AAMC FL 1
A circuit similar to that in Figure 2 is set up in which X = Pb, Xn+ = Pb2+, Y = Cu, and Ym+ = Cu2+. Will an oxidation-reduction reaction occur spontaneously? A.No; E°cell = -0.212. B.No; E°cell = +0.212. C.Yes; E°cell = -0.466. D.Yes; E°cell = +0.466.
D- A spontaneous reaction occurs when E° is greater than zero, and this occurs if the oxidation of Pb(s) is combined with the reduction of Cu2+(aq), resulting in a net E° of +0.466 V.
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
has to be covalent bonding because oxidation of cpd 1 led to solid cpd 2 which can only happen through disulfide bonds which occur between two different cpds so B- Only Compound 2 has disulfide bridges, which is a type of intermolecular covalent bonding. A and C- can't be hydrogen bonding because both have that
In the above figure, an object O is at a distance of three focal lengths from the center of a convex lens. What is the ratio of the height of the image to the height of the object? A.1/3 B.1/2 C.2/3 D.3/2
B 1/f = 1/o + 1/i 1/f = 1/3f + 1/i 1/f -1/3f = 1/i 3/3 x 1/f - 1/3f = 1/i 3-1/3f = 1/i 2/3f = 1/i 3f/2 = i i/o ratio of height 3f/2/3 ===> 1/2
Each of the following equations shows the dissociation of an acid in water. Which of the reactions occurs to the LEAST extent? A.HCl + H2O → H3O+ + Cl− B.HPO42− + H2O → H3O+ + PO43− C.H2SO4 + H2O → H3O+ + HSO4− D.H3PO4 + H2O → H3O+ + H2PO4−
B HPO42- has a high negative charge and so dissociation of it will occur to the least extent. A and B- strong acids D- weak acid which will dissociate partially more than anionic phosphoric acid
Gamma decay occurs when a nucleus emits: A.a photon. B.a proton. C.a neutron. D.an electron.
A- By definition, gamma decay means the emission of photons by the nucleus.
Based on the findings in the study, which conclusion about ADHD is most likely? A.Immediate performance feedback reduces impulsive responding in children with ADHD. B.Exposure to a gaming element increases impulsive responding in children with ADHD. C.Gaming elements on working memory tasks place high demands on divided attention and inhibit focus. D.Low levels of intrinsic motivation in children with ADHD are minimally enhanced with external reinforcers
A- Children in the gaming condition received immediate feedback after making each of their responses and shows less error
Which amino acid, in addition to tryptophan, is most likely to be transported by AT1? A.Phenylalanine B.Lysine C.Arginine D.Glutamate
A- AT1 is a neutral amino acid transporter. Tryptophan is like Phenylalanine is a neutral and aromatic amino acid.
The initial filtration step in the glomerulus of the mammalian kidney occurs primarily by: A.passive flow due to a pressure difference. B.passive flow resulting from a countercurrent exchange system. C.active transport of water, followed by movement of electrolytes along a resulting concentration gradient. D.active transport of electrolytes, followed by passive flow of water along the resulting osmolarity gradient.
A- There are three pressures that work together to regulate filtration in the glomerulus: glomerular capillary pressure capsular hydrostatic pressure blood colloid osmotic pressure. The glomerular capillary pressure will force filtrate from a capillary into Bowman's capsule; the other two forces promote movement of the filtrate in the opposite direction Just want to clarify one point for other viewers. Thick ascending loop of henle DOES actively (yes, ATP) transport Na+,Cl- , and K+ (reabsorbing back into the blood). But, this occurs after passive transport in the "thin" segment. This makes (D) wrong, which states that active transport occurs first. (C) is wrong because water does not require ATP to get transported. Key word in this Q I think is the glomerulus. This is where the initial filtration occurs, driven by the blood pressure (hydrostatic pressure). additional fun facts regarding the countercurrent exchange that occurs in the loop of henle: Descending loop of henle: permeable to water. IMpermeable to Na+. Hence, only water gets out (=reabsorbed back into the blood). Ascending loop of henle: IMpermeable to water, but permeable to solutes. Hence, this is where most salts get reabsorbed.
