AAMC PRACTICE EXAM #5 C/P Question with complete solution 2023

AAMC PRACTICE EXAM #5 C/P Question with complete solution 2023Compound 1 is used to treat HIV infection based on its ability to act as: B. an antagonist - P2 states that Compound 1 is a potent HIV protease inhibitor - HIV protease is an enzyme that is targeted to treat HIV infection - an antagonist impedes on the normal function of a system CORRECT How many stereoisomers of Compound 1 exist? C. 32 There are 5 chiral carbons indicated in the figure 2^n rule n= # chiral carbons CORRECT Why do kidney stones form in some individuals treated with Compound 1? B. [Ca2+][C2O42-] > Ksp Ksp is the solubility product constant - the formation of kidney stones are composed of calcium oxalate CaC2O4 CORRECT The peptide bond between which two amino acid residues is cleaved by HIV protease? D. Phe and Proline Phenylalanine Proline Proline has N ring Ph - Phenyl group CORRECT Which image best illustrates the electric field lines between the inside of an axon and the surrounding extracellular solution? B. Electric field pointing from extracellular fluid to axon interior - An axon is negatively charged because there the concentration of Na+ is higher outside of the cell - Extracellular environment is more positive than inside of axon - Electric fields point from positive charges towards the negative point, electric field lines are trajectory or unit positive charge in a given electric field INCORRECT One function of the myelin sheath is to: A. insulate the axon from the surroundings - the myelin sheath is an insulating layer that forms around nerves - as conductivity decreases insulation increases with myelin sheath as shown in Table 1 INCORRECT the myelin sheath allows _________ __________ to transmit quickly and efficiently along nerve cells electrical impulses function of myelin sheath increases speed of electrical impulses in neurons Channel X transmits only the smallest substances dissolved in the extracellular fluid through the axon membrane. Which substance does Channel X transmit? B. Sodium ions - smallest ion atomic number 11 CORRECT What is the closest distance the electrodes used in an NCV test can be placed on a nerve in order to measure the voltage change as a response to the stimulus? B. 0.1 m - one action potential travels 1 msec - pulse travels at 100 m/s (100 m/s)(.001 s) = .1 m CORRECT