AAMC FL 4 CP

What is the MAP of a person whose blood pressure is 135/90 mmHg? A. 85 mmHg B. 90 mmHg C. 105 mmHg D. 110 mmHg

105 top number: systolic = 135 bottom number: diastolic (down) = 90

Which forms of guanine and thymine are favored under physiological conditions? A. The keto form of guanine and the keto form of thymine B. The keto form of guanine and the enol form of thymine C. The enol form of guanine and the keto form of thymine D. The enol form of guanine and the enol form of thymine

keto form is the most stable form therefore it is more favorable

Which is more stable? keto or enol

keto! because the C=O on keto is more common/stable compared to enol C=C

What is the effect produced by the PRK technique designed to correct nearsightedness? A. The density of the cornea is increased. B. The radius of curvature of the cornea is increased. C. The index of refraction of the cornea is increased. D. The thickness of the cornea at the apex is increased. Passage: "To correct nearsightedness, the laser beam is directed onto the central part of the cornea, resulting in a flattening of the cornea"

keyword: flattening of the cornea --> radius of curve of cornea is increased

If a thin thread is placed between a screen and a bright source of light, a pattern of parallel dark and bright fringes appears on the screen. The phenomenon best explaining the formation of this pattern is: A. refraction. B. polarization. C. diffraction. D. reflection.

keyword: parallel dark and bright fringes diffraction! bc narrow slits

Compound 3 is prepared from Compound 2 (Figure 2) by: A. reduction of the ketone and lactonization of the gamma-hydroxyester. B. hydrolysis of one ester and formation of an acetal from the ketoacid. C. reduction of one ester and formation of an acetal from the gamma-hydroxyketone. D. reduction of one ester and the ketone followed by dehydration to a ketoether.

lactone!!! (I just identified the lactone hehe) to give more context, we see that ketone gained something (reduced) during it's cyclization

If methane (CH4) were substituted for NH3 in the aluminum can, the crushing of the can would: A. occur because CH4, being polar, would dissolve in the water in the tray. B. occur because CH4, being nonpolar, would dissolve in the water in the tray. C. not occur because CH4, being polar, would not dissolve in the water in the tray. D. not occur because CH4, being nonpolar, would not dissolve in the water in the tray.

methane has no sense of polarity (CH4) all equal therefore it's nonpolar eliminate A and B since it's nonpolar, it would not dissolve in water so D!

carbamate

nitrogen on the other side of O of the ester group

Based on the reaction scheme in Figure 1, what is the mechanism of substrate binding to RT? Passage: "inhibitor binding to RT, RT with bound RNA template (TP), and the RT/TP/dNTP complex"

ordered!

What is the [H3O+] in the solution used in the experiment done at the lowest pH? A. 0.01 μM B. 0.1 μM C. 1.0 μM D. 100 μM

pH = -log (H3O+) plug in and solve

What is the approximate energy of a photon in the absorbed radiation that yielded the data in Table 1? (Note: Use 1 eV = 1.6 × 10-19 J and hc = 19.8 × 10-26 J•m.) A. 1 eV B. 2 eV C. 3 eV D. 4 eV

plug it into E=hc/lambda, then divide it by the 1eV conversion 2 eV

The use of pulsed laser radiation in the PRK procedure, as opposed to continuous laser radiation, allows the cornea to: A. absorb more radiation. B. change its index of refraction. C. increase the area exposed to radiation. D. maintain a lower average temperature.

pulsed laser radiation vs continuous laser radiation pulse is able to pause, therefore there is less strain/heat generated therefore: D! maintain a lower average temperature

During Reaction 2, did the oxidation state of N change? A. Yes; it changed from -3 to -4. B. Yes; it changed from 0 to +1. C. No; it remained at -3. D. No; it remained at +1.

remember how to find the oxidation state! hint, for the ion you're trying to find, have that has the X variable! NH3 (x) + (3) = 0 x =-3 NH4+ x + (4) = +1 x = -3

How many π-bonds do compounds 1 and 3 have? A. Both compounds 1 and 3 have 6 π-bonds. B. Compound 1 has 6 π-bonds, and Compound 3 has 7 π-bonds. C. Both compounds 1 and 3 have 7 π-bonds. D. Compound 1 has 5 π-bonds, and Compound 3 has 7 π-bonds.

