FINAL EXAMINATION: BIOCHEMISTRY
(TANSEY, 1ST EDITION) QUESTIONS AND
ANSWERS WITH RATIONELS LATEST
UPDATE 2026
Section 1: The Chemical Foundations of Biochemistry (Chapter 1)
Question 1
Which of the following best explains the interactions that occur
between the atoms of water molecules and the ions that form when
sodium chloride dissolves in water?
A) Hydrogens interact with the sodium ion; oxygens interact with the
chloride ion.
B) Hydrogens interact with the chloride ion; oxygens interact with the
sodium ion.
C) Hydrogens interact with both the sodium ion and the chloride ion.
D) Oxygens interact with both the sodium ion and the chloride ion.
Answer: B
Rationale: Water is a polar molecule. The partial negative charge on
the oxygen atom is attracted to the positively charged sodium ion
(Na+Na+). Conversely, the partial positive charges on the hydrogen
atoms are attracted to the negatively charged chloride ion (Cl−Cl−).
This differential interaction is what allows water to effectively
dissolve ionic compounds .
,Question 2
What would be the resulting pH if 1 mL of 1.0 M NaOH was added to
one liter of pure water (assume initial pH 7.0)?
A) 1.0
B) 7.3
C) 11.0
D) 13.0
Answer: C
Rationale: 1 mL of 1.0 M NaOH contains 0.001 moles of OH−OH−. In 1
liter of water, this yields a concentration of 0.001 M OH−OH−,
so pOH=3.0pOH=3.0 (since −log(0.001)=3−log(0.001)=3).
Therefore, pH=14.0−3.0=11.0pH=14.0−3.0=11.0. While small amounts of
strong acid or base have a dramatic effect on unbuffered water, the
pH changes from 7 to 11 .
Question 3
Water’s ability to form extensive hydrogen bonds primarily contributes
to which property essential for life?
A) Low specific heat capacity
B) High heat of vaporization
C) Non-polar solvent properties
D) Low surface tension
Answer: B
Rationale: Hydrogen bonding requires significant energy to overcome.
This results in a high heat of vaporization, allowing organisms to cool
themselves through sweating. It also contributes to a high specific
heat capacity, stabilizing ocean temperatures .
Section 2: Nucleic Acids & Central Dogma (Chapter 2)
, Question 4
Genomic DNA that encodes proteins undergoes the process of _____
to produce _____.
A) translation; proteins
B) transcription; mRNA
C) transcription; rRNA
D) replication; DNA
Answer: B
Rationale: The central dogma of molecular biology states that DNA is
transcribed into RNA (specifically messenger RNA for protein-coding
genes), and that RNA is then translated into protein. The question
specifically asks for the process that encodes proteins from DNA,
which is transcription producing mRNA .
Question 5
Transfer RNA (tRNA) molecules are directly involved in which process?
A) Transcription
B) Translation
C) DNA Replication
D) Reverse Transcription
Answer: B
Rationale: tRNAs function as adaptor molecules during translation
(protein synthesis). They carry specific amino acids to the ribosome
and recognize the corresponding codons on the mRNA through their
anticodon loops. They are not involved in transcription or DNA
replication .
Question 6
Prokaryotes contain nucleotide sequences known as _____ that contain
(TANSEY, 1ST EDITION) QUESTIONS AND
ANSWERS WITH RATIONELS LATEST
UPDATE 2026
Section 1: The Chemical Foundations of Biochemistry (Chapter 1)
Question 1
Which of the following best explains the interactions that occur
between the atoms of water molecules and the ions that form when
sodium chloride dissolves in water?
A) Hydrogens interact with the sodium ion; oxygens interact with the
chloride ion.
B) Hydrogens interact with the chloride ion; oxygens interact with the
sodium ion.
C) Hydrogens interact with both the sodium ion and the chloride ion.
D) Oxygens interact with both the sodium ion and the chloride ion.
Answer: B
Rationale: Water is a polar molecule. The partial negative charge on
the oxygen atom is attracted to the positively charged sodium ion
(Na+Na+). Conversely, the partial positive charges on the hydrogen
atoms are attracted to the negatively charged chloride ion (Cl−Cl−).
This differential interaction is what allows water to effectively
dissolve ionic compounds .
,Question 2
What would be the resulting pH if 1 mL of 1.0 M NaOH was added to
one liter of pure water (assume initial pH 7.0)?
A) 1.0
B) 7.3
C) 11.0
D) 13.0
Answer: C
Rationale: 1 mL of 1.0 M NaOH contains 0.001 moles of OH−OH−. In 1
liter of water, this yields a concentration of 0.001 M OH−OH−,
so pOH=3.0pOH=3.0 (since −log(0.001)=3−log(0.001)=3).
Therefore, pH=14.0−3.0=11.0pH=14.0−3.0=11.0. While small amounts of
strong acid or base have a dramatic effect on unbuffered water, the
pH changes from 7 to 11 .
Question 3
Water’s ability to form extensive hydrogen bonds primarily contributes
to which property essential for life?
A) Low specific heat capacity
B) High heat of vaporization
C) Non-polar solvent properties
D) Low surface tension
Answer: B
Rationale: Hydrogen bonding requires significant energy to overcome.
This results in a high heat of vaporization, allowing organisms to cool
themselves through sweating. It also contributes to a high specific
heat capacity, stabilizing ocean temperatures .
Section 2: Nucleic Acids & Central Dogma (Chapter 2)
, Question 4
Genomic DNA that encodes proteins undergoes the process of _____
to produce _____.
A) translation; proteins
B) transcription; mRNA
C) transcription; rRNA
D) replication; DNA
Answer: B
Rationale: The central dogma of molecular biology states that DNA is
transcribed into RNA (specifically messenger RNA for protein-coding
genes), and that RNA is then translated into protein. The question
specifically asks for the process that encodes proteins from DNA,
which is transcription producing mRNA .
Question 5
Transfer RNA (tRNA) molecules are directly involved in which process?
A) Transcription
B) Translation
C) DNA Replication
D) Reverse Transcription
Answer: B
Rationale: tRNAs function as adaptor molecules during translation
(protein synthesis). They carry specific amino acids to the ribosome
and recognize the corresponding codons on the mRNA through their
anticodon loops. They are not involved in transcription or DNA
replication .
Question 6
Prokaryotes contain nucleotide sequences known as _____ that contain
