BCH Final Exam Set
After the following features are common to all living organisms, except: - correct answer ✔✔cellular
structures
identify the functional group(s) in the molecule - correct answer ✔✔amide
Phosphoenolpyruvate donates a phosphate group to ADP to produce pyruvate and ATP. The ΔG value for
this reaction at 25°C is -63 kJ/mol and the value of ΔS is +190 J/K-mol. What is the value of ΔH? Is the
reaction exothermic or endothermic? - correct answer ✔✔-6.4 kj/mol, exothermic
A given reaction occurs spontaneously, with an exothermic change in enthalpy and an increase in
disorder. Which answer choice below correctly assigns the relative changes to ΔS, ΔH, and ΔG? - correct
answer ✔✔+)ΔS; (-)ΔH; and (-)ΔG
identify the class of basic biomolecules represented by the following structure. - correct answer
✔✔Amino acids
Which organelle does not contain DNA? - correct answer ✔✔Rough Endoplasmic Reticulum
A reaction will be spontaneous at all temperatures if what two conditions are met? - correct answer
✔✔a decrease in enthalpy and increase in entropy
If atoms with greatly differing electronegativities form a bond, that bond will be - correct answer
✔✔polar
The hydrophobic effect, resulting in the exclusion of nonpolar substances from an aqueous solution is
the result of the strong attractive force between the nonpolar molecules. - correct answer ✔✔false
In a typical hydrogen bond - correct answer ✔✔three atoms lie in a straight line
,Which of the following statements about hydrogen bonds is false? - correct answer ✔✔The donor is a
hydrogen atom bonded to a less electronegative atom then hydrogen.
What is the concentration of a lactic acid buffer (pKa 3.9) that contains 0.25 M CH3CH(OH)COOH and
0.15 M CH3CH(OH)COO-? What is the pH of the buffer? - correct answer ✔✔0.40 M; pH 3.68
Which would be a more effective buffer at pH 8.0? - correct answer ✔✔0 mM glycinamide (pKa 8.20)
Ionic compounds and polar covalent compounds tend to dissolve in water because of - correct answer
✔✔ion-dipole and dipole-dipole interactions.
Which of the following would be the strongest acid? - correct answer ✔✔Formic acid, pK 3.13
Formation of hydrogen bonds is fundamental to the assembly of the DNA double helix. How many
potential H-bond donor atoms are present in the nitrogenous base of GTP below (boxed area only)? -
correct answer ✔✔2
What is the pH of an acetic acid solution where the concentration of acetic acid is 2 mM and the
concentration of sodium acetate is 20 mM? The pKa of acetic acid is 4.76. - correct answer ✔✔5.76
Which groups of a pair of amino acids must react to form a peptide bond? - correct answer ✔✔the
carboxyl of one and the amino of the other
Which of the following types of amino acids has uncharged side chains at neutral pH? - correct answer
✔✔Polar-neutral amino acids
Which of the following is NOT a class of amino acid? - correct answer ✔✔asymmetric
Consider the titration curve below:
Which point would most likely represent the pKa value of the carboxyl group? - correct answer ✔✔2
, Consider the titration curve below:
Which point(s) would correspond to pK values? - correct answer ✔✔2 and 4
Which of the following is true about uncommon amino acids? - correct answer ✔✔They are formed in
the protein by post-translational modification of the parent amino acid.
Which of the following statements is true of resonance structures? - correct answer ✔✔Resonance
structures differ from one another only in the positioning of electrons.
Identify the amino acid below and classify it by polarity. - correct answer ✔✔R, polar
Identify the charged groups in the peptide below at pH 1.
Val-Met-Ser-Ile-Phe-Arg-Cys-Tyr-Leu - correct answer ✔✔Val, Arg, Leu
Which amino acid has a pI of 5.0? - correct answer ✔✔C
The sequence of monomers in any polymer is this type of structure: - correct answer ✔✔primary
structure
Hemoglobin is a heterotetramer that has 4 identical subunits. - correct answer ✔✔False
Which one is not an example of supersecondary structure? - correct answer ✔✔the pyrrole ring
Which of the following amino acid substitutions would be least likely to have a deleterious effect on
protein function? - correct answer ✔✔Leu changes to Ile
In the α helix the hydrogen bonds: - correct answer ✔✔occur mainly between electronegative atoms of
the backbone.