A man with a CRC mutation that results in the synthesis of HSP110ΔE9 and a woman that does not carry this mutation in any of her tissues have a child. What is the percent chance that the child will inherit the CRC mutation? A.0% B.25% C.50% D.100%
A- 0% Based on the passage, HSP110ΔE9 is only expressed in somatic cells, not germline. Thus, it cannot be inherited
Epilepsy may result in motor seizures due to massive synchronous firing of neurons in a small area of the cerebral cortex (the epileptic focus). Excitation spreads from the focus, involving an increasingly larger area of the cortex. A drug for the treatment of epilepsy would be most effective if it caused which of the following changes in the epileptic focus? A.An increase in the neuron-firing threshold B.An increase in extracellular Na+ concentration C.A decrease in axon-membrane permeability to negative ions D.A decrease in the length of the depolarization stage
A- An increase in the threshold would make it more challenging for a neuron to fire an action potential. This will reduce the frequency of downstream neuron depolarizations, resulting in relief of the symptoms. because increasing the threshold will reduce the firing as action potential is all or nothing phenomenon
Research findings indicate higher levels of patient trust and physician attention in race-concordant physician-patient relationships because: A.both the physician and patient belong to the same in-group. B.the physician and patient share similar levels of status. C.of racial hostility present in race-discordant relationships. D.of the lack of role strain experienced by the physician.
A- Members of in-groups tend to share common backgrounds and similar social group identities, which generally result in high levels of trust among in-group members. Racial/ethnic identity can be an important characteristic of an in-group, resting in a shared culture, language, or community. Thus, the higher levels of patient trust and physician attention in race-concordant physician-patient relationships can be explained by in-group affinity. can't share similar status because it can vary
Based on the information in the passage, a mature AT1 mRNA is most likely to contain a sequence coding for which genetic factor(s)? A.Signal sequence B.Introns C.Promoter D.Nuclear localization signal
A- Normally, the mature RNA sequence for a protein that is secreted or that will locate to the cell membrane will contain the signal sequence. This portion of the mRNA is located in the 5′ region and will signal to the ribosome that translation needs to be continued in the rough endoplasmic reticulum. introns and promoter are not present in mature mRNA nuclear localization signal is a sequence that tags protein for it to be transported into nucleus, since protein transporter is located on the cell membrane, this can't be true
Which amino acid was incorporated into Compound 1 as a future site of covalent attachment to HA prior to mineralization? A.Ser B.Ala C.Tyr D.Thr
A- Ser is the residue that was phosphorylated at its primary alcohol side chain for future attachment of nanocrystals of HA
When a 0.1 M H2SO4 solution is added to pulverized blackboard chalk, the following reaction takes place. CaCO3(s) + H2SO4(aq) 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°.
A- Spontaneous reactions must have a negative ΔG°, and reactions that create gaseous products from solids and liquids must have a positive ΔS°.
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
A- The β− radioactive decay of 14C occurs according to the reaction 14C →14N + e− + antineutrino, and that of 32P according to 32P → 32S + e− + antineutrino, so the resulting atoms are N and S.
In which direction does the Na+K+ ATPase transport ions across the cell membrane upon ATP hydrolysis? A.Na+ is transported out of the cell; K+ is transported into the cell. B.Na+ is transported into the cell; K+ is transported out of the cell. C.Both Na+ and K+ are transported into the cell. D.Both Na+ and K+ are transported out of the cell.
A- Upon ATP hydrolysis, three Na+ are transported outside the cell and two K+ are transported inside the cell against their concentration gradient.
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)?
A- can't be formed without rearrangment B- direct deprotonation of tertiary carbocation to form alkene C and D- enantiomers are direct formation
Which type of bond is formed by glycogen synthase upon release of UDP? A.α-1,4-Glycosidic bond B.α-1,6-Glycosidic bond C.β-1,4-Glycosidic bond D.β-1,6-Glycosidic bond
A- glycogen synthase forms .α-1,4-Glycosidic bond and glycogen branching enzyme forms α-1,6-Glycosidic bond
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
A- hydrogen bonding to the stationary phase will determine the migration of individual components in the sample. nonpolar molecules will not be attracted to water and travel further
Which measurement unit CANNOT be used to express power? A.kg•m2 •s2 B.J•s-1 C.ft•lb •s-1 D.W
A- this is just joules P = J/s also C can be converted to horsepower so it works
Upon activation, p65 and cRel control the level of IL-6 mRNA by: A.binding RNA. B.binding DNA. C.replicating RNA. D.replicating DNA.
B these proteins are transcription factors. which control the rate of genetic info from DNA. this happens by binding to the promoter region p65 and cRel are transcription factors and regulate the expression of other genes by binding to the promoter or the enhancer of the gene located on the DNA.
When the current in the micro-robot's circuit increases and the resistance of the circuit remains constant, the voltage of the circuit: A.decreases. B.increases. C.is constant. D.is zero.
B- Ohms's law V = IR I increases, V increases (direct r/s)
What percentage of standard atmospheric pressure is the pulse pressure of a healthy adult? A.10% B.6% C.2% D.1%
B- pulse pressure = Ps - Pd Ps= 120 mmHg Pd = 75 mmHg Pp = 120 - 75 = 45 mmHg we are going to divide it by atmospheric pressure which is 760 mmHg (outside knowledge) 45/760 = 6%
According to the passage, what is most likely correct about the genes that are expressed as a result of the constant activation of the NF-κB pathway? A.They cause disruption of the mitochondria. B.They contain a p65/cRel binding site in their promoter region. C.They have accumulated mutations that alter function. D.They bind to STN in the cytoplasm.
