BCH 3053 Exam 1-Questions With
100% Verified Answers.
_____ the number of water molecules that are ordered around hydrophobic groups ____ the
entropy of the bulk water - ✔✔Decreasing, increases
If a system has increasing OH- concentration, what is happening to the pH? - ✔✔pH is
increasing
Which of the following is the strongest interaction:
Hydrogen bond in a hydrophilic environment.
Hydrogen bond in an aqueous solution.
Hydrogen bond in a hydrophobic environment.
Ionic bond in water - ✔✔Hydrophobic environment (Hydrophobic groups are not
precisely bonded to each other, but rather are held together because of a repulsion from
water)
A technician is examining a chemical reaction. The technician notes that the reaction
requires 7.14 kcal/mol of energy per biomolecule synthesized. The reaction itself produces
21.42 kcal/mol of energy. The technician argues that this is enough energy to make 3 of the
biomolecules.
, What error has the student made in the analysis? - ✔✔The technician has not remembered
the 2nd Law of Thermodynamics (Out of 21.42kcal/mol some of the energy will be wasted and
it would not be sufficient and is not enough to synthesize 3 biomolecules)
What is the charge on the tetrapeptide Lys-Lys-His-Glu at pH 7? - ✔✔+1 (+1 +1 0 -1)
What is the predominant charge of the amino acid abbreviated E at pH 7? - ✔✔Negative
(Glu = -1)
Which group or groups on peptide contribute most to its overall acid base properties -
✔✔The R groups on the protein
Which of the following correctly describes peptide bonds? - ✔✔They are special type
of amide bond
They are formed through a dehydration reaction with an amino group and a carboxylic acid
They are a bond which displays resonance
They are a very stable bond
Which of the following amino acids can form crosslinks in proteins or cyclize peptides?
- ✔✔C (disulfide bonds)
Which of the following amino acids would be the easiest to distinguish from the other three in
a titration? - ✔✔K (G V and F are nonpolar)
The pKa values for the amino acid glycine are: pKa,1 = 2.3 and pKa,2 = 9.6. At what pH
value or pH values would glycine be most effective as a buffer? - ✔✔2.3 and 9.6 (An acid-
base buffer works best when the pH of the solution lies near pKa of the acid)
100% Verified Answers.
_____ the number of water molecules that are ordered around hydrophobic groups ____ the
entropy of the bulk water - ✔✔Decreasing, increases
If a system has increasing OH- concentration, what is happening to the pH? - ✔✔pH is
increasing
Which of the following is the strongest interaction:
Hydrogen bond in a hydrophilic environment.
Hydrogen bond in an aqueous solution.
Hydrogen bond in a hydrophobic environment.
Ionic bond in water - ✔✔Hydrophobic environment (Hydrophobic groups are not
precisely bonded to each other, but rather are held together because of a repulsion from
water)
A technician is examining a chemical reaction. The technician notes that the reaction
requires 7.14 kcal/mol of energy per biomolecule synthesized. The reaction itself produces
21.42 kcal/mol of energy. The technician argues that this is enough energy to make 3 of the
biomolecules.
, What error has the student made in the analysis? - ✔✔The technician has not remembered
the 2nd Law of Thermodynamics (Out of 21.42kcal/mol some of the energy will be wasted and
it would not be sufficient and is not enough to synthesize 3 biomolecules)
What is the charge on the tetrapeptide Lys-Lys-His-Glu at pH 7? - ✔✔+1 (+1 +1 0 -1)
What is the predominant charge of the amino acid abbreviated E at pH 7? - ✔✔Negative
(Glu = -1)
Which group or groups on peptide contribute most to its overall acid base properties -
✔✔The R groups on the protein
Which of the following correctly describes peptide bonds? - ✔✔They are special type
of amide bond
They are formed through a dehydration reaction with an amino group and a carboxylic acid
They are a bond which displays resonance
They are a very stable bond
Which of the following amino acids can form crosslinks in proteins or cyclize peptides?
- ✔✔C (disulfide bonds)
Which of the following amino acids would be the easiest to distinguish from the other three in
a titration? - ✔✔K (G V and F are nonpolar)
The pKa values for the amino acid glycine are: pKa,1 = 2.3 and pKa,2 = 9.6. At what pH
value or pH values would glycine be most effective as a buffer? - ✔✔2.3 and 9.6 (An acid-
base buffer works best when the pH of the solution lies near pKa of the acid)
