FL 5 AAMC MCAT Questions and Answers 2024/2025, Exams of Chemistry

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FL 5 AAMC MCAT Questions and Answers

What is the chemical structure of a component found in four of the five cofactors used by Na+- NQR? says it is composed of flavin structure is a nucleotide base structure B could be structure C also could be structure D is an amino acid down between B and C to help, look at the captioned note on the table. it says Fl represents flavin which is the redox active center in four of the five cofactors of Na+-NQR C has an uniquinone AND HERE IS IS MENTIONED THAT UNIQUINONE IS IS A SUBSTATE What is the ratio of cation to enzyme in the spectroelectrochemical experiments described in the passage? cation : enzyme passage says Na+NQR was diluted to a final concentration of 0.75 mM in 0.150 molar of the cation ions cation .15 M: The reaction between NADH and ubiquinone is exergonic, but the reaction, when catalyzed by Na+-NQR, does not generate much heat in vivo. What factor accounts for this difference? Conservation of energy, it is not created nor destroyed but merely changes forms A. Is not possible, Even if it was heat generation would be larger for a catalyzed rection. C. is impossible, reactants have to be close together to react The movement of a charged particle against its concentration gradient is energetically costly. Two open flasks I and II contain different volumes of the same liquid. Suppose that the pressure is measured at a point 10 cm below the surface of the liquid in each container. How will the pressures compare? pressure=pgh g= p= density (same liquid so same density) h= 10 cm both have same height so pressure will be the same-- if heights were different pressure would be different

Question Which of the following substances is polar? If there is a net dipole it is polar Question If all else is held constant, which of the following changes would NOT double the volume of a gas? pv=nrt What is the number of neutrons in the nucleus of the atom used to produce laser radiations? 86Kr+ laser 86= mass Kr has proton number as 36 86 - 36= the cation or anion charge with any element is indicative of the charge aka electron count What is the molecular formula of the heterocyclic aromatic compound pyrrole? passage says its a tetra pyrrole so there are 4 carbons The radiation of wavelength 605 nm CANNOT be used to produce the fluorescence radiations depicted in Figure 3 because: Maybe if you read the passage for once in your life and not get confident then maybe you wouldn't have to take the exam for a third time Not D because look at the passage not C because of E=hc/lambda (high wavelength low energy) Approximately how many moles of Kr+ are contained in the laser tube at 0°C and 1 atm? Have to recognize STP conditions of 0 C and 1 atm (22.4 L) Volume in PV=nrt is in L 1cm^3=1mL The CD spectroscopy signal that was used to generate the data in Figure 1 arises from the chirality of the: look for what is chiral B is not C is not D- most beta carbons are not chiral Samples from various time points of the proteolysis of TPMTwt were subjected to SDS-PAGE under reducing conditions. Which figure best depicts the expected appearance of the gel?

• For proteolysis, the protein is expected to be broken up over time
• Small fragments will travel faster in the SDS-PAGE A and B show that they are building up or oligermizing

C.

The protein unfolds and exposes W96 to the buffer. D. CHCl3 extracts W96 from the protein interior. Passage says: temperature which fully denatures carbonic anhydrase but leaves its primary structure intact primary structure= amino acids Peptide bonds are not broke What is the name of the ionic compound used to make Buffer B? A. Ammonium formate B. Ammonium carbonate C. Ammonium bicarbonate D. Ammonium acetate formate: hco carbonate: Hco3- bicarbonate: hco3- acetate: ch3cooh Which chromatographic technique would most likely separate a mixture of native carbonic anhydrase from carbonic anhydrase photochemically modified by CCl3CO2H? Passage says: Native carbonic anhydrase also has a net charge of - 2.9 at pH 8.0. The photochemical adds carboxylic acids which are negatively charged Pv=nrt Helps you look at the relationship between everything 4 mols of CO react to give you 2 mol of product n is halved that mean pressure is halved bc direct relationship 0.5* In which phase(s) will the MCS precursor be predominantly found after the extraction step? Passage MCS is a lipophillic precursor (it loves lipids) so it is not water soluble When the covalent attachment to alliinase is broken, PLP is still held rigidly in the active site by a salt bridge and a π-stacking interaction. These interactions are most likely provided by the side chains of which amino acids? Can eliminate B and D because they do not include pi stacking (tyrosine pi stacks) Now between Asp and Arg. Use passage info

