AAMC CP volume 2
Which technique could researchers have used to most selectively bind Protein X on a column and elute it in a purified form? Pass the crude protein mixture through a porous column matrix:
A- of cation exchange resin and elute Protein X with a NaCl gradient. B- of hydrophobic interaction resin and elute Protein X with a NaCl gradient. C- of gel filtration beads and elute Protein X with the buffer described in the passage. D- with covalently bound dsDNA oligomer and elute Protein X with a NaCl gradient. Although cation exchange will certainly separate Protein X from other proteins of dissimilar net charge, it will not selectively bind to Protein X on the column resin. Although hydrophobic interaction chromatography could purify Protein X, it will not selectively bind to Protein X on a column. Although gel-filtration or size-exclusion chromatography will separate proteins based on molecular weight, it will not selectively bind to Protein X on the column. This technique is affinity chromatography and depends on the selective binding of the immobilized dsDNA oligomer to Protein X.
According to the Arrhenius equation, how does an increase in temperature affect the rate constant of a reaction?
According to the Arrhenius equation, as temperature increases, more molecules have the necessary energy to overcome the activation energy barrier, leading to an increase in the rate constant.
Which characteristic is most important when choosing an indicator for an acid-base titration?
An appropriate indicator for an acid-base titration ensures that its color change occurs within the pH range corresponding to the titration's equivalence point.
What is the number of hydrogen bond donors in XA?
Based on the chemical structure of XA provided in Figure 1, there are three hydroxyl groups, one of which is part of the carboxylic functional group, capable of forming a hydrogen bond with an acceptor.
What is the balanced half-reaction that produces succinic acid (C4H6O4) from fumaric acid (C4H4O4)?
C4H4O4 + 2H+ + 2e-----> C4H6O4
What is the classification of neutral atoms of the chemical element found in plaques in the left ventricle based on its magnetic properties?
Ca has electron configuration [Ar]4s2 which is diamagnetic because paired electrons but since Ca has magnetic field present on it, it will have d orbital which will make it [Ar]4s13d1 which is paramagnetic
In terms of valency, metal/nonmetal classification, and ion type, what is the best description of the ion that induces conformational changes in CaM?
Calcium is Ca+2 which means divalent cation
According to Charles's law, what happens to the volume of an ideal gas when the absolute temperature is doubled while the pressure and moles remain constant?
Charles's law indicates that the volume of an ideal gas is directly proportional to its absolute temperature at constant pressure, so if the temperature doubles, the volume also doubles.
The protocol for CaM labeling by Compound 1 includes a step where Compound 4 is added to the reaction mixture. Why is this step needed?
Compound 4 (N-acetylmethionine) is a functional analog of the protein's methionine residues, so it is expected to react with the excess of Compound 1 once all accessible methionine residues are modified.
What is the electron configuration for the metal ion used to obtain the 1H NMR spectrum?
Cu+2 is used [Ar] 4s13d10 neutral Cu 1 removed from 4s and 1 from 3d [A] 3d9
What is the approximate percentage of fluorine by mass in Compound 1?
2 Flourine atoms 19 x 2 = 38 g/mol total MM = 250 g/mol 38/ 250 ---> 40/300 ---> 1.5 x 10^-1 x 100 15%
How many electrons are transferred when going from Compound 5 to Compound 6?
2 double bonds are formed in cpd 6 which means 4 electrons are lost 1 double bond = 2 e- loss
The equation describes a transverse wave that propagates along the x-axis. y (x,t) = 24 cm x sin2pi (x/8cm - t/2s) What is the propagation speed of the wave?
24 cm ---> amplitude 2pi/ 8 cm ---> wavenumber number 8 is wavelength t/2s ---> angular frequency c (speed) = wavelength x f c = 8 cm x 1/2 s = 4 cm/ s
What is the minimum radiation energy absorbed in two seconds by 20 grams of heart tissue that is associated with the formation of plaques?
4 x 10^-2 Gy/s x J/ kg / Gy = 4 x 10^-2 J /kg . s 20 g / 10^3 g x 1 kg x 4 x 10^-2 J /kg . s x 2s 2 x 4 x 2 = 16 x 10^ -4 J 1.6 mJ
What is the IC50 of Compound 2 in nanomolar?
72 microM---->nM 72 x 1000 ---> 72 x 10^3 nM
What is the approximate molecular weight in kDa of a protein composed of 90 amino acid residues?