remember the sigma pi chart!! compound 1: 6 pi compound 3: 7 pi B is correct

Suppose a blood sample tested above the range (6.0 mg/dL) of the standards used in the experiment. What modification will provide a more precise reading by data interpolation as opposed to extrapolation using the same standards? A. Increase the enzyme concentration. B. Increase the oxygen pressure. C. Decrease the content of oxygen acceptor. D. Dilute the sample with additional solvent.

since the test sample is able normal range, we can simply just dilute it so we can use it bc now the glucose concentration is now in acceptable rang D: dilute the sample with additional solvent!! *note, you cannot do this for a buffer tho*

saponification

soap formation ester hydrolysis of triacylglycerols using a strong base

sublimation

solid to gas (endothermic)

capacitor

store free electrons on the surface. the electric field produce inside the conductor exactly cancels any external electric field

What allows small insects to walk on the free surface of water? A. Hydrostatic pressure B. Viscosity C. Buoyancy D. Surface tension

surface tension! due to cohesion

double displacement reaction

the ions of two compounds exchange places in an aqueous solution to form two new compounds AB + CD -> AD + CB

What is the frequency of the pulses that deliver laser radiation to the cornea? A. 0.4 Hz B. 4.0 Hz C. 25 Hz D. 250 Hz Passage: "pulsed laser radiation at time intervals of 250 ms"

time intervals = periods! pulse periods use: T = 1/f 1/250 x 10^-3 = 4 Hz

Which of the following compounds is most likely the intermediate product formed in Step 4 of Figure 2 if four equivalents of base are used?

when four equivalent of base (-OH) are used --> 4 potential nucleophilic rxn can occur only 2 were needed in this reaction 1. OH- attack carbonyl to open lactone ring 2. OH- attack carbamate group

When limestone is heated during Step 1, an equilibrium is established. Which of the following expressions is the equilibrium constant for the decomposition of limestone? A. [CaO] B. [CaCO3] C. [CO2] D. [CaO] × [CaCO3]

when writing Keq, NEVER include solids or liquids in the equation only include aq or gas Keq = [product]/[reactant]

Which saturated fatty acid is the most soluble in water? A. CH3(CH2)10COOH B. CH3(CH2)12COOH C. CH3(CH2)14COOH D. CH3(CH2)16COOH

whichever has the least hydrocarbons! A

absorbance equation (beer's law)

A = εbc A= absorbance ε = molar absorptivity b = path length (1 cm) c = concentration B IS SUPPOSE TO BE IN CM

lactam

A cyclic amide

imine

A double bond between a carbon and a nitrogen

Which of the following oxidative transformations is unlikely to occur? A. A primary alcohol to an aldehyde B. A tertiary alcohol to a ketone C. An aldehyde to a carboxylic acid D. A secondary alcohol to a ketone

A: yes (PCC) B: C: yes (H2CrO4) D: yes (Na2Cr2O7, H2SO4, PCC) or if you think kinda logically, usually the most sterically hindered one would be the most difficult to occur.

Based on the information in the passage, which description of an enzyme-substrate covalent intermediate is most likely correct? The substrate is covalently attached to: A. Asp14 through the phosphorus atom of the phosphate group. B. Asp14 through the oxygen atom of the phosphate group. C. Asp16 through the phosphorus atom of the phosphate group. D. Asp16 through the oxygen atom of the phosphate group.

Asp14 = nucleophile nucleophile attacks electrophile and creates a new covalent bond nucleophile (negative) they attack positively charged things Oxygen is always nucleophile therefore the nucleophile Asp14 has to be attacking the phosphorus not the oxygen group

If all of Gas X (from Step 6) is held in a sealed chamber at STP, what will be its approximate volume? A. 22.4 L B. 44.8 L C. 67.2 L D. 89.6 L

1 mol = 22.4 L

An unknown amount of a radioactive isotope with a half-life of 2.0 h was observed for 6.0 h. If the amount of the isotope remaining after 6.0 h was 24 g, what would the original amount have been? A. 3 g B. 4 g C. 144 g D. 192 g

3 half lives in between 2.0 h and 6.0h (1/2) x (1/2) x (1/2) = 1/8 since we want to know that starting amount we would do 8 x 24 = 192 g

What is the approximate concentration of reaction product in a solution that has an absorbance of 0.7 at pH 6.0? A. 0.50 μM B. 500 μM C. 5 mM D. 500 mM

