, CHEM 210 | Module 3 | Original Biochemistry Practice
CHEM 210 Module 3 Exam | Biochemistry | Portage
| Q & A | 26/27 Actual (PDF)
1. An amino-acid chemistry problem requires the concept of amino acid side chain. Which
interpretation ismost accurate?
A) Amino Acid Side Chain has the opposite biochemical role from the definition given.
B) Amino Acid Side Chain is unrelated to amino acids, peptides, or proteins.
C) The side chain, or R group, determines many chemical properties of an amino acid such as polarity,
charge, andhydrophobicity.
D) Amino Acid Side Chain is determined only by molecular size and not by chemical structure.
Correct Answer: The side chain, or R group, determines many chemical properties of an amino acid such as
polarity, charge, and hydrophobicity.
Rationale: The side chain, or R group, determines many chemical properties of an amino acid such as polarity,
charge, and hydrophobicity. Amino-acid behavior depends on side-chain chemistry, protonation state, pH, and the
structure of the alpha-amino-acid backbone.
2. Which statement best describes cooperative binding in CHEM 210 Module 3?
A) Cooperative binding means ligand binding at one subunit affects ligand affinity at other subunits.
B) Cooperativity occurs only in monomeric proteins
C) Cooperative binding eliminates affinity changes
D) Cooperative binding means each subunit behaves independently
Correct Answer: Cooperative binding means ligand binding at one subunit affects ligand affinity at other
subunits.
Rationale: Cooperative binding means ligand binding at one subunit affects ligand affinity at other subunits. This
aligns with Portage Module 3's official focus on the 20 amino acids, peptide bonds, and protein structure-function
relationships.
3. Which statement best describes amino acid general structure in CHEM 210 Module 3?
A) A standard amino acid contains only an amino group
B) A standard alpha-amino acid contains an amino group, a carboxyl group, a hydrogen, and a variable side
chainattached to the alpha carbon.
C) The side chain is attached to the carboxyl carbon
D) All amino acids lack a carboxyl group
Correct Answer: A standard alpha-amino acid contains an amino group, a carboxyl group, a hydrogen, and a
variable side chain attached to the alpha carbon.
Rationale: A standard alpha-amino acid contains an amino group, a carboxyl group, a hydrogen, and a variable side
chain attached to the alpha carbon. This aligns with Portage Module 3's official focus on the 20 amino acids, peptide
bonds, and protein structure-function relationships.
4. A peptide or secondary-structure question involves peptide N-terminus. Which statement is correct?
A) The N-terminus is always written on the right
B) The N-terminus of a peptide contains the free amino group and is conventionally written on the left.
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, CHEM 210 | Module 3 | Original Biochemistry Practice
C) The N-terminus is the free carboxyl end
D) The N-terminus contains no nitrogen
Correct Answer: The N-terminus of a peptide contains the free amino group and is conventionally written on
the left.
Rationale: The N-terminus of a peptide contains the free amino group and is conventionally written on the left.
Peptide geometry and backbone hydrogen bonding are central to understanding primary and secondary protein
structure.
5. An amino-acid chemistry problem requires the concept of amino acid pKa. Which interpretation is
mostaccurate?
A) Amino Acid Pka is unrelated to amino acids, peptides, or proteins.
B) Amino Acid Pka has the opposite biochemical role from the definition given.
C) The pKa values of ionizable amino-acid groups determine their protonation state at a given pH.
D) Amino Acid Pka is determined only by molecular size and not by chemical structure.
Correct Answer: The pKa values of ionizable amino-acid groups determine their protonation state at a given
pH.
Rationale: The pKa values of ionizable amino-acid groups determine their protonation state at a given pH. Amino-
acid behavior depends on side-chain chemistry, protonation state, pH, and the structure of the alpha-amino-acid
backbone.
6. An amino-acid chemistry problem requires the concept of peptide bond. Which interpretation is
mostaccurate?
A) A peptide bond joins two side chains only
B) A peptide bond is an ester linkage
C) A peptide bond is formed between two phosphate groups
D) A peptide bond is the amide linkage formed between the carboxyl group of one amino acid and the amino
group ofanother.
Correct Answer: A peptide bond is the amide linkage formed between the carboxyl group of one amino acid
and the amino group of another.
Rationale: A peptide bond is the amide linkage formed between the carboxyl group of one amino acid and the amino
group of another. Amino-acid behavior depends on side-chain chemistry, protonation state, pH, and the structure of
the alpha-amino-acid backbone.
7. Which statement best describes tertiary structure in CHEM 210 Module 3?
A) Tertiary structure is unrelated to side-chain interactions
B) Tertiary structure describes amino-acid sequence only
C) Tertiary structure is the overall three-dimensional folding of a single polypeptide chain.
D) Tertiary structure requires multiple polypeptide chains
Correct Answer: Tertiary structure is the overall three-dimensional folding of a single polypeptide chain.
Rationale: Tertiary structure is the overall three-dimensional folding of a single polypeptide chain. This aligns with
Portage Module 3's official focus on the 20 amino acids, peptide bonds, and protein structure-function relationships.
8. An amino-acid chemistry problem requires the concept of zwitterion. Which interpretation is
mostaccurate?
