AAMC Bundle Online Practice MCAT Exam
Questions and Answers with Rationales
(Latest Update 2024)
Which wavelength of laser light can be used with the
photodiode detector in the atomic force microscope?
(A) 226 nm
(B) 633 nm
(C) 1.26 μm
(D) 3.17 μm - Correct Answers ✅(B) The wavelength of
visible light is between about 400 to 750 nm. Red light in
particular ranges from 620-750 nm. Helium-neon red lasers
operate at 633 nm. Therefore, the only possible answer is B.
WIMI: Didn't know what was being asked... oops.
(A) This wavelength corresponds to radiation in the ultraviolet
range of the electromagnetic spectrum.
(C) This wavelength corresponds to radiation in the infrared
range of the electromagnetic spectrum.
(D) This wavelength corresponds to radiation in the infrared
range of the electromagnetic spectrum.
What is the mechanical work done by the cantilever when the
extension increases from 10 nm to 15 nm, and the force is
increased steadily from 0 pN to 100 pN?
(A) 2.00 x 10^-22
(B) 4.70 x 10^-20
(C) 2.50 x 10^-19
,AAMC Bundle Online Practice MCAT Exam
Questions and Answers with Rationales
(Latest Update 2024)
(D) 5.00 x 10^-18 - Correct Answers ✅(C) This question
requires you to apply the graphical method of calculating the
work done by a variable force, namely the elastic force, W =
(ks)x^2/2. Mechanical work by an elastic force is W =
(ks)x^2/2 = Fx/2. Graphically, it is the area under the force-
extension graph between the corresponding data points.
From Figure 2, the correct response is {[(100 - 0) × 10^-12]N
×[(15 - 10) × 10^-9]m}/2 = 2.50 × 10^-19 J.
WIMI: Did not divide by 2; also messed up scientific notation.
What is the mechanical power exerted on the protein when
the retraction speed is 1000 nm/s and the applied force is 75
pN?
(A) 1.5 × 10^-18 W
(B) 7.5 × 10^-17 W
(C) 3.5 × 10^-6 W
(D) 5.5 × 10^6 W - Correct Answers ✅(B) Power at
constant speed is related to the applied force as P = F × v.
From Figure 3, P = 75 pN × 1000 nm/s = 7.5 × 10^-17 W.
A compound mimics a membrane symport. In an experiment
consisting of a central organic phase that separates two
aqueous "IN" and "OUT phases, the compound remains
mainly confined to the central phase. This is because it is:
(A) hydrophilic with only polar groups
,AAMC Bundle Online Practice MCAT Exam
Questions and Answers with Rationales
(Latest Update 2024)
(B) hydrophilic with both polar and nonpolar groups
(C) lipophilic with only nonpolar groups
(D) lipophilic with both polar and nonpolar groups - Correct
Answers ✅(D) The mimics a membrane symport. Thus, it is
lipophilic. The structure has both polar and nonpolar groups.
WIMI: Did not recognize the structure of the experiment, and
the fact that the compound is confined to the organic layer.
(A) The central phase is organic and separate from the
aqueous phases on either side. This implies that solutes
confined to it are lipophilic (hydrophobic).
(B) The central phase is organic and separate from the
aqueous phases on either side. This implies that solutes
confined to it are lipophilic (hydrophobic).
(C) The compound must contain both polar and non-polar
groups in order to function as an ion transporter in a
hydrophobic phase.
In phosphatidylethanolamine (PE), the C3 carbon is attached
to phosphate ethanolamine, and the C1 and C2 carbons are
attached to COOR1 and COOR1 groups, respectively. What is
a possible structure for either R1 or R2 of ethanolamine?
(A) CH3
(B) NH2
(C) (CH2)15CH3
, AAMC Bundle Online Practice MCAT Exam
Questions and Answers with Rationales
(Latest Update 2024)
(D (CH2O)10CH3 - Correct Answers ✅(C) Because PE is a
lipid, the R groups must represent the acyl chains.
WIMI: Confused reactant PE with TNBS.
(A) Methyl is not sufficiently long to be part of a
phosphatadylethanolamine.
(B) If R were NH2 the group would not be a fatty acid acyl
chain.
(D)The acyl chains of PE molecules do not contain oxygen
atoms.
The hardness ions described in the passage are:
(A) alkaline earth metals.
(B) strongly acidic cations.
(C) formed in nature by reduction of other cations.
(D) derived from atoms upon loss of two electrons. - Correct
Answers ✅(D) All the ions described in the passage have a
+2 charge, meaning they lost two electrons.
WIMI:
(A) Fe2+ is a transition metal cation.
(B) None of the cations mentioned are strongly acidic. Small,
highly charged cations such as Al3+ are strongly acidic.