90 amino acid x 110 Da = 9900 Da or 9.9 kDa
Which trend in electronegativity is observed when moving from the bottom of a group to the top of the periodic table?
Electronegativity increases due to a decreased number of filled electron shells.
How many non-canonical base-paired guanines are found in the total stack of the Spinach RNA aptamer?
Four guanine base pairs are shown in Figure 1, which is one of 2 G-quadruplexes; therefore, there are 8 non-canonical base-paired guanines in Figure 1. 2 x4 8
Which compound is formed instead of Compound 2 if NaBH4 is also added in Step 1, shown in Figure 1?
NaBH4 is reducing agent which removed a double bond from compound 2
How many Lewis bases coordinate the K+ ion associated with the G4-tetrads in Figure 1?
One K+ ion in the central cavity is coordinated by 8 carbonyl oxygens, the Lewis bases. The passage states that one K+ ion is in the center of the two stacked G4-tetrads.
What would replacing residue 65 (α1 subunit), residue 97 (β2 subunit), residue 157 (β2 subunit), and residue 205 (β2 subunit) with Ala most likely eliminate in terms of the type of receptor binding to GABA?
Phenylalanine (F) and tyrosine (Y) each contain an aromatic group in their side chain. Without an aromatic side chain, there are no cation-π interactions with GABA.
Which type of enzyme catalyzes a reaction that directly activates or deactivates enzyme activity by covalent enzyme modification?
Protein Kinases phosphorylate enzymes directly activating or deactivating them cAMP is second messenger that activates/deactivates enzymes, is not direct ATP synthase activates/deactivates enzyme but is not direct
What is the highest level of protein structure present in Protein X in the absence of DNA?
Protein X contains multiple, interacting secondary structures and therefore has tertiary structure.
Which type of column chromatography was mentioned in the passage?
Purification of HKT relies on the strong and selective interaction (affinity) between histidine tags of the protein and the resin charged with Ni2+. Because the Ni2+ metal is immobilized in the resin, this type of chromatography is known as immobilized metal affinity chromatography (IMAC).
How much heat must be added to 200. g of liquid water to increase its temperature by 5.00 K? (Note: The specific heat capacity of liquid water is 4.18 J•g-1•K-1.)
Q= mcat Q= 2 x 10^2 x 4.18 x 5 Q= 4.18 x 10^3 Q= 4180 J
What is the ground state electron configuration of the metalloid atom in the polymers used for the manufacturing of AIOL?
Si electron configuration [Ne] 3s2 3p2
What is the number of neutrons in the metalloid atom present in the compound in the polymers used for the manufacturing of AIOLs?
Si was used and it has 14 protons and mass number = 28 so neutrons = 28 - 14 = 14 neutrons
A hollow cube floats half submerged in oil of density 800 kg/m3. The cube edges are marked every 1 cm. What is the minimum density of a liquid that can be determined by reading the mark at which the cube floats?
The cube sinks in a fluid having a density less than the cube density and no mark can be read then. Because the cube floats half submerged in oil of density 800 kg/m3, the cube density is ½ × 800 kg/m3 = 400 kg/m3, according to Archimedes' principle.
What is the approximate isoelectric point of the C-terminal amide-capped tripeptide Asp-Ala-Cys-NH2? (Note: pKa of N-terminus = 9.8; pKa of Asp side chain = 3.9; pKa of Cys side chain = 8.4.)
The isoelectric point (pI) for two neutral side chains that ionize to a negative charge when there is only an unmodified N-terminus is calculated as follows: pI = (pKa of the Asp side chain + pKa of the Cys side chain)/2 = (3.9 + 8.4)/2 = 6.15 ≈ 6.1.
How much Co2+-Compound 2 was added to the agar plate?
The passage states that 20 μL of the metal-Compound 2 complexes were added to the agar plates, and the solution's original concentration was 100 μg/mL. This means that 0.020 mL × 100 μg/mL = 2 μg.
What is the approximate ratio of Compound 1 and its conjugate acid at pH 6.5?
The passage states that the pKa value of Compound 1 is 5.5. Using the Henderson-Hasselbalch equation, pH - pKa = log([A-]/[HA]), which gives 6.5 - 5.5 = 1 = log([A-]/[HA]), where [A-] = [Compound 1] and [HA] = [Compound 1-H] as the neutral form. The ratio of [A-]/[HA] can be determined via 10^1.0 = 10:1.