B- transcription factors contain binding promotor region can't be A because disruption of mitochondria leads to apoptosis and the passage mentioned supression of apoptosis; also it assumes a lot therefore it can't be true
The half-life of urea is the time it takes for its concentration to fall by one-half. The graph illustrates the clearance of urea from an initial plasma concentration of 200 ng/mL. If it takes five half-lives for urea to be considered eliminated from the body, how long did it take to eliminate the urea? A.1.5 h B.2.5 h C.3.5 h D.4.0 h
B- Based on the graph, it takes 0.5 h for urea concentration to be reduced by half, thus for 5 half-lives, 2.5 hours are required
The production of a variety of opsins functions to: 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.
B- Because the wavelengths of maximum light absorption are significantly different for the specialized opsins in the cone cells, these opsins enable the detection of different colors of light. A, C, D- no such info in the passage
Pellagra also results from a deficiency of nicotinamide, which is synthesized from tryptophan. Nicotinamide nucleotides are neither oxidized nor reduced during which step of cellular respiration? A.Glycolysis B.Chemiosmosis C.Citric acid cycle D.Electron transport chain
B- Chemiosmosis is the only step of cellular respiration where NAD+ is neither reduced to form NADH, nor is NADH oxidized to form NAD+ glycolysis NAD+ is reduced to form NADH TCA NAD+ is reduced to form NADH ETC NADH is oxidized to form NAD+
The equilibrium BaCrO4(s) Ba2+(aq) + CrO42-(aq) exists in a saturated aqueous solution of BaCrO4. Dissolution of Na2CrO4 in a saturated aqueous BaCrO4 solution would: A.have no effect on the position of this equilibrium. B.shift this equilibrium left. C.shift this equilibrium right. D.shift this equilibrium first right and then left.
B- Dissolution of Na2CrO4 would introduce the common ion, CrO42-, which would reduce the solubility of BaCrO4 due to the common ion effect.
The formation of which reaction products is increased in MBCD-treated MDR cells after exposure to 100 µM cholesterol? A.AMP + ADP B.ADP + Pi C.ATP + Pi D.ADP + ATP
B- Figure 2 shows that exposure of cholesterol-depleted MDR cells to 100 µM cholesterol results in complete restoration of ATPase activity (ATP hydrolysis). ATP hydrolysis produces ADP and inorganic phosphate.
Which approach does NOT measure the activity of the Na+K+ ATPase? A.Measuring the rate of ATP hydrolysis B.Measuring the free energy of the ion transport C.Measuring the rate of ADP production D.Measuring the change in ion concentration within the liposome
B- Free energy does not correlate with enzyme activity because it is not a measure of reaction rate/activity to measure the activity of the enzyme, we need to focus on kinetics of the reaction. reactions can be influenced by two factors: 1) stability of products (thermodynamics) 2) rate of product formation (kinetic factors) measuring free energy of ion transport is a thermodynamic property and enzyme activity is a kinetic property
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.
B- Grinding a heterogeneous catalyst increases the amount of catalyst available to the reaction and therefore increases its rate. finely grounded catalyst will have higher degree of interaction between the catalyst and reactant molecules
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.
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).
Based on the passage, in MSI CRC primary tumor cells, the size of the deletion in the HSP110 T17 microsatellite is inversely correlated with: A.the amount of HSP110ΔE9 protein expressed. B.the number of mature HSP110WT transcripts synthesized. C.the frequency of the omission of HSP110 Exon 9 during splicing. D.the extent of premature translation termination in Exon 10.
B- Table 1 shows that as the number of deleted base pairs (bp) increases from 3 to 8, the levels of HSP110ΔE9 increase whereas the levels of HSP110 decrease. This data indicates that there is an inverse relationship between the number of deleted bps and HSP110 levels
The graph below shows the relationship between the predominant form of iron as a function of solution pH and applied potential. Based on the graph, which of the following statements is true? A.At a potential of -0.4 V, as pH increases, Fe2+ is reduced and precipitates as Fe(OH)3. B.At a potential of -0.44 V, the equilibrium between Fe and Fe2+ is independent of solution pH below pH 6. C.At pH = 1, as the potential is changed from -0.2 to +0.8, Fe3+ is reduced to Fe2+. D.At pH = 8 and V = -0.1 V, Fe(OH)2 is the predominant form of iron.
B- The Pourbaix diagram for iron is given, but only one statement correctly conveys information presented by the diagram. At an applied potential of -0.44V and pH below 6, there is an equilibrium between Fe(s) and Fe2+(aq), as shown by the line of demarcation. The fact that this line moves horizontally with increasing pH up until pH = 6 means that this equilibrium is unaffected by changing the pH.
