AAMC FL 1 Exam Questions and Answers 2024

AAMC FL 1 Exam Questions and Answers 2024 If Reaction 2 (Figure 4) is repeated with HCl and the compound shown below, which of the following compounds is NOT a direct product (without rearrangement)? -Answer-Compound A requires a hydride shift to form- therefore not a direct product. NOT an SN2 reaction because of tertiary alcohol- it is SN1 What is the energy of the photons emitted by the LED at a frequency of 610 THz? (Note: h = 6.6 × 10-34 J·s) -Answer-The photon energy is the energy carried by a single proton. The equation used for calculating photon energy is: E = hc / λ where h = Planck constant c = speed of light and λ = wavelength of photon frequency = f = c / λ replace c /λ with f in the equation of photon energy E = hf frequency = 610 thz = 6.1 x 10¹⁴hz h = 6.26 x 10⁻³⁴ js E = 6.26 x 10⁻³⁴ x 6.1 x 10¹⁴ E = 3.8 x 10⁻¹⁹ j Which amino acid residues were incorporated into Compound 1 to promote the adhesion of cells on the scaffold surfaces? -Answer-The passage describes the five regions of the compound, identification of the amino acids within the five regions provides the answer. Compound 1 was designed to exhibit pH-dependent self-assembly. What feature(s) of the molecule is(are) responsible for the pH dependence of aggregation (Equation 1)? -Answer-Side chains whose net charge responds to pH The answer is because the molecule contains mainly acidic side chains that were deprotonated and negatively charged at high pH. This inhibited aggregation due to electrostatic principles. At low pH these groups are neutral and allow aggregation. Why is the velocity of blood flow slower in capillaries than in arteries? -Answer-Capillaries in the body pump blood at a slower velocity than arteries, because even though arteries are larger individually, the total area of capillaries throughout the body is greater. On an individual basis though, vasoconstrictors like epinephrine cause arteries (the smaller ones that are composed of more smooth muscle) to narrow which increases blood flow. Darcy's Law (Continuity Equation) where Q=Av. If A increases, v decreases since blood flow volume is constant The source of the phosphate groups that are added to rhodopsin is: -Answer-Kinases are enzymes that posphorylate molecules, not the actual source. ATP (along with other NTPs) are typically your source of phosphate groups Which reaction is catalyzed by LipA? -Answer-LipA is a lipase, which means it must hydrolyze fatty acids Compared to the wild-type LipA, what is the change in net charge in variant XI at pH 7? - Answer-So you look at the table of amino acid substitutions for variant XI R33G, K112D, M134D, Y139C, I157M The first letter is the WT, the last is the substitution. At pH=7 you need to figure out the change in charge for each aa. For example, R= arginine has a pkA of 12.5, pH < pkA it will be protonated so the charge is +1; G = Glycine is neutral so you are substituting the +1 charge with a charge of 0. If you do this for all of them you'll get original: +2 substitution: -2 which is a -4 difference. By what factor is the proton concentration increased in the experiments shown in Figure 1B from those shown in Figure 1A? -Answer-The answer to this question is D because the pH scale is logarithmic (pH = −log([H+]). A difference of 3 pH units corresponds to a 103 = 1000-fold difference in proton concentrations. It is a Scientific Reasoning and Problem Solving question because you are asked to determine and then use a formula to solve a scientific problem. Addition of laforin to the reaction mixtures used to generate the data in Figure 2 will result in - Answer-The SDS-PAGE on the left has 14C tagged glucose, and so is also a control to see how much glucose is incorporated into the glycogen. Laforin should not affect this, so we rule out the answers involving 14C. The SDS-PAGE on the right has 32P tags, which marks phosphorylation activity of our glycogen. Laforin, which is a phosphatase, should remove radiotagged phosphate from our glycogen, so the band should be less intense, as compared to a reaction mixture without laforin, which would have radiotagged phosp