BIOMG 3300 - Unit 2 Questions with Correct Answers
what does the biological activity of a protein depend on? Correct
Answer-it's 3D structure and its interaction with other molecules
prosthetic group Correct Answer-a metal ion or organic compound
(other than an amino acid) covalently bound to a protein and essential to
its activity
modification types of amino acids Correct Answer-
primary structure Correct Answer-a description of the covalent
backbone of a polymer, including the sequence of monomeric subunits
and any interchain and intrachain covalent bonds
secondary structure Correct Answer-the regularly repeating
conformations of the polypeptide backbone such as α helices and β
pleated sheets
(always involve H-bonds in a regular pattern that stabilize the peptide
bonds that are drawn into the core)
tertiary structure Correct Answer-the completely folded, 3D,
biologically active (or native) conformation of a single polypeptide
protein
(nature of the amino acid side chains an important factor)
,quaternary structure Correct Answer-the 3D structure of a multisubunit
protein, particularly the manner in which the subunits fit together
what holds together proteins and causes all interactions between
molecules? Correct Answer-hydrogen bonds, ionic bonds/interactions,
hydrophobic interactions, and van der Waals interactions (and disulfide
bonds in oxidizing environments)
what strengthens van der Waals forces? Correct Answer-- more
electrons
- closer proximity
what are the two rules of protein folding? Correct Answer-1)
hydrophobic residues tend to be in interior of protein.
2) maximize hydrogen bonds and ionic interactions within the protein,
minimize number of unpair residues that can hydrogen bond or form
ionic interactions
hydrophobic interactions contribute to what in a protein? Correct
Answer-protein folding (hydrophobic groups fold into the protein)
ionic bonds limit what? Correct Answer-protein flexibility
van der Waals interactions have what contribution to proteins? Correct
Answer-have a substantial contribution to the structures of well-packed
proteins and between 2 proteins
, polypeptide chains are ________, but the peptide bond ___________.
Correct Answer-flexible; doesn't rotate
discuss the planar nature of the peptide bond. Correct Answer-the six
atoms of the peptide group lie in a single plane
can the peptide bond rotate? why or why not? Correct Answer-the
peptide C-N bonds cannot rotate freely because of their partial double-
bond character
within a peptide bond, is the hydrogen of the amino group usually trans
(opposite side) or cis (same side) relative to the oxygen of the carbonyl?
Correct Answer-the H of the amino group is usually trans (opposite side)
relative to the O of the carbonyl within a peptide bond
discuss rotation of the φ and ψ bonds in terms of the Ramachandran plot.
What is the basis of this restriction? Correct Answer-the rotation of the φ
and ψ bonds is restricted to -180 and +180 degrees because of steric
interference caused by van der Waals radii (areas of darker color have
less interference)
the α helix found in proteins is _______-handed. Correct Answer-right
is there a hole in the middle of the a helix? Correct Answer-there
appears to be a hole, but the figure does not take into account van der
Waals radii, and the atoms in the middle are very close together
what does the biological activity of a protein depend on? Correct
Answer-it's 3D structure and its interaction with other molecules
prosthetic group Correct Answer-a metal ion or organic compound
(other than an amino acid) covalently bound to a protein and essential to
its activity
modification types of amino acids Correct Answer-
primary structure Correct Answer-a description of the covalent
backbone of a polymer, including the sequence of monomeric subunits
and any interchain and intrachain covalent bonds
secondary structure Correct Answer-the regularly repeating
conformations of the polypeptide backbone such as α helices and β
pleated sheets
(always involve H-bonds in a regular pattern that stabilize the peptide
bonds that are drawn into the core)
tertiary structure Correct Answer-the completely folded, 3D,
biologically active (or native) conformation of a single polypeptide
protein
(nature of the amino acid side chains an important factor)
,quaternary structure Correct Answer-the 3D structure of a multisubunit
protein, particularly the manner in which the subunits fit together
what holds together proteins and causes all interactions between
molecules? Correct Answer-hydrogen bonds, ionic bonds/interactions,
hydrophobic interactions, and van der Waals interactions (and disulfide
bonds in oxidizing environments)
what strengthens van der Waals forces? Correct Answer-- more
electrons
- closer proximity
what are the two rules of protein folding? Correct Answer-1)
hydrophobic residues tend to be in interior of protein.
2) maximize hydrogen bonds and ionic interactions within the protein,
minimize number of unpair residues that can hydrogen bond or form
ionic interactions
hydrophobic interactions contribute to what in a protein? Correct
Answer-protein folding (hydrophobic groups fold into the protein)
ionic bonds limit what? Correct Answer-protein flexibility
van der Waals interactions have what contribution to proteins? Correct
Answer-have a substantial contribution to the structures of well-packed
proteins and between 2 proteins
, polypeptide chains are ________, but the peptide bond ___________.
Correct Answer-flexible; doesn't rotate
discuss the planar nature of the peptide bond. Correct Answer-the six
atoms of the peptide group lie in a single plane
can the peptide bond rotate? why or why not? Correct Answer-the
peptide C-N bonds cannot rotate freely because of their partial double-
bond character
within a peptide bond, is the hydrogen of the amino group usually trans
(opposite side) or cis (same side) relative to the oxygen of the carbonyl?
Correct Answer-the H of the amino group is usually trans (opposite side)
relative to the O of the carbonyl within a peptide bond
discuss rotation of the φ and ψ bonds in terms of the Ramachandran plot.
What is the basis of this restriction? Correct Answer-the rotation of the φ
and ψ bonds is restricted to -180 and +180 degrees because of steric
interference caused by van der Waals radii (areas of darker color have
less interference)
the α helix found in proteins is _______-handed. Correct Answer-right
is there a hole in the middle of the a helix? Correct Answer-there
appears to be a hole, but the figure does not take into account van der
Waals radii, and the atoms in the middle are very close together