500 micro M

Assume that cellular uptake rates and drug delivery rates of compounds 1 and 2 are identical. If the proposed mechanism of sensitization by Compound 1 is correct, what cancer cell treatment protocol is most likely to produce the most apoptosis 20 h after treatment? A. Administration of both Compound 1 and Compound 2 simultaneously B. Administration of Compound 1 followed by Compound 2 after 0.5 h C. Administration of Compound 2 followed by Compound 1 after 0.5 h D. Administration of Compound 2 followed by Compound 1 after 1 d

B!! ez question

Based on the data in Table 1, what are the effects of increasing pH on catalytic efficiency and the maximum velocity of the reaction? A. Both the catalytic efficiency and the maximum velocity of the reaction increase. B. The catalytic efficiency increases with pH, but the maximum velocity of the reaction decreases. C. The catalytic efficiency decreases with pH, but the maximum velocity of the reaction increases. D. Both the catalytic efficiency and the maximum velocity of the reaction decrease.

Both the catalytic efficiency and velocity max of the reaction decreases

Given that Tris has a pKa of 8.07, for how many of the experiments would Tris have been an acceptable buffer? A. None of the experiments B. Only 1 of the experiments C. Only 2 of the experiments D. All three of the experiments

C!

How many hydrogen bonds are present in the two types of G•T mismatches discussed in the passage? A. 2 in the wobble pair, 2 in the enol T mismatch B. 3 in the wobble pair, 2 in the enol T mismatch C. 2 in the wobble pair, 3 in the enol T mismatch D. 3 in the wobble pair, 3 in the enol T mismatch Passage: In the wobble base pair, the G•T mismatch appears as an offset A•T base pair. In addition, the G•T mismatch can mimic a G•C base pair if the enol tautomer of T is present.

C!

enamine

C=C-NR2

A carbonyl group contains what type of bonding interaction(s) between the C and O atoms? A. One σ only B. One σ and one π only C. One π only D. One σ and two π only

C=O has a double bond 1 sigma 1 pi (B)

Which variant of DNA polymerase will most likely retain catalytic activity? A. D429A B. D429E C. D429K D. D429F

DNA polymerase removes RNA primer to place DNA proofread B! goes from D to E, both are still acidic no change

One company sells a defibrillator for home use that uses a 9-volt DC battery. The battery is rated at 4.2 A•hr (amp•hour). Roughly how much charge can the battery deliver? A. 4.2 C B. 38 C C. 15,000 C D. 136,000 C

I = Q/T where I is current, Q is charge, and T is time Q = I x T Q = (4.2 A hr) x (3600s/1 hr) = 15,000 therefore C is the correct answer

According to the IUPAC, what is the systematic name for the hydrocarbon shown? A. Z-3-methylpent-2-ene B. E-3-methylpent-2-ene C. Z-3-ethylbut-2-ene D. E-3-ethylbut-2-ene

IUPAC RULES 1. longest chain = parent chain 2. give substituents the lowest # Z and E configuration highest priority groups are... Z is same side of double bond E is opposite side of double bond Z-3-methylpent-2-ene

Compared to treatment with Compound 2 alone, which cell line shows the greatest enhancement of chemotherapeutic activity as a result of sensitization by Compound 1? A. Acute leukemia B. Fibrosarcoma C. Cervical carcinoma D. Noncancerous fibroblast Passage: "CC95 indicates the concentration to induce apoptosis in 95% of the cells after 48 hours"

Keyword: CC95 = conc need to induce apoptosis greatest enhancement of chemo activity therefore we are looking for the lowest number! acute leukemia!! **keep in mind of the units too*** acute leukemia is the only one in nanos all the others are in micro.

Based on the information in the passage, compounds 1-3 are what type of inhibitor? A. Competitive B. Mixed C. Product D. Irreversible Passage: "Compounds 1-3 bind to a site on RT that is not the active site, and the binding can occur during any stage of substrate binding."

Keywords: bind not to active site, binding can occur at any stage MIXED

Which conclusion can be drawn from the experimental results described in the passage? A. Compound 1 selectively sensitizes cancer cells to chemotherapeutic action by Compound 2. B. Compound 1 sensitizes all cells to chemotherapeutic action. C. Compound 2 induces apoptosis in cancer cells only in conjunction with treatment with Compound 1. D. Compound 2 inhibits the NF-κB signaling pathway, which leads to apoptosis.