What are the hybridization states of the carbon atoms involved in the conversion of trans to cis retinal? A.sp B.sp2 C.sp3 D.sp3d
B- because cis and trans are alkenes which are trigonal planar and are sp2
Which mechanism best describes how P-gp facilitates drug resistance? A.P-gp binds to antitumor drugs in the presence of ATP and degrades the drugs. B.P-gp serves as a pump and uses active transport to move antitumor drugs outside the cell. C.P-gp prevents the entry of anti-tumor drugs into the cell. D.P-gp causes increased membrane permeability, which causes antitumor drugs to exit the cell.
B- because the passage mentioned it is a transporter that is ABC (ATP binding cassette) The passage notes that P-gp is an ABC transporter protein with ATPase activity. These transporters use ATP to actively transport molecules such as drugs out of the cell.
According to the information in the passage, HSP110 is most likely which type of protein? A.Adhesion B.Chaperone C.Clathrin D.Enzyme
B- chaperone proteins assist in folding parts of a protein which is consistent with the function of heat shock proteins. adhesion- proteins like glycoproteins that mediate cell-cell connections clathrin- works to form vesicles to assist in transport within cells
Harlequin ichthyosis, a rare genetic disorder, causes the skin to become thick and scaly. Flaking skin behind the eyelids of individuals with this condition is most likely to damage which structure of the eye? A.Choroid B.Cornea C.Lens D.Retina
B- flaking skin means the first layer or outermost layer which would be cornea choroid- located deep to sclera; won't be affected by outer layer
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.
B- homogenous catalyst will have same phase as products so it might not be possible to separate the products at the end of the reaction.
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
B- in gas-liquid chromatography, the first peak to emerge will be from a nonpolar or least polar compound. the alkene is nonpolar and least polar so it will elute first
Knowing that the speed of light in the vitreous humor is 2.1 × 108 m/s, what is the index of refraction of the vitreous humor? (Note: The speed of light in a vacuum is 3.0 × 108 m/s.) A.0.7 B.1.4 C.2.1 D.3.0
B- index of refraction n = c/v n = 3 x 10^8/ 2.1 x 10^8 n = 3/2 = 1.5 A- can't be true because light travels through a vacuum then a vitreous humor (fluid) C and D- can't be true
The findings described in the passage suggest that memory for locations: A.is comparable to adults by nine years of age. B.is influenced by categorical knowledge. C.becomes more accurate with age. D.relies solely on recall of distances.
B- the passage and result showed how adults had more central placement error which would suggest that categorical bias was observed
If a man with a mutant copy of Ace2 has a child with a woman that is heterozygous for the mutant Ace2 allele, what is the probability that the child will be a female and homozygous for the mutant Ace2 allele? A.0 B.0.25 C.0.75 D.1
B- the passage states that it is an X-linked mutation X' Y x X'X 1/2 chance of being a girl 1/2 chance of being homozygous 1/2 x 1/2 = 1/4 = 0.25
The information in the passage best supports the conclusion that Intron 8 of HSP110 most likely contains which of the following? A.Stop codon B.Splice acceptor site C.HSP110 gene promoter D.Partial coding sequence of HSP110
B- the passage talks about alternative splicing which allows mRNA to have different isoforms since introns don't contain any coding and are spliced out, B makes more sense
Based on the passage, which conclusion is best supported? A.Gender discrimination is more likely to occur than racial discrimination. B.Race and gender discrimination manifest in similar ways. C.The incidence of race and gender discrimination is equivalent. D.Minority women are especially subject to discrimination.
B- the table shows similar distribution across categories don't select an option that is not present in the passage
Which of the following diagrams does NOT illustrate a function of an automobile catalytic converter?
C- This response depicts a chemical transformation (SO3 → SO2 + H2O) that is NOT catalyzed by an automobile's catalytic converter. which is found in passage where it says SO2---> SO3 instead
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
C formula is given; just plug and chug 1/2 x 10^-2 + 1 = S 50 + 1 = S = 51 A and B- negative sign indicates diverging lens, whereas eye lens is converging
What is the product of the reaction of Compound 1 (shown below) with HBr by the pathway shown in Figure 3? Compound 1 A.(R)-1-bromo-1-deuteriohexane B.(S)-1-bromo-1-deuteriohexane C.(S)-1-bromo-1-deuteriopentane D.(R)-1-bromo-1-deuteriopentane
C- because original compound 1 is R, so SN2 reaction have inversion of sterochemistry which will give S A and B- wrong because it is pentane
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) B.3Al3+(aq) + 2Cu(s) → 3Al(s) + 2Cu2+(aq) C.2Al(s) + 3Cu2+(aq) → 2Al3+(aq) + 3Cu(s) D.3Al(s) + 2Cu2+(aq) → 3Al3+(aq) + 2Cu(s)
C- This response depicts the balanced chemical reaction that occurs when the four substances [Al(s), Al3+(aq), Cu(s), and Cu2+(aq)] are mixed.