Alliinase is a pyridoxal phosphate (PLP, vitamin B6) dependent enzyme. PLP is a planar molecule with a 6 - membered ring, a hydroxyl group, an aldehyde group, and a phosphate. PLP is covalently attached to alliinase by forming an aldimine with the side chain of the amino acid at position 251. So negative needs a positive to stabilize (phosphate in the group when deprotonated would be negative) As the pH of a solution of this amino acid is raised, which group deprotonates first? Between I and III I would be more acidic because the negative charged is stabilized through inductive effect of the neighboring electronegative chlorines In the case of III the negative charge would be unstable because of the close charge seaparation from the amino group units for capacitance farad If both the capacitor and the power supply in Figure 1 are adjustable, which of the following changes would result in an increase in the charge on the capacitor? Jack Westin Advanced Solution will be added here. A. Decreasing the area of the parallel plates B. Decreasing the separation between the parallel plates C. Removing the dielectric from the capacitor D. Decreasing the voltage of the power supply Q=CV and also C=AE0/D Adding a dielectric will increase the capacitance and therefore decrease the energy stored in a capacitor If the wavelength of a light beam were doubled, its frequency would be: c=lambdaf If the energy of a photon is doubled, which of the following properties of the photon will also double? e=hc/lambda e=hf An ester is prepared by the method of direct esterification using an esterase enzyme as a catalyst. Which of the following modifications will NOT appreciably increase the final yield of ester? B. increase on reactant will shift to products C. increase in reactants will shift to products D. removing product will cause product to freak out and get it

passage: identify a past event, physical and emotional stess respoonse parietal lobe- it intergrates sensory information and it would least likely to be used in this case prefrontal cortex- involved in executive functioning and decision making amygdala- emotional encoding The patient described in the passage is most likely using which defense mechanism? Passage: pt has low self esteem and says he feels inferior towards his successful partner, hates feeling tht wsy, stop ttending social events with partner bc elevates feelings of inferiority but also has love for him Projection= occurs when someone attributes unacceptale thoughts or behaviors within themself to another person rationalizatio-- logical explanation for unacceptable behavior rxn formation- minimizing uncomfy thoughts or emotions by overemphasizing their opposite. emotion displacement- involves shifting emotion from a less to more acceptable target The independent variable can usually be controlled independent variables have to be experimentally manipulated Which statement best explains the patient's behavior in terms of operant conditioning? C. A positive punisher decrease the frequency of the preceding behavior by introducing an aversive stimulus. pt's attendance of social events decreased as a result of his event attendance leading to the elevation of feelings of inferiority Weber's characteristics of an ideal bureaucracy suggest that most formal organizations will:

• Employment in a formal organization is based on technical qualifications
• Weber's conceptualization of ideal bureaucracy- formal organization requires specializtion in a limited number of tasks rather than completing a variety of tasks
• hierarchy makes decisions
• standarized rules Question A 34-year-old man has had a series of brief relationships with several romantic partners, but has never established a close, intimate relationship with a partner. According to Erikson's theory of psychosocial development, which outcome best describes this example? role confusion is in adolescents stagnation is a stage in erikson for middle adulthood Question Which statement best describes the sociological conceptualization of race and ethnicity?

