AAMC MCAT Practice Exam 2
AAMC MCAT PRACTICE EXAM 2 NEWEST 2025/2026 COMPLETE
ALL 200 QUESTIONS AND CORRECT DETAILED ANSWERS
|ALREADY GRADED A+||ALREADY GRADED A+
C/P: A person is sitting in a chair. Why must the person either lean forward or slide
their feet under the chair in order to stand up?
A) to increase the force required to stand up
B) to use the friction with the ground
C) to reduce the energy required to stand up
D) to keep the body in equilibrium while rising
D) to keep the body in equilibrium while rising
The answer to this question is D because as the person is attempting to stand, the
only support comes from the feet on the ground. The person is in equilibrium only
when the center of mass is directly above their feet. Otherwise, if the person did
not lean forward or slide the feet under the chair, the person would fall backward
due to the large torque created by the combination of the weight of the body
(applied at the person's center of mass) and the distance along the horizontal
between the center of mass and the support point.
C/P: The side chain of tryptophan will give rise to the largest CD signal in the near
UV region when:
A) present as a free amino acid
B) part of an a-helix
C) part of a B-sheet
D) part of a fully folded protein
D) part of a fully folded protein
The answer to this question is D because tryptophan has an aromatic side chain
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, AAMC MCAT Practice Exam 2
that will give rise to a significant CD signal in the near UV region if it is found in a
fully folded protein.
C/P: Which amino acid will contribute to the CD signal in the far UV region, but
NOT the near UV region, when part of a fully folded protein?
"Asymmetry resulting from tertiary structural features causes the largest increase
in CD signal intensity in the near UV region of peptides. The side chains of amino
acid residues absorb in this region.
The peptide bond absorbs in the far UV region (190-250 nm). The CD signals of
these bonds are dramatically impacted by their proximity to secondary structural
elements."
A) Trp
B) Phe
C) Ala
D) Tyr
C) Ala
C/P: Based on the relative energy of the absorbed electromagnetic radiation,
which absorber, a peptide bond or an aromatic side chain, exhibits an electronic
excited state that is closer in energy to the ground state?
"Asymmetry resulting from tertiary structural features causes the largest increase
in CD signal intensity in the near UV region of peptides. The side chains of amino
acid residues absorb in this region.
The peptide bond absorbs in the far UV region (190-250 nm). The CD signals of
these bonds are dramatically impacted by their proximity to secondary structural
elements."
A) An aromatic side chain; the absorbed photon energy is higher.
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, AAMC MCAT Practice Exam 2
B) An aromatic side chain; the absorbed photon energy is lower.
C) A peptide bond; the absorbed photon energy is higher.
D) A peptide bond; the absorbed photon energy is lower.
B) An aromatic side chain; the absorbed photon energy is lower.
The answer to this question is B because aromatic side chains absorb in the near
UV region of the electromagnetic spectrum, which has longer wavelengths, and
hence lower energy, than peptide bonds. Because the energy of the photon
matches the energy gap between the ground and the excited state, this implies
that the aromatic side chain has more closely spaced energy levels.
C/P: What is the net charge of sT-loop at pH 7.2?
"A synthetic peptide with the amino acid sequence KTFCGPEYLA was generated as
a mimic of the T-loop. This synthetic T-loop (sT-loop) was incubated with 32P-
labeled ATP in the presence of PDK1 for different time periods at 37 ° C and pH
7.2, and the amount of radioactivity incorporated into sT-loop was measured by
detection of β- decay."
A) -2
B) -1
C) 0
D) +1
C) 0
The answer to this question is C because at pH 7.2, the N-terminus will be
positively charged and the C-terminus will be negatively charged. In addition, the
lysine side chain will carry one positive charge and the glutamic acid side chain
will carry one negative charge.
C/P: In designing the experiment, the researchers used which type of P-32 labeled
ATP?
A) aP32-ATP
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, AAMC MCAT Practice Exam 2
B) BP32-ATP
C) γP32-ATP
D) δP-32 ATP
D) δP-32 ATP
The answer to this question is C because the phosphoryl transfer from kinases
comes from the γ-phosphate of ATP. Therefore, the experiment should require
γ32P-ATP.
C/P: When used in place of spHM, which peptide would be most likely to achieve
the same experimental results?
"This experiment was repeated in the presence of a synthetic peptide that mimics
the HM domain (sHM) of Ser/Thr kinases with the amino acid sequence FLGFTY.
Phosphorylated sHM (spHM) was also used in place of sHM."
A) FLGFAY
B) FLGFQY
C) FLGFGY
D) FLGFEY
D) FLGFEY
The answer to this question is D because the phosphorylated threonine would
most likely be mimicked by glutamic acid in terms of size and charge.
C/P: Based on the information in the passage, PDK1 catalyzes the addition of
phosphate to what functional group?
"This experiment was repeated in the presence of a synthetic peptide that mimics
the HM domain (sHM) of Ser/Thr kinases with the amino acid sequence FLGFTY.
Phosphorylated sHM (spHM) was also used in place of sHM."