In addition to glucose, what other monosaccharide is part of the UDP-glucose structure? A.Xylose B.Fructose C.Ribose D.Arabinose
C- UDP has ribose and with both OH cis arabinose- has trans OH
What is the relationship between Pp, PMPA, and Pd? A.Pp = PMPA + 3Pd B.Pp = 3PMPA + Pd C.Pp = 3PMPA − 3Pd D.Pp = PMPA − 3Pd
C- Pmpa = pd + (ps - pd)/ 3 pmpa - pd = (ps - pd)/ 3 3pmpa - 3pd = ps - pd 3pmpa - 2pd = ps Pp = ps - pd Pp = 3pmpa - 2pd - pd Pp = 3pmpa - 3pd
Which of the following will decrease the percentage ionization of 1.0 M acetic acid, CH3CO2H(aq)? A.Chlorinating the CH3 group B.Diluting the solution C.Adding concentrated HCl(aq) D.Adding a drop of basic indicator
C- adding HCl (strong acid) will shift the equilbrium towards reactant side and will decrease ionization of acetic acid
The term "ideal gas" refers to a gas for which certain assumptions have been made. Which of the following is such an assumption? A.The law PV = nRT2 is strictly obeyed. B.Intermolecular molecular forces are infinitely large. C.Individual molecular volume and intermolecular forces are negligible. D.One gram-mole occupies a volume of 22.4 L at 25°C and one atmosphere pressure.
C- A property of an "ideal" gas is that it is composed of particles that have negligible volume and do not exert intermolecular forces. D- is wrong because STP means one mole of gas occupies 22.4 L at 0 C and 1 atm
What is the total number of fused rings present in a steroid? A.1 B.2 C.4 D.6
C- A steroid is composed of a 6-6-6-5 fused ring assembly, which is a total of 4 fused rings
Why is the velocity of blood flow slower in capillaries than in arteries? A.Capillary walls are more elastic than arterial walls. B.Capillaries have less resistance to blood flow than arteries. C.The total cross-sectional area of capillaries exceeds that of arteries. D.Blood pressure is higher in the capillaries than in arteries.
C- A1v1 = A2v2 (continuity equation) because we have high number of capillaries means that we have large total cross-sectional area which would mean small velocity A- velocity is determined by cross-sectional area not by elasticity; also capillaries are not elastic because they are smaller and only have single celled walls B- R = p l/ A resistance need: vessel length, vessel radius, and blood viscosity because capillaries have smaller radii, it's resistance is high D- blood pressure is higher in arteries
The data in Figure 1 show that: A.the unfolding of LipA proteins is a non-reversible process. B.exposure to high temperature eliminates any variant protein activity. C.variation in the flexible regions of LipA decreases the temperature sensitivity of activity. D.wild-type LipA loses all activity when first heated to 50°C.
C- Figure 1 shows that temperature has less effect on the enzymatic activity of the variants than wild-type LipA.
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)? A.Thiol side chains that can hydrogen bond B.Long alkyl tail that exhibits predominantly London forces C.Side chains whose net charge responds to pH D.Covalent linkages that reversibly hydrolyze
C- In order for pH to affect self-assembly of Compound 1, there must be side chains whose net charge respond to pH. At pH 4, there is a smaller net negative charge, self-assembly; at pH 8, the net negative charge is much higher, causing repulsion of Compound 1 molecules and blocking self-assembly.
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.
C- Laforin will cleave off phosphate groups from glycogen, thus removing radioactive phosphate from the WT band and decreasing the intensity of the band.
Which reaction is catalyzed by LipA? A.ATP hydrolysis B.Peptide bond cleavage C.Hydrolysis of triacylglycerides D.Transfer of carboxyl groups
C- LipA is a lipase, which hydrolyzes triacylglycerides.
Based on the data presented in the passage, which statement best describes the HSP110ΔE9 allele? A.Cancer-promoting and dominant to HSP110WT B.Cancer-promoting and recessive to HSP110WT C.Cancer-suppressing and dominant to HSP110WT D.Cancer-suppressing and recessive to HSP110WT
C- So theres two parts to this answer. From Fig. 1 we can see that it is cancer-suppressing because the tumor volume was decreased in HSP110deltaE9, but we see that it is dominant to the WT allele, because the results from the combined HSP110WT & HSP110deltaE9 (100%) in the "heat shock-induced protein aggregation" column is similar to that of the HSP110deltaE9 (96%) vs HSP110WT(64%)
What type of functional group is formed when aspartic acid reacts with another amino acid to form a peptide bond? A.An amine group B.An aldehyde group C.An amide group D.A carboxyl group
C- The functional group that represents a peptide bond is called an amide group.