What is the highest level of protein structure presented in the enzyme used for the kinetic resolution in Step 2?
The passage states that there are interactions between the parallel twisted β-sheets and α-helices, which indicates a tertiary protein structure. also, CAL-B is monomeric protein which means it can't be quartenary structure
Which conclusion can be reached regarding the stereoselectivity of Step 2 in Figure 1?
The process was highly selective, as evidenced by the high % ee of both products, which indicates a strong preference for one enantiomer over the other, demonstrating selectivity.
Which conditions are required for the correct positioning of Compound 1 in the G4-tetrad as shown in Figure 2? Compound 1 must have:
The proper orientation of anionic Compound 1, shown in Figure 2, requires E-stereochemistry. The high priority groups on the alkene carbon are N and the phenyl-C, and they are "entgegen" (E), not "zusammen" (Z).
What is the appearance of the methyl group protons in the 1H NMR spectrum of (R)-Compound 1?
The single hydrogen at C1 will split the 1H NMR signal of the methyl hydrogens at C2 into a doublet because of the (n + 1) rule, where n is the number of adjacent hydrogens. With n = 1, (n + 1) becomes 2, and 2 signals defines a doublet. CH3- OH CH3- doublet
Which property makes mercury better suited than water for use in clinical capillary thermometers?
Thermometers measure temperature based on coefficient of thermal expansion and on the capillary effect which is enhanced when surface tension is larger. Mercury surface tension exceeds that of water by approximately 7 times, meaning it is 7 times more likely for mercury to rise in the capillary tube of a thermometer than water. Additionally, the mercury thermal expansion coefficient is similar to that of water.
What is the molar mass of CaM after its reaction with one equivalent of Compound 1?
This number results from the addition of 96 g/mol (the molar mass of the adduct C4H4N2O) to the molar mass of unmodified CaM (16621 g/mol) and corresponds to the m/z value (with z normalized to +1) for the first peak in the mass-spectrum of CaM modified in the absence of calcium ions (Figure 2).
After the workup for product isolation in Step 1 was completed, why was a vacuum distillation performed?
Using a vacuum produces a lower pressure, which lowers the boiling point of product and impurities, providing for an efficient separation/purification.
Vector A has the reciprocally orthogonal components Ax = +3, Ay = +4, and vector B has Bx = -6, By = -8. What is the magnitude of vector S = A + B?
Vector S has components Sx = Ax + Bx = -3, Sy = Ay + By = -4. The magnitude of S is Sqrt of 3^2 + 4^2 = sqrt of 25 = 5
Which instrumental technique would be most appropriate to determine the information presented in Table 1?
X- ray crystallography- could provide a sufficiently high resolution protein structure to determine specific noncovalent interactions between the ligand and receptor circular dichroism- most appropriate to study secondary structure composition mass spec- measure protein's molar mass and primary structure of protein fragments UV spec- at wavelength 280 nm, useful for estimating protein concentration
What is the IUPAC name for the product of the Fub8-catalyzed reaction of Compound 10?
aldehyde with R group -(CH2)4 C---CH so a seven-carbon chain (hept-) with a triple bond (-yne) on the sixth carbon and an aldehyde group (-al) on the first carbon.
What are the E/Z designations for Compound 1?
both E designations because The alkene between C1 and C2 has two substituents with the highest priority substituents on either side of the double bond on opposite sides. This is also true for the alkene between C6 and C7.
What explains the fact that the USW used for the emulsification of the opaque eye lens have a frequency of 30 MHz? (Note: Use propagation of ultrasound waves 1500 m/s.)
c = wavelength x frequency c/ f = w 15 x 10^2 / 3 x 10 x 10^6 5 x 10^2/10^7 5 x 10^2-7 5 x 10^-5 m m ---> mm (multiple by 1000) 0.05 mm
Which compound is most appropriate to accomplish the synthesis in Figure 2?
carboxylic acid (no charge) ---> carboxylic (neg charge) or carboxylate salt happens because carboxylic acid is deprotonated which occurs in base so NaOH
Which vitamin is a cofactor for Fub7 to form Compound 2?