• race and ethnicity change over time and location
• not based on physical characterisitcs because they encompass social and cultural categories Which construct best describes the process in which an immigrant group comes to express the cultural values and norms of a new country?
• Cultural transmission- transmission of values and practices from one generation to another
• Cultural relativism- understnading every culture is unique in someway
• cultural diffusion- mutual exchange of cultural values and practices among cultural groups in a society or among societiies Which conclusion demonstrates a fundamental attribution error when interpreting the results of the study? Fundamental attribution error refers to the tendency to attribute's people behavior to dispositional traits If participants in the study rated the administrator's attitude more inconsistently in the "Alone" condition than in the "With Others" condition, then: In statisitics, standard deviation increases when there is a greater variance in participants' responses (when the responses are inconsistent) standard deviation is a measure of how spread out the numbers are In the study, what is the most likely outcome if participants exhibited social facilitation? do better when people are watching Which construct is most relevant to the description in paragraph 2 about the comparison of two wines with different levels of sweetness? As more sugar is added, subtle changes in the sweetness of wine can be detected by both experts and novices. Weber's law- minimum change in intensity necessary for subject to sense that the stimulus has changed is a ration of the original stimulus intensity perceptual constancy- tendency to experience a stable perception even as a sensory input itself is changing absolute threshold- smallest amount of physical stimulation required to detect a sensory input half of the time it is present Which factor is most likely a potential confounding variable in the study described in the final paragraph? To examine whether visual information was more relevant than a flavor profile in eliciting an accurate description of the wine's flavor, researchers had 54 novices—students training to become sommeliers— perform two different wine comparison sessions. In each individual testing session, people tasted two different wines, one red and one white, and described the two wines. In the second session, one week

a larger society labeling theory- focuses on how deviant behaviors in the past have long term stigmatiizng impacts on individuals In subsequent research, the study is expanded to examine how high-SES African American adolescents adapt to predominantly white neighborhoods. Which concept would be LEAST applicable to this follow-up study? Social role conflict- conflicitng demans of two different social roles an individual carries demographic transition- model that changes in a country's population. population will eventually stop growign when the country transitions from high birth rates and high death ates to low birth rates and death rates The participants in Study 1 ignore information that suggests that negative events are more likely than they think. This is best characterized as an example of: cognitive dissonance- individual holds two attitudes and it stresses them group polarization- people have their own ideas (vs group think where everyone just conforms) representatuve heuristic- you think i am a doctor because i am wearing scrubs and that confirms the prototype of a doctor wearing scrubs The future research described at the end of the passage is LEAST likely to be designed with which type of method? Ethnography- make in person observations in a cultural setting for an extended period of time not experimental because this deals with cancer pts and caregivers which is experimental In a case study with an infant, Watson paired the presentation of a white rat with a loud noise. After several pairings, the infant was afraid of the white rat and also other stimuli that were white and furry, such as a white rabbit. The infant's fear response to the white rabbit is due to the process of: Spontaneous recovery- reappearance of an extinguished response after a period of nonexposure to the conditioned stimulus Question In operant conditioning, partial reinforcement, rather than continuous reinforcement, leads to a response that is: continuous reinforcement- fast rate of acquisition but quicker to extinction partial reinforcement- slower acquisition and slower extinction A woman's manufacturing job is unexpectedly outsourced to a factory in Country A. She responds with hostility and anger towards all people from Country A and accuses them of taking her job. Which concept best describes her response? Xenophobia- fear and suspicion towards cultures perceived to be foreign ethnocentrism- values and practices of other cultures is evaluated by someone's own cultural lenses and is considered as inferior

The categorization aspect of the cognitive functioning assessment involves which type of memory? Not short term because sort term can only hold it in for a couple of seconds semantic memory- facts and knowledge episodic memory- long term memory for personally experienced events Based on the passage, participation in which study is most likely to be associated with a decrease in hippocampal volume in rats? Studies on animals have shown that chronic increases in stress-related hormones are associated with reduced dendritic spines, decreased long-term potentiation, and reduced neurogenesis in the hippocampus. Studies on humans show that people who have experienced posttraumatic stress disorder have reduced hippocampal volume. avoidance learning- occurs when an individual eresponse to prevent the presentations of an anversive stimulus and and learned helpeless is a behavioral and physiologucal state that occurs as a result of exposure to uncontrollable aversive consequences avoidance- before the stress even happens you avoid it The morphological changes associated with elevated stress or exercise are examples of: Maturation- expected development associated with the gradual unfolding of one's genetic blueprint neural transmission- communication between neurons Which process most likely accounts for the effect of the peer group's response, described in paragraph 4, on a teenager's drug experimentation? Normative- individuals acting in ways that comply with the norms of their social groups information social influence- individuals conform to others' behavior because they are in an ambigious situation for which they do not have a script Participants' scores on the antagonism scale are most likely associated with scores on which personality trait? "To assess personality, the researchers developed a brief inventory (the HP5) based on the Five-Factor Model of personality." big 5 OCEAN conscientiousness= related to organization, punctulaity, and dependability sensation- degree to which indiviudals seek novelty and high stimulating activities openness- curiosity, imagination, and unconventional attitudes Participants' responses to the self-statements on the inventory described in the passage could be affected by each of the following confounds EXCEPT:

