side and non-polar on the other side.
D) contains 3.6 amino acids per turn, has the amino acid side chains facing the inside of the
helix and can vary in length.
D) all the hydrophobic residues are buried inside the helix - Correct Answer- Which one of
the following is NOT a property of an alpha-helix?
A) stabilized by hydrogen bonds
B) 3.6 residues per turn
C) has a dipole
D) all the hydrophobic residues are buried inside the helix
C) Beta-sheets are stabilised by hydrogen bonds between carbonyl oxygens and amino
hydrogens from amino acids that are next to each other in a beta-strand. - Correct Answer-
Which ONE of the following statements about protein structure is INCORRECT?
A) Alpha-helices are stabilised by hydrogen bonds between carbonyl oxygens and amino
hydrogens along the backbone of a polypeptide chain.
B) Non-polar amino acids moving away from water provide some of the folding energy for
the three-dimensional folding of a protein.
, C) Beta-sheets are stabilised by hydrogen bonds between carbonyl oxygens and amino
hydrogens from amino acids that are next to each other in a beta-strand.
D) The information for determining the final tertiary structure of a protein is in the linear
sequence of amino acids for any given polypeptide chain
B) structural features that have more than one secondary structure (alpha-helix, beta-sheet)
element. - Correct Answer- In proteins, supersecondary structures are:
A) extra-large alpha-helices and beta-sheets.
B) structural features that have more than one secondary structure (alpha-helix, beta-sheet)
element.
C) β-turns between alpha-helices.
D) always joined together by disulphide bonds between cysteine residues from different
secondary structure elements.
C) the folding of the primary amino acid sequence into various secondary structure elements
that are stabilised mainly by non-covalent bonds. - Correct Answer- The tertiary structure of a
protein results from:
A) the folding of the primary amino acid sequence into various super-secondary structure
elements that are stabilised mainly by covalent bonds.
B) the arrangement of quaternary structure in 3-dimensional space.
C) the folding of the primary amino acid sequence into various secondary structure elements
that are stabilised mainly by non-covalent bonds.
D) the folding of the amino acid sequence in a totally random manner.
D) Hydrogen bonds between non-polar amino acid side chains stabilise the hydrophobic
interactions at the core of a globular protein. - Correct Answer- Which one of the following
statements is INCORRECT?
A) Hydrogen bonding is important for stabilising secondary structure in proteins.
B) Hydrogen bonds in alpha helices form between the carbonyl oxygen from a peptide bond
and the amino hydrogen from a different peptide bond further along the
polypeptide chain.
C) Hydrogen bonds between amino acid side-chains can stabilise the tertiary structure of
proteins.
D) Hydrogen bonds between non-polar amino acid side chains stabilise the hydrophobic
interactions at the core of a globular protein.
