AAMC FL 1 exam Questions with 100% correct answers 2024, Exams of Chemistry

Download AAMC FL 1 exam Questions with 100% correct answers 2024 and more Exams Chemistry in PDF only on Docsity! AAMC FL 1 exam Questions with 100% correct answers 2024 In the chromatography of the reaction mixture, water absorbed on cellulose functioned as the stationary phase. What was the principal factor determining the migration of individual components in the sample? A.Hydrogen bonding B.Solute concentration C.Stationary phase concentration D.Thickness of paper - correct answer B and D are dumb options. Knock them out. hydrogen bonding to the stationary phase will determine the relative rate of migration of the various components in the sample. When thinking migration, think bonding. If it bonds super well, it isn't going to move very far. What assumption is being made if scientists conclude that aspartic acid was formed by the prebiological synthesis in the passage? A.Aspartic acid is unstable at temperatures below 150°C. B.All of the malic acid underwent the dehydration reaction to form fumaric/maleic acid. C.Compound A and cyanide were available on primitive Earth. D.The reaction between ammonia and fumaric acid was catalyzed by the presence of water. - correct answer POE: The steric hinderance is not at the oxygen. It's talking about all the other crap. What's important is the Halide being able to attack the carbocation intermediate, which is made more difficult by hinderance from the extra alkyl groups since it's further down the chain The oxygen isn't sterically hindered. Its actually pretty available to be protonated. The carbon however is surrounded by other carbons and hydrogens which increases steric hindrance at that site. Which is actually the only thing that matters since the nucleophile will be attacking that carbon and not the oxygen that presumably already left the molecule as H20. D is correct. Hydride shifts - correct answer are not DIRECT products. direct products= products without rearrangement. If a solution containing the compounds shown in Figure 4, is injected into a gas- liquid chromatograph, the first peak observed in the gc trace is attributable to which compound? A.2-Methyl-2- butanol B.2- Methyl-2-butene C.2-Chloro-2-methylbutane D.2-Bromo-2-methylbutane - correct answer Gas chromatography will elute the LIGHTEST molecular weight FIRST. B is the lightest compound Chirality - correct answer if lowest priority is on a wedge, flip the stereochemistry. if on dash, you gucci In determining which reactant loses the -OH group, which of the following isotopic substitutions would be most useful? A.Replace the acidic H of acetic acid with D. B.Replace the alcoholic H of ethanol with D. C.Replace the carbonyl oxygen of acetic acid with O-18. D.Replace the hydroxyl oxygen of ethanol with O-18. - correct answer D. this would be the oxygen that is added to the product A person, whose eye has a lens-to-retina distance of 2.0 cm, can only clearly see objects that are closer than 1.0 m away. What is the strength S of the person's eye lens? (Note: Use the thin lens formula 1/O+1/I=S A.-50 D B.-10 D C.51 D D.55 D - correct answer ***CONVERT EVERYTHING TO METERS FOR LENS MAKER 1/f = 1/o + 1/i S = 1/1 + 1/0.02 1+ (1e0/2e-2) 1+.5e2 1 + 50 = 51 D. Which statement correctly describes how enzymes affect chemical reactions? Stabilization of: A.the substrate changes the free energy of the reaction. B.the transition state changes the free energy of the reaction. C.the substrate changes the activation energy of the reaction. D.the transition state changes the activation energy of the reaction. - correct answer D!!!! Yes queen. stabilization of the transition state, not the substrate, provides binding energy that is used to lower the activation energy. Which of the following will decrease the percentage ionization of 1.0 M acetic acid, CH3CO2H(aq)? A.Chlorinating the CH3 group Passage: PMPA = Pd + (Ps - Pd)/3 Pp = Ps - Pd - correct answer c. 3PMPA= Pd+ (Ps- Pd) *you see from the first equation that Pd is directly related to 3PMPA put three in front of it. *also, C is the only answer choice with a -pd answer and a 3pmpa What percentage of standard atmospheric pressure is the pulse pressure of a healthy adult? A.10% B.6% C.2% D.1% Passage: Ps = 120 mmHg and Pd = 75 mm Hg pulse pressure Pp is defined as Pp = Ps - Pd - correct answer SO. Let's look at this. Pulse pressure is the difference between these two. (120-75)= 45 Standard atmospheric pressure is 760 mm hg. round--->45/760 = 9/152 ~ 9/150 = 3/50 = 6/100 = 6% What fraction of a 15O sample decays in 10 min? A.1/8 B.9/16 C.3/4 D.31/3 2 Passage: 15O (with a half-life T1/2 = 2 min) - correct answer There are 5 half-lives in 10 minutes. (1/2)^5=1/32 Only 1/32 will remain of the sample. So, 31/32 of the sample decayed. What is the work generated by a healthy adult who circulates 9 L of blood through the brachial artery in 10 min? A.2 kJ B.12 kJ C.20 kJ D.120 kJ - correct answer ***want minutes in seconds 9L= 900ml 900ml corresponds to 200w Power= work/time 200w= work/600 seconds 200x600=120,000 120 kj Compared to micellular Compound 1, Compound 2 is structurally more rigid as a result of what type of interaction? A.Intermolecular hydrogen bonding B.Intermolecular covalent bonding C.Intramolecular hydrogen bonding D.Intramolecular covalent bonding Passage: Molecules of Compound 1 spontaneously self-assemble into cylindrical micelles in water at pH 4 but freely redissolve at pH 8. Oxidation of self-assembled, micellular Compound 1 with iodine resulted in a solid material (Compound 2) which is stable in alkaline solutions. - correct answer B. Since the passage indicates that multiple compound ones are coming together to form compound 2, this question wants to to pick intermolecular forces. (cross out C and D) Oxidation= covalent bonds Think oxidation of cysteine to make disulfide bonds. intermolecular forces - correct answer forces between molecules intramolecular forces - correct answer forces within molecules. Which amino acid residues were incorporated into Compound 1 to promote the adhesion of cells on the scaffold surfaces? A.Arg and Gly B.Cys and Gly C.Cys and Asp D.Asp and Arg - correct answer D. arginine and aspartic acid are actually located in the molecule. adhesion to cells would need an attraction and difference in charge Which amino acid was incorporated into Compound 1 as a future site of covalent attachment to HA prior to mineralization? A.S er B.Al a A.increase sensitivity to low light. B.enable the detection of different colors. C.ensure fast recovery of 11-cis-retinal after exposure. D.increase refractive index of the eye lens. Passage: Additional opsin based receptors are expressed in specialized cone cells and have maximum absorptions at 420 nm, 530 nm, and 560 nm when reconstituted with 11-cis-retinal. - correct answer CONE CELLS! POE A- this is talking about rods B- YES, cones detect color C- no dumb answer choice D- no dumb answer choice The environment of the retinal binding site is most likely: A.hydrophilic. B.positively charged. C.negatively charged. D.hydrophobic. - correct answer D. the retinal molecule has like all hydrophobic regions. The source of the phosphate groups that are added to rhodopsin is: A.arrestin. B.rhodopsin kinase. C.ATP. D.all-trans-retinol. "Wild-type or variant rhodopsin was reconstituted with 11-cis-retinal and phosphorylated by rhodopsin kinase in the presence of ATP before examining arrestin binding." - correct answer C. Literally says it in the passage! What are the hybridization states of the carbon atoms involved in the conversion of trans to cis retinal? A.sp B.sp 2 C.sp 3 D.sp3d - correct answer B. double bond orientation is what determines trans vs cis Which reaction is catalyzed by LipA? A.ATP hydrolysis B.Peptide bond cleavage C.Hydrolysis of triacylglycerides D.Transfer of carboxyl groups - correct answer LipA is said that it is lipase Lipase= hydrolyzes fatty acids! Triglyceride= fatty acid Compared to the wild-type LipA, what is the change in net charge in variant XI at pH 7? A. +4 B. +3 C. −3 A.Xylose B.Fructose C.Ribose D.Arabinose - correct answer UDP > uracil C) ribose Addition of laforin to the reaction mixtures used to generate the data in Figure 2 will result in: A.a decrease in the intensity of the band representing WT without glucosidase when visualized with 14C decay. B.an increase in the intensity of the band representing WT without glucosidase when visualized with 14C decay. C.a decrease in the intensity of the band representing WT without glucosidase when visualized with 32P decay. D.an increase in the intensity of the band representing WT without glucosidase when visualized with 32P decay. Passage: LBs contain a much larger amount of covalently-linked phosphate compared to normal glycogen. The abundance of phosphate has been linked to a mutation in the gene for laforin, a phosphatase specific to carbohydrates. - correct answer ***ALL ABOUT PHOSPHATASE (bye A and B) Phosphatases REMOVE phosphates. C. The radioactive decay described in the passage results in the formation of which two atoms? A.N and S B.B and Si C.B and S D.N and Si Beta decay is talked about in the passage. passage: SDS-PAGE analysis from muscle extracts visualized with either 14C or 32P - correct answer The answer to this question is A because the type of radioactive decay is b-1 so a neutron is converted into a proton Carbon becomes nitrogen Phosphorus becomes Sulfur Alpha decay - correct answer Alpha particle is emitted. AKA a helium particle. 