Which nucleotide pairing(s) would be recognized by the MMR system during DNA replication? dTMP and dCMP dGMP and dAMP dAMP and dTMP A.I only B.III only C.I and II only D.I, II, and III
C- The passage indicates that MMR system recognizes the pair mismatch. Both options I and II represent mismatches, thus they will be recognized by the MMR system.
Considering the structure of STN, what is the most likely mechanism for its entry into the cell? A.Active transport B.Receptor mediated endocytosis C.Diffusion directly through the membrane D.Passage through an ion channel
C- The structure of STN shows that it is a hydrophobic molecule. These types of molecules can pass through the membrane by simple diffusion and therefore do not need a transporter.
What aspect of Experiment 1 does NOT address whether membrane composition has an effect on Na+K+ ATPase activity? The activity of the Na+K+ ATPase: A.showed less temperature dependence in the 14:1 liposome than the 14:0 liposome. B.was highest in the 14:0 liposomes at all temperatures. C.increased with temperature in both the 14:1 liposome and the 14:0 liposome. D.was greater at all temperatures when cholesterol was present.
C- increased activity in both composition does not address if composition has an effect on ATPase activity; C is also not comparing the composition
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.
C- is correct because Cpd A + CN- ----> malic acid----> aspartic acid D- out because absence of water B- some not all A- not mentioned in the passage and also temp was raise to increase the rate of the reaction
The source of the phosphate groups that are added to rhodopsin is: A.arrestin. B.rhodopsin kinase. C.ATP. D.all-trans-retinol.
C- kinases phosphorylate a molecule and rhodopsin kinase catalyzes the transfer of phosphate group from ATP. the source therefore is ATP
Participants in a weight-loss program agree to have their body mass index (BMI) measured to track their progress in the program. Among a sample of 72 participants, the mean BMI is 30 and the median BMI is 25. Which statement provides an accurate description of the sample? A.More participants had a BMI over 25 than a BMI under 25. B.The majority of participants had a BMI between 25 and 30. C.Half of the participants had a BMI over 25 and half had a BMI under 25. D.More outliers among the participants had a BMI under 25 than a BMI over 30.
C- median represents the middle of the distribution, splitting the sample distribution of values in half.
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
D- the figure 1 y axis is ml/min so convert 9L/10 min---> mL/min 9 x 10^3 ml/10 min---> 900 ml/min look at the figure: at 900 ml/min---> power is 200 W P x t = E 200 W x 10 min x 60 s/1min = E 200 x 600 = E 2 x 6 x 10^4 12 x 10^4 J = E 120 kJ = E
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) A.9.2 × 10-12 J B.1.6 × 10-16 J C.1.1 × 10-18 J D.4.0 × 10-19 J
D- E = hf 6.6 x 10^-34 x 6 x 10^2 x 10^12 40 x 10^-20 J 4 x 10^-19 J THz = 10^12 Hz
What fraction of a 15O sample decays in 10 min? A.1/8 B.9/16 C.3/4 D.31/32
D- half life is 2 min in 10 min---> 10/2 = 5 half lives (1/2)^5 1/2 x 1/2 x 1/2 x 1/2 x 1/2 1/ 4x4 x2 1/16 x 2 = 1/32 remains 31/32 decayed
By what factor is the proton concentration increased in the experiments shown in Figure 1B from those shown in Figure 1A? A.2 B.10 C.200 D.1000
D- pH 7 to pH 4 3 pH apart 10 x 10 x 10 = 1000
A circuit similar to that in Figure 2 is set up. It has a potential of 2.0 V. Assume that the resistance in the circuit is negligible compared to that of the lightbulb. Approximately how much current passes through the lightbulb? A.0.5 A B.1.0 A C.2.0 A D.4.0 A
D V= IR V/R = I 2 V/ 1/2 R = I I = 4 A ignore the negligible bit; it's simply saying that resistance is same
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 D.−4
D asking for change so, go to table 1: variant XI: R33G +1 ---> 0 (-1) K112D +1---> -1 (-2) M134D 0---> -1 (-1) Y139C 0---> 0 I157M 0---> 0 -1 + -1 + -2 = -4 we need change in charge like +1 to 0 has -1 difference
What is the most likely location of P-gp within the plasma membrane? A.Associated with lipids on the cytoplasmic side only B.Associated with lipids on the extracellular side only C.Peripheral to the plasma membrane D.Within a lipid raft
D cholesterol rich domains are lipid rafts; also we can eliminate first 2 options because specific side was never discussed.