compound 2 has a lot of nitrogen groups so pyridoxine which B6; also the passage states that Fub 7 is pyridoxal phosphate dependent vitamin A- insoluble for eyes; not a precursor for any coenzyme vitamin B5- pantothenic acid for CoA vitamin C- ascorbic for skin; ot a precursor for any coenzyme
What is the elemental classification of the catalyst for the conversion of Compound 2 to Compound 3 in Figure 1?
copper is used as a catalyst which is transition metal
What best approximates the typical number of electrons generated per second by the X-ray detectors that receive the transmitted low-energy X-rays? (Note: Use elementary charge 1.6 × 10-19 C.)
electrons/ seconds ? C = I/e e = I / C e = 15 x 10^-6 C/s/ 1.6 × 10-19 C e = 15 /1.6 x 10^13 e = 15 x 2/3 x 10^13 e = 10 x 10^13 e = 9 x 10^13 (since I rounded down, the answer should be rounded down)
What is the structural relationship between Compound 4 and the structure shown?
enantiomers non-superimposable mirror images of each other and differ in spatial orientation
An electrically isolated thin spherical shell of radius 3 cm is made of a metal of work function 5 eV. What is the maximum number of photoelectrons that the sphere can emit when exposed to a beam of photons of energy 7 eV each? (Note: Use 4.8 x 10^-8 V.)
energy of ejected photoelectrons KE = Photon Energy - Work Function = 7eV-5eV = 2eV The potential is given by 4.8 x 10^-8 V. N (max number of electrons) x e x V < KE N = KE/eV N = 2eV/ 4.8 x 10^-8 eV. N= 1/ 2.4 x 10^-8 0.4 x 10^8 4 x 10^7
What is the nearest location of an object that can be seen clearly by a patient wearing the AIOL described in the passage?
find p q = all the distance which is 3 cm (focal length) + 5mm (distance between retina and AIOL) 3 cm + 5 mm/ 10 mm x 1 cm 3 cm + 0.5 cm 3.5 cm = q 1/f = 1/q + 1/p (solve for p) p = fq/q-f p = 21 cm
What is the distance between the AIOL and the retina when the patient can clearly see an object located at infinity?
focal length = 3cm asking what is q (distance between AIOL and the retina when object is at infinity) if q is smaller than focal length = object will be behind the retina if q is larger than focal length = object will be front of the retina 1/f = 1/q + 1/p (infinity) 1/f = 1/q f = q f = 3cm
Based on Figure 1, 40 minutes after lethal CO(g) exposure, how much lower is the lactate concentration in Ngb variant-treated blood versus albumin-treated blood?
go to figure 1: Albumin is around 12 mM Ngb variant-treated is around 8 mM 12 mM- 8mM = 4 mM
Assuming product release is rate determining, which compound in Table 1 provides the highest catalytic efficiency for Fub8?
high kcat and low km cpd 7 because it has the highest kcat/km ratio
What is the enzyme classification of lysozyme?
hydrolase because lysozymes hydrolyzes glycoside bonds
What is the maximum number of full α-helical turns in a protein monomer composed of 4428 amino acid residues?
in a-helix has 3.6 amino acid per turn so, 4438/3.6 which if I round 3.6 down to 3 4438/3 = 1476 which means real answer is rounded down than 1476 which is 1230
What is the complementary sequence to the DNA oligomer described in the passage?
in the passage (5′-CTAGCGCGCTAG-3′) (5' - CTAGCGCGCTAG-3')
Which physical effect constitutes the basis on which the X-ray detectors for CT scan operate?
in the passage, based on the number of X-ray photons collected, each detector generated an electric current which is photoelectric effect doppler effect- change in the frequency as the source and observer move relative to each other - when the source moves toward you--> high f and low wavelength (compressed) = high pitch - when the source moves away from you---> low f and high wavelength (stretched) = low pitch mass-energy conversion- refers to nuclear fission or fusion Venturi effect- fluid speed increase and pressure decreases when it goes through narrow section of a pipe - as the pipe narrows, the fluid must move faster to maintain flow - faster moving fluid exerts less pressure (due to energy conservation) - like pinching a hose
To which region of the electromagnetic spectrum does the laser radiation described in the passage belong?
in the passage, laser pulses at 532 nm wavelength visible light is from 400 nm (blue) to 750 nm (red) Gay X-Men Using Viagra In My Room Gamma, X-ray, UV, Visible, Infrared, Microwave, Radio High frequency Low frequency
Which amino acid stabilizes the [Fe4S4] and [NiFe4S4] clusters in CODH?