After the following features are common to all living organisms, except: - correct answer ✔✔cellular
structures
identify the functional group(s) in the molecule - correct answer ✔✔amide
Phosphoenolpyruvate donates a phosphate group to ADP to produce pyruvate and ATP. The ΔG value for
this reaction at 25°C is -63 kJ/mol and the value of ΔS is +190 J/K-mol. What is the value of ΔH? Is the
reaction exothermic or endothermic? - correct answer ✔✔-6.4 kj/mol, exothermic
A given reaction occurs spontaneously, with an exothermic change in enthalpy and an increase in
disorder. Which answer choice below correctly assigns the relative changes to ΔS, ΔH, and ΔG? - correct
answer ✔✔+)ΔS; (-)ΔH; and (-)ΔG
identify the class of basic biomolecules represented by the following structure. - correct answer
✔✔Amino acids
Which organelle does not contain DNA? - correct answer ✔✔Rough Endoplasmic Reticulum
A reaction will be spontaneous at all temperatures if what two conditions are met? - correct answer
✔✔a decrease in enthalpy and increase in entropy
If atoms with greatly differing electronegativities form a bond, that bond will be - correct answer
✔✔polar
The hydrophobic effect, resulting in the exclusion of nonpolar substances from an aqueous solution is
the result of the strong attractive force between the nonpolar molecules. - correct answer ✔✔false
In a typical hydrogen bond - correct answer ✔✔three atoms lie in a straight line
,Which of the following statements about hydrogen bonds is false? - correct answer ✔✔The donor is a
hydrogen atom bonded to a less electronegative atom then hydrogen.
What is the concentration of a lactic acid buffer (pKa 3.9) that contains 0.25 M CH3CH(OH)COOH and
0.15 M CH3CH(OH)COO-? What is the pH of the buffer? - correct answer ✔✔0.40 M; pH 3.68
Which would be a more effective buffer at pH 8.0? - correct answer ✔✔0 mM glycinamide (pKa 8.20)
Ionic compounds and polar covalent compounds tend to dissolve in water because of - correct answer
✔✔ion-dipole and dipole-dipole interactions.
Which of the following would be the strongest acid? - correct answer ✔✔Formic acid, pK 3.13
Formation of hydrogen bonds is fundamental to the assembly of the DNA double helix. How many
potential H-bond donor atoms are present in the nitrogenous base of GTP below (boxed area only)? -
correct answer ✔✔2
What is the pH of an acetic acid solution where the concentration of acetic acid is 2 mM and the
concentration of sodium acetate is 20 mM? The pKa of acetic acid is 4.76. - correct answer ✔✔5.76
Which groups of a pair of amino acids must react to form a peptide bond? - correct answer ✔✔the
carboxyl of one and the amino of the other
Which of the following types of amino acids has uncharged side chains at neutral pH? - correct answer
✔✔Polar-neutral amino acids
Which of the following is NOT a class of amino acid? - correct answer ✔✔asymmetric
Consider the titration curve below:
Which point would most likely represent the pKa value of the carboxyl group? - correct answer ✔✔2
, Consider the titration curve below:
Which point(s) would correspond to pK values? - correct answer ✔✔2 and 4
Which of the following is true about uncommon amino acids? - correct answer ✔✔They are formed in
the protein by post-translational modification of the parent amino acid.
Which of the following statements is true of resonance structures? - correct answer ✔✔Resonance
structures differ from one another only in the positioning of electrons.
Identify the amino acid below and classify it by polarity. - correct answer ✔✔R, polar
Identify the charged groups in the peptide below at pH 1.
Val-Met-Ser-Ile-Phe-Arg-Cys-Tyr-Leu - correct answer ✔✔Val, Arg, Leu
Which amino acid has a pI of 5.0? - correct answer ✔✔C
The sequence of monomers in any polymer is this type of structure: - correct answer ✔✔primary
structure
Hemoglobin is a heterotetramer that has 4 identical subunits. - correct answer ✔✔False
Which one is not an example of supersecondary structure? - correct answer ✔✔the pyrrole ring
Which of the following amino acid substitutions would be least likely to have a deleterious effect on
protein function? - correct answer ✔✔Leu changes to Ile
In the α helix the hydrogen bonds: - correct answer ✔✔occur mainly between electronegative atoms of
the backbone.