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)
D reaction 3 H2O2 + I- -------> IO- + H2O reaction 4 H2O2 + IO- -------> H2O + O2 + I- Net rxn: 2H2O2 -----> 2H2O + O2
What is the function of the Na+K+ ATPase during a neuronal action potential? A.Stimulation of the action potential B.Depolarization of the membrane C.Hyperpolarization of the membrane D.Restoration of the resting potential
D- ATPase restores and maintains resting potential by moving 3 Na+ out and 2 K+ in A- stimulation occurs by neurotransmitters that bind to ligand gated channels B- depolarization occurs due to opening of voltage gated Na+ channels which is an independent function C- this occurs after action potential has taken place
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.
D- An enzyme stabilizes the transition state, thus lowering the activation energy of a reaction.
If 2-pentanol replaces 1-pentanol in the reaction shown in Figure 3, the rate of substitution is less because: A.the C-O bond in 2-pentanol is stronger than the C-O bond in 1-pentanol. B.there is a competing elimination reaction that slows the rate of substitution. C.there is more steric hindrance at the oxygen atom in 2-pentanol than in 1-pentanol, making protonation less likely. D.there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of 1-pentanol.
D- At a secondary carbon, there is more crowding from the adjacent carbon chains, which makes nucleophilic substitution slower. A- C-O in alcohol is weaker and this is not relevant B- competing elimination does not slow the rate of substitution. their rates are independent C- steric hindrance is not on oxygen
Which effect did a protein-free diet have on DSS-treated +/y and -/y mice, respectively? A.Both the +/y and the -/y mice gained weight. B.The +/y mice lost weight, and the -/y mice gained weight. C.The +/y mice gained weight, and the -/y mice lost weight. D.Both +/y and the -/y mice lost weight.
D- Based on Table 1, both mice genotypes lost weight when fed a protein-free diet: WT lost 22% and mutants lost 20%.
Assuming no mutations to the signaling pathway described in the passage, what event directly activates CARD11? A.Proteolytic cleavage B.GTP binding C.Membrane association D.Phosphorylation
D- Based on the passage, the protein that activates CARD11 is a protein kinase. This implies that phosphorylation is the activating event.
During the initiation of muscle contraction, mysosin binds actin after troponin binds to which ion? A.H+ B.K+ C.Na+ D.Ca2+
D- Ca2+ ions play a critical role in myosin-actin binding during skeletal muscle contraction. Ca2+ binds to troponin and allows tropomyosin to move, freeing the site of interaction between actin and myosin
The intensity of the radiation emitted by the oxygen sensor is directly proportional to the: A.propagation speed of the radiation. B.wavelength of the radiation. C.polarization of photons emitted. D.number of photons emitted.
D- E = hf E is directly proportional to the number of photons, intensity of radiation
What volume of a 0.120 M CaI2 solution would contain 0.078 mol of the solute? A.35.0 mL B.65.0 mL C.350 mL D.650 mL
D- In order to obtain the volume of solution necessary to provide a given amount of solute in moles, one needs to take the number of moles and divide by the solution concentration in molarity: 0.078 mol × 1 L/0.120 mol = 0.65 L = 650 mL.
Acetic acid and ethanol react to form an ester product as shown below. 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.
D- Labeling the oxygen in ethanol with O-18 definitely determines which -OH is lost because 100% of the O-18 in radiolabeled ethanol will be retained in the ester, not the water. Thus, only acetic acid supplies -OH that is lost to form water. A and B- changing hydrogens won't tell if OH is lost or not C- carbonyl oxygen is not going to move
Colchicine is a drug that prevents the formation of microtubules. Which of the following mitotic processes would NOT occur after exposure to this drug? A.Formation of new cell plate B.Replication of DNA during interphase C.Breakdown of the nucleolus during prophase D.Movement of the chromosomes toward opposite poles of the cell during anaphase
D- Microtubules bind to chromosomes at the level of the kinetochore and regulate their migration toward the opposite poles of the cell during anaphase.
Which of the following types of orbitals of the central atom are involved in bonding in octahedral compounds? A.sp B.sp3 C.p D.d2 sp3
D- Octahedral compounds have six σ bonds and no stereochemically active lone pairs. According to valence bond theory, the central atom requires the hybridization of six atomic orbitals, d2sp3.
A researcher suggests that the effect of the testing condition on the affiliation ratings is caused by increased sympathetic nervous system activity due to performing a repetitive behavior. Is this explanation likely to be supported? A.Yes, because studies show that increased sympathetic nervous system arousal can affect how people feel about others. B.Yes, because the design used in Study 1 allows researchers to establish the effect of sympathetic nervous system arousal on affiliation ratings. C.No, because performing repetitive behaviors is more likely to increase parasympathetic nervous system activity. D.No, because both of the conditions involve repetitive behaviors, but participants' ratings differ under the two conditions.
D- Participants in both the synchronous and asynchronous conditions engaged in repetitive activities. Therefore, if differences in the affiliation ratings had been caused by sympathetic nervous system arousal, only the synchronous condition would have been affected.