An increase in which of the following physiological variables is most likely to cause an increase in the amount of EPO released by the kidneys in a healthy human adult? increase in aerobic exercise causes an increase in oxygen demand Expression of the rHuEPO gene in E. coli bacteria produced an EPO protein that did not increase erythrocyte production when injected into humans. The most likely reason for this observation is that:

• post translation modifications are usually for eukaryotes
• prokarytes and eukaryotes read the same way post translational modifications take place in the ER Certain types of kidney tumors continuously produce and release EPO. Such tumors most likely have which of the following effects, if any, on erythrocyte production? liver doesn't product erythroycytes According to the data presented in the passage, 5-HTR4 is a: Passage says that 5-HTR4 is a transmembrane protein that binds to 5-HT and 5-ht increases camp levels In an experiment in which IBU alone was administered to normal mice in order to determine whether long-term treatment with the analgesic can cause behavioral symptoms of depression, what would be the appropriate control group? Usually in experiments you compare the the thing with the thing and then another without the thing Which comparison best determines whether IFNγ is necessary for antidepressant-induced increases in the expression of p11? In order to study antidepressant-induced increases in p11 expression, both test groups must be given an antidepressant or SSRI. To study the additional effect of IFNgamma one test group should be non- affected (wild type) and other should lack ifn gamma Which type of reaction has a Keq > 1 and is kinetically fast? Yeah there are more products than reactants small k value indicates more reactants than products Which outcome most likely results from exposure of Ogg1-/- mice to TNFα Passage says that OGGI is shown to be a key part in recognizing DNA damage base excision repair due to ROS damage. TNFalpha is stated to result in greater ROS and more DNA damage. Increased DNA damage wit reduced repair mechanisms is more likely to increase cancer incidience. The resting potential of a neuron is primarily a result of the: Ca2+ pumps actively transport Ca2+ out of the neuron. Intracellular Ca2_ primalriy cntrols neurotransmitter release and not the resting potential of the neuron/

In an enzyme-catalyzed reaction where enzyme concentration is held constant and substrate concentration is relatively low, which kinetic parameter will increase with the addition of more substrate? More substrate= Km, kcat, and vmax are not affected The more substate initially the more enzymatic reactions occur Question Consider an experiment that consists of two ionic solutions separated by a membrane that contains a ligand-gated potassium channel. The lack of current generation in response to addition of ligand is explained by: If there are equal concentrations in the two ionic solutions it should follow then there is not net movement of ions across the channel and no current generation no current can also mean that the concentration on both sides is the same A particular diploid organism is heterozygous in each of 3 unlinked genes. Considering only these 3 genes, how many different types of gametes can this organism produce? Heterozygous for 3 indepedent/unlinked genes so their genotype is Aa, Bb, Cc each gamete they produce can inherit one allele of each gene 2 possibilits for gene 1, 2 for gene 2, 2 for gene 3 2 2 2 Each gamete will receive one copy of each chromosome and one allele for every gene each gamete can inherit one allele of each gene Lactase can be classified as which type of enzyme? Converts lactose into glucose and galactose Passage says that lactase breaks down lactose to glucose and galactose glycosidic linkages in disaccharides are cleaved by a hydrolysis reaction A they are not isomers, D, no C. nothing is being transfered so cannot be a transferase Which cells express lactase? C. Parietal cells secrete Hcl so would not make sense. B. Colon helps concentrate feves so would not make sense. D.Hepatocytes are liver cells and do not produce enzymes Enterocytes are intestinal cells that produce enzymes that digest disaccharides Based on the information in the passage, the mutation that causes the LP phenotype is most likely located in: LP phenotype: resultsin lactase being produced but the difference is the amount and timing of expression, more likely to be the function of enhancers