Page 3
CHEM 210 Module 3 Exam | Biochemistry | Portage
| Q & A | 26/27 Actual (PDF)
1. An amino-acid chemistry problem requires the concept of amino acid side chain. Which
interpretation ismost accurate?
A) Amino Acid Side Chain has the opposite biochemical role from the definition given.
B) Amino Acid Side Chain is unrelated to amino acids, peptides, or proteins.
C) The side chain, or R group, determines many chemical properties of an amino acid such as polarity,
charge, andhydrophobicity.
D) Amino Acid Side Chain is determined only by molecular size and not by chemical structure.
Correct Answer: The side chain, or R group, determines many chemical properties of an amino acid such as
polarity, charge, and hydrophobicity.
Rationale: The side chain, or R group, determines many chemical properties of an amino acid such as polarity,
charge, and hydrophobicity. Amino-acid behavior depends on side-chain chemistry, protonation state, pH, and the
structure of the alpha-amino-acid backbone.
2. Which statement best describes cooperative binding in CHEM 210 Module 3?
A) Cooperative binding means ligand binding at one subunit affects ligand affinity at other subunits.
B) Cooperativity occurs only in monomeric proteins
C) Cooperative binding eliminates affinity changes
D) Cooperative binding means each subunit behaves independently
Correct Answer: Cooperative binding means ligand binding at one subunit affects ligand affinity at other
subunits.
Rationale: Cooperative binding means ligand binding at one subunit affects ligand affinity at other subunits. This
aligns with Portage Module 3's official focus on the 20 amino acids, peptide bonds, and protein structure-function
relationships.
3. Which statement best describes amino acid general structure in CHEM 210 Module 3?
A) A standard amino acid contains only an amino group
B) A standard alpha-amino acid contains an amino group, a carboxyl group, a hydrogen, and a variable side
chainattached to the alpha carbon.
C) The side chain is attached to the carboxyl carbon
D) All amino acids lack a carboxyl group
Correct Answer: A standard alpha-amino acid contains an amino group, a carboxyl group, a hydrogen, and a
variable side chain attached to the alpha carbon.
Rationale: A standard alpha-amino acid contains an amino group, a carboxyl group, a hydrogen, and a variable side
chain attached to the alpha carbon. This aligns with Portage Module 3's official focus on the 20 amino acids, peptide
bonds, and protein structure-function relationships.
4. A peptide or secondary-structure question involves peptide N-terminus. Which statement is correct?
A) The N-terminus is always written on the right
B) The N-terminus of a peptide contains the free amino group and is conventionally written on the left.
Page 2
, CHEM 210 | Module 3 | Original Biochemistry Practice
C) The N-terminus is the free carboxyl end
D) The N-terminus contains no nitrogen
Correct Answer: The N-terminus of a peptide contains the free amino group and is conventionally written on
the left.
Rationale: The N-terminus of a peptide contains the free amino group and is conventionally written on the left.
Peptide geometry and backbone hydrogen bonding are central to understanding primary and secondary protein
structure.
5. An amino-acid chemistry problem requires the concept of amino acid pKa. Which interpretation is
mostaccurate?
A) Amino Acid Pka is unrelated to amino acids, peptides, or proteins.
B) Amino Acid Pka has the opposite biochemical role from the definition given.
C) The pKa values of ionizable amino-acid groups determine their protonation state at a given pH.
D) Amino Acid Pka is determined only by molecular size and not by chemical structure.
Correct Answer: The pKa values of ionizable amino-acid groups determine their protonation state at a given
pH.
Rationale: The pKa values of ionizable amino-acid groups determine their protonation state at a given pH. Amino-
acid behavior depends on side-chain chemistry, protonation state, pH, and the structure of the alpha-amino-acid
backbone.
6. An amino-acid chemistry problem requires the concept of peptide bond. Which interpretation is
mostaccurate?
A) A peptide bond joins two side chains only
B) A peptide bond is an ester linkage
C) A peptide bond is formed between two phosphate groups
D) A peptide bond is the amide linkage formed between the carboxyl group of one amino acid and the amino
group ofanother.
Correct Answer: A peptide bond is the amide linkage formed between the carboxyl group of one amino acid
and the amino group of another.
Rationale: A peptide bond is the amide linkage formed between the carboxyl group of one amino acid and the amino
group of another. Amino-acid behavior depends on side-chain chemistry, protonation state, pH, and the structure of
the alpha-amino-acid backbone.
7. Which statement best describes tertiary structure in CHEM 210 Module 3?
A) Tertiary structure is unrelated to side-chain interactions
B) Tertiary structure describes amino-acid sequence only
C) Tertiary structure is the overall three-dimensional folding of a single polypeptide chain.
D) Tertiary structure requires multiple polypeptide chains
Correct Answer: Tertiary structure is the overall three-dimensional folding of a single polypeptide chain.
Rationale: Tertiary structure is the overall three-dimensional folding of a single polypeptide chain. This aligns with
Portage Module 3's official focus on the 20 amino acids, peptide bonds, and protein structure-function relationships.
8. An amino-acid chemistry problem requires the concept of zwitterion. Which interpretation is
mostaccurate?
Page 3