Looking at the graph, we see that compound 1 is not that effective by itself BUT, with compound 1 + 2 its WAYYY more effective compound 2 is effective, but not as effective compared to compound 1 + 2 A!

amine

NH2 NO DOUBLE BOND

amide

NH2 + carbonyl

The intermolecular forces that exist among the molecules of NH3 gas are: A. dipole-dipole forces only. B. London dispersion forces only. C. both dipole-dipole and London dispersion forces. D. neither dipole-dipole nor London dispersion forces.

NH3 is nucleophile H2O is also nucleophile C! both dipole dipole & london dispersion forces

The Na2CO3 used in Step 5 of Figure 3 is necessary to: A. dissolve the bromoester. B. remove an α-hydrogen from the bromoester. C. convert the ammonium salt in Compound 4 to the amine. D. replace the chloride ion in Compound 4 with the carbonate ion.

Na2CO3 is a base (bronsted with this context because we see that it exchanges H+) bronsted base -> accepts H+ so Na2CO3 wants to take a H+ from a structure most likely answer is C!! ammonium salt -> 1 H+ is removed -> becomes amine (NH2)

The UV-VIS spectrophotometer used by the researchers contained a detector that had low sensitivity and was unable to measure high absorbance samples. Which approach to the experiment makes the most sense with this limitation in mind? A. The experiments done at high pH should be diluted relative to those at low pH, or the path length of the high pH experiments should be decreased. B. The experiments done at low pH should be diluted relative to those at high pH, or the path length of the high pH experiments should be decreased. C. The experiments done at high pH should be diluted relative to those at low pH, or the path length of the low pH experiments should be decreased. D. The experiments done at low pH should be diluted relative to those at high pH, or the path length of the low pH experiments should be decreased.

Problem: unable to measure high absorbances therefore we need to use: A=ebc b = ? e (pH) = ? , where b or e needs to decrease and other increase at high pH, absorbance need to decrease since you cannot change the e at pH , you can only change the concentration/path length A!

The specific heat of liquid water is 4.2 kJ/°C•kg. How much energy does it take to heat 2 kg of water from 20°C to 70°C? A. 220 kJ B. 320 kJ C. 420 kJ D. 520 kJ

Q=mcT you dont have to do unit conversions as seen in the specific heat units just plug in the numbers Q = (2) x (4.2) x (50) = 400 ==== C!

Suppose a defibrillator successfully returns a baby's heart to normal beating. Suppose further that 20 g of blood enters the heart at 25 cm/s and leaves 0.10 s later at 35 cm/s. What is the estimated average force on the 20 g of blood as it moves through the baby's heart? A. 0.020 N B. 0.20 N C. 20 N D. 2000 N

REMEMBER THE SI UNITS FOR MASS IS KG and DISTANCE IS M 20 g x (1kg/10^3) = 0.02 F = ma find acceleration first! (delta v / delta t) 35-25 = 10 cm t = 0.10 (delta v / delta t) = 10/0.1 = 100 cm = 1 m F = ma = 0.02 x 1 = 0.02

According to Table 1, what is the concentration of the glucose in the blood from which the diluted sample was taken? A. 60 mg/dL B. 90 mg/dL C. 120 mg/dL D. 150 mg/dL

YESSS set up a proportion with the known value against the diluted blood sample, then solve for X we get 5mg/dL as the glucose concentration in the diluted sample but we want to know the total, so we take the dilution ratio 1/30 30 x 5 = 150!

Roughly to what height would a 5 kg stone need to be raised in order to have the same stored energy as the energy stored in the defibrillator's capacitor? A. 4 m B. 8 m C. 16 m D. 32 m Passage: 400 J at 5000v

U=mgh h = U/mg h = 400/(5)(10) = 8 m

Based on the passage, what is the primary type of interaction that RT makes with Compound 2? A. Covalent B. Hydrogen bonds C. Ionic D. Hydrophobic Passage: "The inhibitor binding pocket contains the side chains of Val106 and Phe227, which make the strongest interactions with compounds 1-3"

Val and Phe = hydrophobic!! FAMILY VW (D)

Limestone does NOT decompose when heated to 900 K because, at 900 K, ΔH is: A. positive and less than TΔS. B. positive and greater than TΔS. C. negative and less than TΔS. D. negative and greater than TΔS.

does not decompose = not spontaneous!! therefore delta S needs to be - and delta H is + B positive S means that it's going to be spontaneous therefore we want S to be negative

The ionic form of which metal atom is NOT likely to be found in the pocket of a catalytically active DNA polymerase? A. Zn B. Fe C. Mg D. Na

