AAMC FL 2 CP questions and answers
with solutions 2025
What atom is the site of covalent attachment of AMC to the model tetrapeptide used in the studies?
A. I
B. II
C. III
D. IV - ANSWER A.
The answer is A because AMC is attached to the peptide on the carboxyl side. This suggests that an
amide linkage involving the N atom in AMC is used to covalently attach the flurophore to the peptide.
What expression gives the amount of light energy (in J per photon) that is converted to other forms
between the fluorescence excitation and emission events?
A. (6.62 × 10-34) × (3.0 × 108)
B. (6.62 × 10-34) × (3.0 × 108) × (360 × 10-9)
C. (6.62 × 10-34) × (3.0 × 108) × [1 / (360 × 10-9) - 1 / (440 × 10-9)]
D. (6.62 × 10-34) × (3.0 × 108) / (440 × 10-9) - ANSWER C.
The answer to this question is C because the equation of interest is E=hf=hc/λ, where h=6.62 x 10^-34 J.s
and c=3.0 x10^8 m/s. Excitation occult's at λ=360 nm, but fluorescence is observed at λ=440 nm. This
implies that an energy of E= 6.62 × 10-34) × (3.0 × 108) × [1 / (360 × 10-9) - 1 / (440 × 10-9)] J per photon
is converted to other forms between the excitation and fluorescence events.
Compared to the concentration of proteasome, the concentration of the substrate is larger by what
factor?
A. 5 x 10^1
B. 5 x 10^2
,C. 5 x 10^3
D. 5 x 10^4 - ANSWER D.
The answer to this question is D. The proteasome was present at a concentration of 2 x10^-9 M, while
the substrate was present at 100 x10^-6. The ratio of these two numbers is 5 x 10^4.
What is the total number of sp2 hybridized carbon atoms present in the fluorophore used in
experiments?
A. 4
B. 6
C. 9
D. 10 - ANSWER C.
The fluorophore used in the experiments was AMC. There are 10 carbon atoms in AMC. Nine of these
carbon atoms are AX3 systems that possess exactly one doubly bonded atom and are therefore sp2
hybridized.
Which amino acid is found in the greatest abundance in the active site of laccase?
A. Phe
B. Tyr
C. His
D. Cys - ANSWER C.
The answer to this question is C because the five-membered imidazole rings depicted in Figure 1 are
associated with histidine, an amino acid whose side chain is frequency encountered at the active site of
metalloenzymes.
What is the structure of the product formed with Compound 3 is the substrate of laccase-catalyzed
reaction? - ANSWER D.
, Based on Reaction 1 and the fact that the product of oxidation absorbs strongly in the visible region, the
most likely structure of the product is the highly conjugated quinone that is depicted in structure D.
Based on the data from Table 1, what effects do acid and chloride have on the enzymatic activity of
laccases?
A. Both acid and chloride decrease the activity
B. Both acid and chloride increase the activity
C. Acid decreases the activity, whereas chloride increases the activity
D. Acid increases the activity, whereas chloride decreases the activity - ANSWER D.
Activity increased with lower pH, which corresponds to a higher acidity of the solution, while
introduction of chloride lowered activity dramatically.
The concentration of enzyme for each experiment was 5.0 μM. What is Kcat for the reaction at pH 4.5
with NO chloride added when Compound 3 is the substrate?
A. 2.5 x 10^-2 s-1
B. 1.3 x 10^2 s-1
C. 5.3 x 10^3 s-1
D. 7.0 x 10^5 s-1 - ANSWER A.
The fact that the rate of product formation did not vary over time for the first 5 minutes implies that the
enzyme was saturated with substrate. Under these conditions, kcat = Vmax/[E] = (125 nM/s)/5.0 μM =
2.5 × 10-2 s-1.
Absorption of ultraviolet light by organic molecules always results in what process?
A. Bond breaking
B. Excitation of bound electrons
with solutions 2025
What atom is the site of covalent attachment of AMC to the model tetrapeptide used in the studies?
A. I
B. II
C. III
D. IV - ANSWER A.
The answer is A because AMC is attached to the peptide on the carboxyl side. This suggests that an
amide linkage involving the N atom in AMC is used to covalently attach the flurophore to the peptide.
What expression gives the amount of light energy (in J per photon) that is converted to other forms
between the fluorescence excitation and emission events?
A. (6.62 × 10-34) × (3.0 × 108)
B. (6.62 × 10-34) × (3.0 × 108) × (360 × 10-9)
C. (6.62 × 10-34) × (3.0 × 108) × [1 / (360 × 10-9) - 1 / (440 × 10-9)]
D. (6.62 × 10-34) × (3.0 × 108) / (440 × 10-9) - ANSWER C.
The answer to this question is C because the equation of interest is E=hf=hc/λ, where h=6.62 x 10^-34 J.s
and c=3.0 x10^8 m/s. Excitation occult's at λ=360 nm, but fluorescence is observed at λ=440 nm. This
implies that an energy of E= 6.62 × 10-34) × (3.0 × 108) × [1 / (360 × 10-9) - 1 / (440 × 10-9)] J per photon
is converted to other forms between the excitation and fluorescence events.
Compared to the concentration of proteasome, the concentration of the substrate is larger by what
factor?
A. 5 x 10^1
B. 5 x 10^2
,C. 5 x 10^3
D. 5 x 10^4 - ANSWER D.
The answer to this question is D. The proteasome was present at a concentration of 2 x10^-9 M, while
the substrate was present at 100 x10^-6. The ratio of these two numbers is 5 x 10^4.
What is the total number of sp2 hybridized carbon atoms present in the fluorophore used in
experiments?
A. 4
B. 6
C. 9
D. 10 - ANSWER C.
The fluorophore used in the experiments was AMC. There are 10 carbon atoms in AMC. Nine of these
carbon atoms are AX3 systems that possess exactly one doubly bonded atom and are therefore sp2
hybridized.
Which amino acid is found in the greatest abundance in the active site of laccase?
A. Phe
B. Tyr
C. His
D. Cys - ANSWER C.
The answer to this question is C because the five-membered imidazole rings depicted in Figure 1 are
associated with histidine, an amino acid whose side chain is frequency encountered at the active site of
metalloenzymes.
What is the structure of the product formed with Compound 3 is the substrate of laccase-catalyzed
reaction? - ANSWER D.
, Based on Reaction 1 and the fact that the product of oxidation absorbs strongly in the visible region, the
most likely structure of the product is the highly conjugated quinone that is depicted in structure D.
Based on the data from Table 1, what effects do acid and chloride have on the enzymatic activity of
laccases?
A. Both acid and chloride decrease the activity
B. Both acid and chloride increase the activity
C. Acid decreases the activity, whereas chloride increases the activity
D. Acid increases the activity, whereas chloride decreases the activity - ANSWER D.
Activity increased with lower pH, which corresponds to a higher acidity of the solution, while
introduction of chloride lowered activity dramatically.
The concentration of enzyme for each experiment was 5.0 μM. What is Kcat for the reaction at pH 4.5
with NO chloride added when Compound 3 is the substrate?
A. 2.5 x 10^-2 s-1
B. 1.3 x 10^2 s-1
C. 5.3 x 10^3 s-1
D. 7.0 x 10^5 s-1 - ANSWER A.
The fact that the rate of product formation did not vary over time for the first 5 minutes implies that the
enzyme was saturated with substrate. Under these conditions, kcat = Vmax/[E] = (125 nM/s)/5.0 μM =
2.5 × 10-2 s-1.
Absorption of ultraviolet light by organic molecules always results in what process?
A. Bond breaking
B. Excitation of bound electrons