in the passage, "these clusters are held in place within the protein by complexation of four metal centers to thiolate ligands of amino acid residues." thiolate indicates cysteine also, the figure shows a lot Sulfur interaction
In which region of the electromagnetic spectrum does Compound 2 absorb?
in the passage, it states strong absorption band at wavelength 423 nm which is within visible spectrum because visible spectrum is from 400 to 750 nm infrared is 750 nm-0.01 cm UV is 100 nm to 400nm X-ray is 0.2 nm to 10nm
What is the chemical classification of the element detected in the left ventricle when the absorbed dose per unit time exceeded 0.04 Gy/s?
in the passage, it's Calcium which is alkaline earth metal because it is in group 2
During the purification of the Ngb variant, which technique would most likely discover fractions that contained low concentrations of intact Ngb variant? Collect each fraction in a test tube, get a positive chemical test result for protein on a drop of solution, and keep:
in the passage, laser absorbed is 532 nm wavelength which is close to green also heme protein is red and light absorbs the green light
What was the partial pressure of CO(g) at the lethal level used by the researchers?
in the passage: 3.0% by volume CO(g) (a lethal concentration) in 760 mmHg air Partial Pressure = X (mole fraction) times Total Pressure PP = 3/100 x 760 mmHg PP = 22.8 mmHg Volume is directly proportional n (moles) at constant P and T
What is the gap between the atomic energy levels that correspond to the emission of therapeutic high-energy X-rays? (Note: Use h = 6.6 × 10-34 J•s.)
in the passage: frequency = 1.5 x 10^17 Hz E = hf E = 6.6 x 10^-34 J.s x 1.5 x 10^17 1/s E = 9.9 x 10^-17 J
Which type of chromatographic purification of Ngb-H64Q-CCC was performed in the second purification step?
in the passage: step 1: purified by gel filtration column step 2: column filled with porous cellulose beads covalently attached to poly L -lysice which selectively binds bacterial endotoxin step 3: elution through beads that associate with hydrophobic regions step 1: size exclusion chromatography step 2: affinity chromatography step 3: hydrophobic interaction normal phase chromatography involves a polar stationary phase like silica gel
What is the maximum magnitude of the work done by the focusing muscles on the AIOL? (Note: The force on the AIOL is constant, has a magnitude of 2.0 μN, and points in the direction of the AIOL displacement.)
it is only asking for Work and gave us force W = F d same direction means cos 0 = 1 W = 2 x 10^-6 N x 5 x 10^-3 m (from the passage) W = 1 x 10^-8 J
After a neutralization workup, which reagent is needed to produce the compound shown from Compound 1 in the presence of pyridine?
ketone to alcohol is done acid chloride or acetyl chloride
What is the approximate chemical shift of the CH3 hydrogen atoms in Compound 1?
methyl is singlet so it should be around 3-4 ppm but because it is next to Oxygen---> it is 1-2 ppm
Which inhibition mechanism is exhibited by Compound 2 against HKT?
mixed inhibition because vmax went up and km went up all the lines in a Lineweaver-Burk plot for a mixed inhibitor do not share the same slope or x- and y-intercepts.
One mole of ideal gas undergoes a thermodynamic process in which pressure doubles and volume halves. What is the value of the molar heat capacity of the gas during the process?
molar heat capacity is C=Q/ΔT ideal gas law = PV = nRT Question description P1 = 2P2 V1 = 1/2V2 PV =nRT P1V1 = nRT= 2P2 1/2V2 P1V1=P2V2 nRT1 = nRT2 T1= T2 ΔT = 0 so C = Q/0 means infinity
In the crystallography study, which substance must be added to 100 mL of 0.1 M isocyanic acid to ensure that 99.9% of it exists as the conjugate base?
need more base because pH needs to be significantly higher than the pka of isocyanic acid so adding NaOH
How many stereoisomers does Compound 1 have?
one chiral center so 2^n = 2
What is the ratio of [OH-] to [H+] in the buffer described in the passage?
pH = 5 for buffer [H+] = 10^-5 M [OH-] = 10^-14/ [H+] [OH-] = 10^-9 [OH-]/ [H+] 10^-9/10^-5 10^-4 : 1
Which polymer listed in Table 1 is best suited for the fabrication of an AIOL?
