BIOCHEM 210 COMPREHENSIVE EXAM
(MODULES 1-8) QUESTIONS AND
ANSWERS 100% VERIFIED
1. Which of the following properties of water is primarily responsible for its high boiling
point?
A. Hydrogen bonding between molecules
B. Covalent bonding within the molecule
C. Ionic interactions with solutes
D. Van der Waals forces
Answer: A
Conceptual Explanation: Hydrogen bonding between water molecules requires
significant energy to break, leading to a high boiling point compared to similar molecules.
2. If the pH of a solution is 5.0, what is the concentration of hydroxide ions [OH-]?
A. 10^-9 M
B. 10^-7 M
C. 10^-5 M
D. 10^-14 M
,Answer: A
Conceptual Explanation: Since pH + pOH = 14, a pH of 5 means pOH is 9. Therefore, [OH-]
= 10^-9 M.
3. A reaction is spontaneous at all temperatures if:
A. Delta H is positive and Delta S is negative
B. Delta H is positive and Delta S is positive
C. Delta H is negative and Delta S is positive
D. Delta H is negative and Delta S is negative
Answer: C
Conceptual Explanation: According to Gibbs Free Energy (Delta G = Delta H - T*Delta S), a
negative enthalpy and positive entropy result in a negative Delta G at any temperature.
4. Which amino acid contains a thiol group in its side chain?
A. Methionine
B. Cysteine
C. Serine
D. Threonine
Answer: B
, Conceptual Explanation: Cysteine has a reactive sulfhydryl (-SH) or thiol group, which
can form disulfide bonds.
5. Which level of protein structure is defined by the local spatial arrangement of the
polypeptide backbone?
A. Primary
B. Quaternary
C. Tertiary
D. Secondary
Answer: D
Conceptual Explanation: Secondary structure refers to local folded structures like alpha
helices and beta sheets formed by hydrogen bonds in the backbone.
6. The peptide bond is characterized by:
A. A partial double-bond character due to resonance
B. Full rotation around the C-N bond
C. Being longer than a typical single bond
D. Non-polar covalent nature
Answer: A
Conceptual Explanation: Resonance gives the peptide bond a partial double-bond
character, making it planar and rigid with restricted rotation.
(MODULES 1-8) QUESTIONS AND
ANSWERS 100% VERIFIED
1. Which of the following properties of water is primarily responsible for its high boiling
point?
A. Hydrogen bonding between molecules
B. Covalent bonding within the molecule
C. Ionic interactions with solutes
D. Van der Waals forces
Answer: A
Conceptual Explanation: Hydrogen bonding between water molecules requires
significant energy to break, leading to a high boiling point compared to similar molecules.
2. If the pH of a solution is 5.0, what is the concentration of hydroxide ions [OH-]?
A. 10^-9 M
B. 10^-7 M
C. 10^-5 M
D. 10^-14 M
,Answer: A
Conceptual Explanation: Since pH + pOH = 14, a pH of 5 means pOH is 9. Therefore, [OH-]
= 10^-9 M.
3. A reaction is spontaneous at all temperatures if:
A. Delta H is positive and Delta S is negative
B. Delta H is positive and Delta S is positive
C. Delta H is negative and Delta S is positive
D. Delta H is negative and Delta S is negative
Answer: C
Conceptual Explanation: According to Gibbs Free Energy (Delta G = Delta H - T*Delta S), a
negative enthalpy and positive entropy result in a negative Delta G at any temperature.
4. Which amino acid contains a thiol group in its side chain?
A. Methionine
B. Cysteine
C. Serine
D. Threonine
Answer: B
, Conceptual Explanation: Cysteine has a reactive sulfhydryl (-SH) or thiol group, which
can form disulfide bonds.
5. Which level of protein structure is defined by the local spatial arrangement of the
polypeptide backbone?
A. Primary
B. Quaternary
C. Tertiary
D. Secondary
Answer: D
Conceptual Explanation: Secondary structure refers to local folded structures like alpha
helices and beta sheets formed by hydrogen bonds in the backbone.
6. The peptide bond is characterized by:
A. A partial double-bond character due to resonance
B. Full rotation around the C-N bond
C. Being longer than a typical single bond
D. Non-polar covalent nature
Answer: A
Conceptual Explanation: Resonance gives the peptide bond a partial double-bond
character, making it planar and rigid with restricted rotation.