Questions and Answers with Rationales
(Latest Update 2024)
Which wavelength of laser light can be used with the
photodiode detector in the atomic force microscope?
(A) 226 nm
(B) 633 nm
(C) 1.26 μm
(D) 3.17 μm - Correct Answers ✅(B) The wavelength of
visible light is between about 400 to 750 nm. Red light in
particular ranges from 620-750 nm. Helium-neon red lasers
operate at 633 nm. Therefore, the only possible answer is B.
WIMI: Didn't know what was being asked... oops.
(A) This wavelength corresponds to radiation in the ultraviolet
range of the electromagnetic spectrum.
(C) This wavelength corresponds to radiation in the infrared
range of the electromagnetic spectrum.
(D) This wavelength corresponds to radiation in the infrared
range of the electromagnetic spectrum.
What is the mechanical work done by the cantilever when the
extension increases from 10 nm to 15 nm, and the force is
increased steadily from 0 pN to 100 pN?
(A) 2.00 x 10^-22
(B) 4.70 x 10^-20
(C) 2.50 x 10^-19
,AAMC Bundle Online Practice MCAT Exam
Questions and Answers with Rationales
(Latest Update 2024)
(D) 5.00 x 10^-18 - Correct Answers ✅(C) This question
requires you to apply the graphical method of calculating the
work done by a variable force, namely the elastic force, W =
(ks)x^2/2. Mechanical work by an elastic force is W =
(ks)x^2/2 = Fx/2. Graphically, it is the area under the force-
extension graph between the corresponding data points.
From Figure 2, the correct response is {[(100 - 0) × 10^-12]N
×[(15 - 10) × 10^-9]m}/2 = 2.50 × 10^-19 J.
WIMI: Did not divide by 2; also messed up scientific notation.
What is the mechanical power exerted on the protein when
the retraction speed is 1000 nm/s and the applied force is 75
pN?
(A) 1.5 × 10^-18 W
(B) 7.5 × 10^-17 W
(C) 3.5 × 10^-6 W
(D) 5.5 × 10^6 W - Correct Answers ✅(B) Power at
constant speed is related to the applied force as P = F × v.
From Figure 3, P = 75 pN × 1000 nm/s = 7.5 × 10^-17 W.
A compound mimics a membrane symport. In an experiment
consisting of a central organic phase that separates two
aqueous "IN" and "OUT phases, the compound remains
mainly confined to the central phase. This is because it is:
(A) hydrophilic with only polar groups
,AAMC Bundle Online Practice MCAT Exam
Questions and Answers with Rationales
(Latest Update 2024)
(B) hydrophilic with both polar and nonpolar groups
(C) lipophilic with only nonpolar groups
(D) lipophilic with both polar and nonpolar groups - Correct
Answers ✅(D) The mimics a membrane symport. Thus, it is
lipophilic. The structure has both polar and nonpolar groups.
WIMI: Did not recognize the structure of the experiment, and
the fact that the compound is confined to the organic layer.
(A) The central phase is organic and separate from the
aqueous phases on either side. This implies that solutes
confined to it are lipophilic (hydrophobic).
(B) The central phase is organic and separate from the
aqueous phases on either side. This implies that solutes
confined to it are lipophilic (hydrophobic).
(C) The compound must contain both polar and non-polar
groups in order to function as an ion transporter in a
hydrophobic phase.
In phosphatidylethanolamine (PE), the C3 carbon is attached
to phosphate ethanolamine, and the C1 and C2 carbons are
attached to COOR1 and COOR1 groups, respectively. What is
a possible structure for either R1 or R2 of ethanolamine?
(A) CH3
(B) NH2
(C) (CH2)15CH3
, AAMC Bundle Online Practice MCAT Exam
Questions and Answers with Rationales
(Latest Update 2024)
(D (CH2O)10CH3 - Correct Answers ✅(C) Because PE is a
lipid, the R groups must represent the acyl chains.
WIMI: Confused reactant PE with TNBS.
(A) Methyl is not sufficiently long to be part of a
phosphatadylethanolamine.
(B) If R were NH2 the group would not be a fatty acid acyl
chain.
(D)The acyl chains of PE molecules do not contain oxygen
atoms.
The hardness ions described in the passage are:
(A) alkaline earth metals.
(B) strongly acidic cations.
(C) formed in nature by reduction of other cations.
(D) derived from atoms upon loss of two electrons. - Correct
Answers ✅(D) All the ions described in the passage have a
+2 charge, meaning they lost two electrons.
WIMI:
(A) Fe2+ is a transition metal cation.
(B) None of the cations mentioned are strongly acidic. Small,
highly charged cations such as Al3+ are strongly acidic.