relative volume change in lens formula Volume change=3×coefficient of thermal expansion (CTE)×ΔT polymer 1 and polymer 2 seems to be in competition polymer 1 VC = 3 x 2 x 10^-5 x 2 VC = 12 x 10^-5 x 100 VC = 0.012 % polymer 2 VC = 3 x 3 x 10^-5 x 2 VC = 18 x 10^-5 x 100 VC= 0.018% both are with 0.020% limit so now it comes down attenuation number which means if high attenuation number = less light to pass through so polymer 2 wins
Which amino acid residue in Protein X would most likely form electrostatic interactions with the DNA backbone in the minor groove?
reside 24 because it is positively charged and is found in B sheet minor grove Arg24 (R24) is a positively charged amino acid in the β3 region that interacts with the minor groove of the DNA, and therefore it can form bonds with the negatively charged phosphate backbone.
Momentum is defined as mass multiplied by speed. If a large mass object and a small mass object have the same momentum, which object has the larger kinetic energy?
small mass momentum (p) = m x v small mass x big velocity = p KE = 1/2 mass x velocity^2
What is the ideal bond angle of a molecule with an sp2-hybridized central atom?
sp- 180 sp2- 120 sp3- 109.5 sp3d2- 90
Which heterocycle, present in the side chains of residues 93 and 261, helps stabilize the carbonite ion, CO22-, attached to cluster C?
the figure shows that 93 and 261 is histidine and histidine has imidazole ring furan is like pyrrole but attached to oxygen instead of nitrogen indole is found in tyrptophan pyridine is benzene like but Nitrogen attached to carbons
What is the temperature in °C for both steps in Figure 1?
the passage says: 298 K 298-273 = 25 C
Which amino acid in CaM is expected to be responsible for binding the ion that triggers conformational changes in the protein?
the passage states that calcium ions interact with acidic amino acid side chains which are Aspartate
Which carboxylic acid is formed after the diol tautomerizes along the reduction path from CO2 to CO?
the passage states that dihyroxycarbene (HO-C-OH) can be tautomerized into a carboxylic acid which is (HO-HC=O) formic acid. carbamic acid (H2NCO2H) acetic acid (CH3CO2H) chloroformic (ClCO2H)
What is the Kb of 3-HK?
the pka is 1 so ka = 10^-1 which means kb = 10^-13
According to Table 1, which metal-Compound 2 complex was most effective against B. subtilis?
the table measures the inhibition zone so highest number is more effective which is Zn+2
Assuming ideal gas behavior, what is the volume of CO2 gas captured by a 1 μg (0.015 nmol) CODH crystal under standard conditions?
there are two Ni clusters in each CODH unit and Ni/CO2 is 1:1 so finding the volume of one will be equal to the other under ideal gas standard conditions. Volume = 22.4 L/mol 1.5 x 10^-11 (given) mols are mols of 2 units so we need to half it 22. 4 x 3 x 10^-11 = 67.2 x 10^-11 6.72 x 10^-10 mols
What is the equilibrium constant expression for Protein X binding to the dsDNA oligomer (dsDNA)?
two X protein binds to one molecule of dsDNA Based on the passage, the binding reaction is 2(Protein X) + dsDNA ⇌ (Protein X)2(dsDNA). Thus, to write the equilibrium constant expression, [product] raised to its stoichiometric coefficient (1) must be in the numerator, and the product of the concentration of each [reactant] raised to their stoichiometric coefficients must be in the denominator.
What is the percentage of the Vmax attained for a single-substrate enzyme following Michaelis-Menten kinetics at [S]0 = 4 × KM?
v = vmax [S]/ km + [S] v = vmax 4 km/ km + 4km v = 4 vmax km / km (1+4) v = 4/5 vmax 4/5 = 0.8 vmax or 80% vmax
An object is moved up with constant speed on an inclined plane that makes angle θ with the horizontal. The coefficient of kinetic friction is μ. What is the expression of the mechanical advantage MA?
Friction's Relation to Weight: Weight (Gravitational Force): The weight mg always acts vertically downward, but we break it into two components: Parallel to the incline: mgsinθ (this is the component that pulls the object down the incline). Perpendicular to the incline: mgcosθ (this is the component pressing the object against the surface, affecting normal force and thus friction). The correct formula for MA is: MA= Output Force/ Input Force =sinθ/sinθ+μcosθ This means: MA= 1 /sinθ+μcosθ
How many chiral centers does the receptor's ligand have?