Zn2+ Fe2+ Mg2+ Na+ therefore the only one that makes sense is Na+ so D

Of the events listed, which occurs first during action potential generation? A. Voltage-gated sodium channels open at the axon hillock. B. Hyperpolarization stimulates the opening of ligand-gated potassium channels. C. Graded potentials propagate along the axon. D. Calcium influx stimulates vesicle fusion and release of neurotransmitter.

depolarization!! action potential needs voltage gated sodium channels to function

mixed inhibitor

do not bind to active site and will either bind to enzyme or enzyme-substrate complex

What atom remains after the β- decay described in the passage? A. Si B. Al C. S D. Cl

beta minus decay: neutron -> proton gaining a proton therefore go up 1 atomic number P -> S S!

In which of the following steps is the carbamate amide group cleaved? Passage: a carbamate is both an amide and ester

carbamate amide group: nitrogen adjacent to the O of an ester group C!

The electric field inside each of the conductors that forms the capacitor in the defibrillator is zero. Which of the following reasons best explains why this is true? A. All of the electrons in the conductor are bound to atoms, and thus there is no way for an external electric field to penetrate atoms with no net charge. B. Free electrons in the conductor arrange themselves on the surface so that the electric field they produce inside the conductor exactly cancels any external electric field. C. Free electrons in the conductor arrange themselves on the surface and throughout the interior so that the electric field they produce inside the conductor exactly cancels any external electric field. D. All electrons in the conductor, both free and bound, arrange themselves on the surface so that the electric field they produce inside the conductor exactly cancels any external electric field.

conductors that form the capacitor in the defibrillator is zero conductors contain: atom bound electrons & free electrons free electrons arrange themselves on the surface of conductors collective electric field produced inside the conductor cancels any external electric field. therefore the resulting electric field inside the conductor is zero

Why was it important that the cuvettes containing the glucose oxidase and the blood sample were identical in terms of optical properties? A. To enable the comparison of the absorption spectra B. To reduce the absorption in the glass walls C. To decrease the uncertainty in the wavelength D. To increase the absorption in the solutions Passage: "a blood sample with 1/30 dilution ratio was mixed in a transparent cuvette with an oxygen-acceptor solution containing glucose oxidase."

curvettes in spectroscopy they are measuring absorbance!! therefore we need to have a "reference" using the curvette A! to enable the comparison of the absorption spectra

lactone

cyclic ester

increase wavelength

decrease frequency decrease energy

What is the magnitude of the electric field in the electrical discharge produced in the excimer laser tube? A. 2.0 × 106 V/m B. 4.0 × 105 V/m C. 6.0 × 104 V/m D. 8.0 × 103 V/m

electric field E = F/q E = V/d ** if you're confused on what equation, look at the units and it'll help you. so V/m so it'll be volts/distance ** A

Define current

flow of charge per time

Which of the following reasons best explains why it is possible to separate a 1:1 mixture of 1-chlorobutane and 1-butanol by fractional distillation? A. Both 1-chlorobutane and 1-butanol are polar. B. Both 1-chlorobutane and 1-butanol are nonpolar. C. The boiling point of 1-chlorobutane is substantially higher than that of 1-butanol. D. The boiling point of 1-chlorobutane is substantially lower than that of 1-butanol.

fractional distillation: separates according to boiling point anything that has more hydrogen bonds will have a higher boiling point 1-chlorobutane vs 1-butanol 1-butanol will have a higher BP due to the OH group. D! The boiling point of 1-chlorobutane is substantially lower than 1 butanol

Which of the following atoms gains one electron most readily? A. Ar B. Br C. Co D. Na

gains electrons most readily = most electronegative!! do NOT include halogens, since their orbitals are already full, inert (TRAP ANSWER) B!

deposition

gas to solid (exothermic)

What is the concentration of the acute leukemia CC95 Combination value in micromolar (μM) units? A. 6 × 10-10 μM B. 6 × 10-7 μM C. 6 × 10- 4 μM D. 6 × 10-2 μM

given 0.6 nM, just convert it to microM

Two vectors of magnitudes |A| = 8 units and |B| = 5 units make an angle that can vary from 0° to 180°. The magnitude of the resultant vector A + B CANNOT have the value of: A. 2 units. B. 5 units. C. 8 units. D. 12 units.

if you add 8 + 5 = 13 (highest value) if you subtract 8-5 = 3 (lowest value) Therefore the value you cannot have is 2 units **easiest is to find the range of number that it can occur**