A) Hydroxyl
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AAMC MCAT PRACTICE EXAM 2 NEWEST 2025/2026 COMPLETE
ALL 200 QUESTIONS AND CORRECT DETAILED ANSWERS
|ALREADY GRADED A+||ALREADY GRADED A+
C/P: A person is sitting in a chair. Why must the person either lean forward or slide
their feet under the chair in order to stand up?
A) to increase the force required to stand up
B) to use the friction with the ground
C) to reduce the energy required to stand up
D) to keep the body in equilibrium while rising
D) to keep the body in equilibrium while rising
The answer to this question is D because as the person is attempting to stand, the
only support comes from the feet on the ground. The person is in equilibrium only
when the center of mass is directly above their feet. Otherwise, if the person did
not lean forward or slide the feet under the chair, the person would fall backward
due to the large torque created by the combination of the weight of the body
(applied at the person's center of mass) and the distance along the horizontal
between the center of mass and the support point.
C/P: The side chain of tryptophan will give rise to the largest CD signal in the near
UV region when:
A) present as a free amino acid
B) part of an a-helix
C) part of a B-sheet
D) part of a fully folded protein
D) part of a fully folded protein
The answer to this question is D because tryptophan has an aromatic side chain
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, AAMC MCAT Practice Exam 2
that will give rise to a significant CD signal in the near UV region if it is found in a
fully folded protein.
C/P: Which amino acid will contribute to the CD signal in the far UV region, but
NOT the near UV region, when part of a fully folded protein?
"Asymmetry resulting from tertiary structural features causes the largest increase
in CD signal intensity in the near UV region of peptides. The side chains of amino
acid residues absorb in this region.
The peptide bond absorbs in the far UV region (190-250 nm). The CD signals of
these bonds are dramatically impacted by their proximity to secondary structural
elements."
A) Trp
B) Phe
C) Ala
D) Tyr
C) Ala
C/P: Based on the relative energy of the absorbed electromagnetic radiation,
which absorber, a peptide bond or an aromatic side chain, exhibits an electronic
excited state that is closer in energy to the ground state?
"Asymmetry resulting from tertiary structural features causes the largest increase
in CD signal intensity in the near UV region of peptides. The side chains of amino
acid residues absorb in this region.
The peptide bond absorbs in the far UV region (190-250 nm). The CD signals of
these bonds are dramatically impacted by their proximity to secondary structural
elements."
A) An aromatic side chain; the absorbed photon energy is higher.
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, AAMC MCAT Practice Exam 2
B) An aromatic side chain; the absorbed photon energy is lower.
C) A peptide bond; the absorbed photon energy is higher.
D) A peptide bond; the absorbed photon energy is lower.
B) An aromatic side chain; the absorbed photon energy is lower.
The answer to this question is B because aromatic side chains absorb in the near
UV region of the electromagnetic spectrum, which has longer wavelengths, and
hence lower energy, than peptide bonds. Because the energy of the photon
matches the energy gap between the ground and the excited state, this implies
that the aromatic side chain has more closely spaced energy levels.
C/P: What is the net charge of sT-loop at pH 7.2?
"A synthetic peptide with the amino acid sequence KTFCGPEYLA was generated as
a mimic of the T-loop. This synthetic T-loop (sT-loop) was incubated with 32P-
labeled ATP in the presence of PDK1 for different time periods at 37 ° C and pH
7.2, and the amount of radioactivity incorporated into sT-loop was measured by
detection of β- decay."
A) -2
B) -1
C) 0
D) +1
C) 0
The answer to this question is C because at pH 7.2, the N-terminus will be
positively charged and the C-terminus will be negatively charged. In addition, the
lysine side chain will carry one positive charge and the glutamic acid side chain
will carry one negative charge.
C/P: In designing the experiment, the researchers used which type of P-32 labeled
ATP?
A) aP32-ATP
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, AAMC MCAT Practice Exam 2
B) BP32-ATP
C) γP32-ATP
D) δP-32 ATP
D) δP-32 ATP
The answer to this question is C because the phosphoryl transfer from kinases
comes from the γ-phosphate of ATP. Therefore, the experiment should require
γ32P-ATP.
C/P: When used in place of spHM, which peptide would be most likely to achieve
the same experimental results?
"This experiment was repeated in the presence of a synthetic peptide that mimics
the HM domain (sHM) of Ser/Thr kinases with the amino acid sequence FLGFTY.
Phosphorylated sHM (spHM) was also used in place of sHM."
A) FLGFAY
B) FLGFQY
C) FLGFGY
D) FLGFEY
D) FLGFEY
The answer to this question is D because the phosphorylated threonine would
most likely be mimicked by glutamic acid in terms of size and charge.
C/P: Based on the information in the passage, PDK1 catalyzes the addition of
phosphate to what functional group?
"This experiment was repeated in the presence of a synthetic peptide that mimics
the HM domain (sHM) of Ser/Thr kinases with the amino acid sequence FLGFTY.
Phosphorylated sHM (spHM) was also used in place of sHM."
A) Hydroxyl
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