GABA is a four-carbon carboxylic acid chain with a terminal amine. As such, it has no chiral centers.
What is the daughter nucleus of the radioactive that undergoes alpha decay?
He packet so mass number - 4 atomic number -2 223-4 = 219 88n-2 = 86
Which neuronal potential would represent hyperpolarization?
Hyperpolarization yields a more negative neuronal potential, and -75 mV is more negative than the equilibrium potential.
What is the role of pyridine in Step 1 of Figure 1?
In the reaction mechanism for Step 1 of Figure 1, pyridine accepts the proton from the hydroxyl group acylated by acetic anhydride, thus acting as a proton acceptor, which is a Brønsted-Lowry base.
The Kd for 1:1 O2(g) binding by the Ngb variant described in the passage is 2.5 × 10-8 M. What is the KA(CO) for this Ngb variant?
Kd is the dissociation constant Ka is the association constant Kd and Ka are inversely proportional passage gives us: M = Ka CO/ Ka O2 Kd for O2 is 2.5 x 10^-8 1/Kd = Ka O2 so, 1/ 2.5 x 10^-8 M Ka O2 = 0.4 x 10^8 -M M x Ka O2 = Ka CO 10^4 x 0.4 x 10^8 M^-1 = KaCO 0.4 x 10^12 M^-1 4 x 10^11 M-1
What is the equilibrium constant of Reaction 1?
Keq = Products/ Reactants keq= kf / kr keq = 12/ 4 x 10^4 keq = 3 x 10^-4 The reaction gives us reduction (products) is 12 s^-1 and oxidation (reactants) is 40,000 s^-1
What is the effect of a temperature increase on the dimensions of the opening through which the X-rays for CT scan pass?
L =L a T as T increases, L increases D = D aT as T increase, D (width) increase but since in the passage: D = 1 x 10^-6 m L = 10 x 10^-6 m L is bigger D so L increases more than D as the temp increases
An electrically charged particle enters a uniform magnetic field at a speed of 500 km/s. What is the quantity, if any, whose magnitude must be known in order to calculate the speed of the particle in the magnetic field?
Lorentz force- force that is charged particle experiences when it moves in an electric or magnetic field; always perpendicular to particle's velocity and magnetic field direction electric force- F = q x E (electric field strength) magnetic force- F = q v B sin0 (0 - angle between velocity and magnetic field) F = FE + FB = q E + q (v x B), when v and B are at a right angle nothing affects the speed bcz speed remains constant in the magnetic field Other factors like electric fields, external forces, or changing magnetic fields can alter the speed.
Which single modification to this Venturi meter increases the maximum air flow speed at the entrance that can be measured?
venturi meter measures the speed of air flow. U-shaped tube tracks the pressure change caused by air speed the height difference in the liquid columns corresponds to the air speed Shortening the tube: This limits how high the liquid can rise, reducing the range of speeds it can measure. (Wrong answer) Increasing the liquid density: A denser liquid makes the height difference in the tube smaller for the same air speed. This allows the meter to handle higher air speeds without overflowing. (Correct answer) Increasing the liquid amount: Adding more liquid increases the resistance to movement, reducing the air speed range the meter can measure. (Wrong answer) Decreasing the liquid amount: Less liquid means the meter can't handle high speeds before the liquid runs out of the tube. (Wrong answer)
What is the color of the emitted fluorescence light upon activation of Compound 1 by the Spinach RNA aptamer?
wavelength at which it emits light is 501 nm which closer to 400 nm end so around green light green-- 490-570 nm yellow-- 570-585 nm orange- 580-620 nm red-- 650-750 nm ROYGBIGV 750-----400nm
If two half-cells were made using the intracellular and extracellular chloride concentrations described in the passage and connected by a salt bridge, would there be a voltage difference, and why?
yes, because this is a concentration cell A concentration cell only requires a difference in ion concentrations to create a voltage difference. this can't be galvanic cell because no redox reaction is occuring
Which type of turn in a protein has a hydrogen bond between the i and i + 5 end residues of the turn?
π-turn has a hydrogen bond between the i and i + 5 end residues of the turn. α-turn has a hydrogen bond between the i and i + 4 end residues of the turn. β-turn has a hydrogen bond between the i and i + 3 end residues of the turn. γ-turn has a hydrogen bond between the i and i + 2 end residues of the turn.