2 proton, 2 neutrons. 4He2. What happens? -4 from mass number -2 from atomic number ***only happens to atoms with big ass nuclei -easily blocked Beta decay - correct answer Changing nucleus by 1 Ejection of beta particle (aka an electron) Atomic number goes UP by one! D.3/2 - correct answer ratio of the image height to the object height is equal to the ratio of the lens- image distance to the object-lens distance. 3F ´ 1F/(3F - 1F) = (3/2)F, where F is the focal length. The ratio sought is then equal to (3/2)F/(3F) = 1/2. Gamma decay occurs when a nucleus emits: A.a photon. B.a proton. C.a neutron. D.an electron. - correct answer A. gamma decay means the emission of photons by the nucleus. When a 0.1 M H2SO4 solution is added to pulverized blackboard chalk, the following reaction takes place. CaCO3(s) + H2SO4(aq) CP-9-1 ---> CaSO4(s) + CO2(g) + H2O(l) At 25°C, the reaction is spontaneous and has: A.negative ΔG° and positive ΔS°. B.negative ΔG° and negative ΔS°. C.positive ΔG° and negative ΔS°. D.positive ΔG° and positive ΔS°. - correct answer SO we KNOW that entropy is INCREASING because there are 3 objects on the product side compared to 2 on the reactant side. This will be a positive delta S. (bye b and c) More disorder= more spontaneous= negative delta g Which of the following is the overall reaction for the decomposition of H2O2 that is shown in reactions 3 and 4? A.2H2O2(aq) + IO−(aq) → 2H2O(l) + I−(aq) + O2(g) B.2H2O2(aq) + 2I−(aq) → 2H2O(l) + I2(g) + O2(g) C.H2O2(aq) → H2O(l) + O2(g) D.2H2O2(aq) → 2H2O(l) + O2(g) - correct answer ** for these cross out what you see twice! You got it Which of the following diagrams does NOT illustrate a function of an automobile catalytic converter? Passage: the catalyst aids in the conversions of carbon monoxide to carbon dioxide, hydrocarbons to carbon dioxide and water, and nitric oxide to nitrogen gas. Unfortunately, catalytic converters also can catalyze the oxidation of SO2 to SO3 - correct answer Choose the one that isn't one of these Which of the following most likely will occur if a homogeneous catalyst CANNOT be separated from the products at the end of a reaction? A.The catalyst will become heterogeneous. B.The products will be contaminated. C.The reaction will not occur. D.The reaction rate will speed up. - correct answer Inability to separate will lead to contamination :) How will the rate of a catalyzed reaction be affected if the solid catalyst is finely ground before it is added to the reaction mixture? A.The rate will be faster because a greater mass of catalyst will be present. B.The rate will be faster because a greater surface area of catalyst will be exposed. C.The rate will be slower because the fine catalyst particles will interfere with product formation. D.The rate will remain the same because the mass of catalyst will be the same. - correct answer B. More surface area= faster A student can most effectively increase the current passing through the circuit in Figure 2 by doing which of the following? A.Using electrical wire with a smaller diameter B.Increasing the temperature of the electrical wire C. Decreasing the concentrations of Xn+(aq) and Ym+(aq) D.Replacing the lightbulb with one that has a resistance of 0.2 Ω - correct answer V=IR Increasing current---> decrease resistance When a strip of Zn is placed in a beaker containing 0.1 M HCl, H2(g) evolves. If a strip of Al is placed in a beaker containing 0.1 M HCl, does H2(g) evolve? A.Yes; Al is reduced and H+(aq) is oxidized. B.Yes; Al is oxidized and H+(aq) is reduced. C.No; Al is reduced and Cl-(aq) is oxidized D.No; Al is oxidized and H2O(l) is produced. - correct answer B. Since a new solid forms when Al(s) is mixed with Zn2+(aq), it is reasonable to assume that Al(s) is more susceptible to oxidation than Zn(s). Assume that a circuit similar to that in Figure 2 is set up in which X = Al, Xn+ = Al3+, Y = Cu, and Ym+ = Cu2+. Which of the following reactions will occur? A.2Al3+(aq) + 3Cu(s) → 2Al(s) + 3Cu2+(aq)