The environment of the retinal binding site is most likely: A.hydrophilic. B.positively charged. C.negatively charged. D.hydrophobic.
D- Retinal is composed of mainly carbon and hydrogen, making it largely hydrophobic.
When concentrated urine is being produced, in which of the following regions of the kidney will the glomerular filtrate reach its highest concentration? A.Proximal convoluted tubule B.Distal convoluted tubule C.Cortical portion of the collecting duct D.Medullary portion of the collecting duct
D- The collecting duct is the final structure in which water reabsorption occurs, which concentrates filtrate. The medullary portion of the collecting duct is the last portion of the tubules where reabsorption can occur. In the portion of the tubule that follows, there will be no more reabsorption. Thus, the medullary portion of the collecting duct contains the most concentrated glomerular filtrate that will correspond to the urine.
Which of the following statements does NOT correctly describe the dehydration of malic acid to fumaric acid and maleic acid? A.The reaction occurs most readily with tertiary alcohols. B.The reaction involves the loss of a water molecule. C.The reaction has a carbocation intermediate. D.The reaction is stereospecific.
D- The formation of two products (fumaric and maleic acid) tells us the reaction is not stereospecific because stereospecific reaction won't produce a mixture A- dehydration likes tertiary alcohols especially if it is E1 reactions B- yes, dehydration is loss of water C- during dehydration rxn, carbocation forms
MBCD is composed of which type of molecule? A.Amino acids B.Fatty acids C.Nucleotides D.Carbohydrates
D- The passage notes that MBCD is a cyclic oligosaccharide, indicating that it is composed of carbohydrate molecules.
Compared to normal glycogen, the amount of what type of bond is decreased in Lafora bodies? A.Phosphomonoester B.Phosphodiester C.α-1,4-Glycosidic bond D.α-1,6-Glycosidic bond
D- The passage stated that Lafora bodies have sparse branching compared to normal glycogen. In glycogen, branching is due to the formation of α−1, 6-glycosidic bonds. Thus, these bonds are decreased in Lafora bodies.
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
D- This option is correct because according to Ohm's law, current is equal to voltage divided by resistance. In order to increase the current when the voltage is fixed, the resistance must be decreased, such as by replacing the lightbulb with one that has a resistance of 0.2 Ω instead of 0.5 Ω.
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
D- only Asp and Arg can have electrostatic interaction with cells; they are at the end which is cell adhesion region
Suppose squares 1, 2, 3, and 4, moving from left to right at the top of the grid light up and some participants think "top row lights up first," to remember the sequence. Which process is most likely being used to enhance working memory capacity? A.Divided attention B.Priming C.Automatic processing D.Chunking
D- organizing parts into meaningful wholes
Which structure represents a phosphorylated subunit of glycogen as described in the passage?
D- passage states phosphate groups covalently linked to C2 and C3
A researcher replicates the experiment with the addition of a physical stressor to the first phase of the experiment. According to Selye's general adaptation syndrome, this change is: A.necessary, because humans respond differently to different types of stressors. B.necessary, because physical stressors cause avoidance-avoidance conflict, whereas social stressors cause approach-approach conflict. C.unnecessary, because the human stress response is not specific to the type of stressor. D.unnecessary, because both physical stressors and social stressors cause avoidance-avoidance conflict.
Seyle's general adaptation syndrome three stages: alarm: fight or flight resistance: built up when noxious challenge is detected as continuing exhaustion: will cause death if the body is unable to overcome threat theory states that stress is perceived as a threat (distress) and may be debilitating if it is continuous C- GAS states that every stress response follows a similar course regardless of the nature of stressor
According to Maintenance Factor 1, mild changes in bodily sensations act as: A.unconditioned stimuli. B.conditioned stimuli. C.unconditioned responses. D.conditioned responses.
the passage mentioned "mild changes in bodily sensations (such as slightly heightened heartbeat) with the panic they experienced during panic attacks;" since bodily sensations are associated with panic attacks. it is a conditioned stimuli B
Data on the role of Maintenance Factor 1 on Panic Disorders is LEAST likely to come from which type of research? A.Correlational studies B.Case studies C.Longitudinal studies D.Experimental studies
mild changes in bodily sensations (such as slightly heightened heartbeat) with the panic they experienced during panic attacks; this leads to conditioned fear in response to changes in bodily sensations (Maintenance Factor 1). this suggests that it would unethical to do experimental studies D longitudinal studies describes a research study that follows the population or group of interest at multiple time points. this would actually be helpful to track the effect of panic attacks and conditioned fear over time.
According to the developed chromatography plate shown below, what is the approximate Rf value of aspartic acid? A.0.20 B.0.50 C.5 D.10
solvent front 10 units aspartic acid 2 units Rf = distance traveled by solute/solvent front Rf = 2/10 = 1//5 = 0.2
