NS2: CPF

Question 1

partial pressure

Answer 1

For a gas that is a component in a mixture of gases, partial pressure is defined as the pressure that this gas would exert if it took up the same volume by itself.

Dalton’s law states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of its components.
Pgas = XgasPtotal
where Pgas is the partial pressure and Xgas is the mole fraction of a gas but Xgas = ngas/ntotal if more information is needed

Question 2

Raoult’s Law

Answer 2

the presence of solute in a mixture decreases its vapor pressure

P = XAPA°
where P is the vapor pressure of the solution, XA is the mole fraction of the solvent, and PA° is the vapor pressure of the pure solvent

Explains why adding solute makes things harder to boil; water molecules have a harder time breaking through to the surface in the presence of more solute

Question 3

Conservation of Energy

Answer 3

states that energy can neither be created nor destroyed, just transferred from one form to another.

KEinitial + PEinitial = KEfinal + PEfinal

If we need to account for nonconservative forces such as friction, we can do so using the equation Etotal – Enonconservative = Efinal

E = PE + KE

Question 4

Hemoglobin

• function
• composition
• graph

Answer 4

metalloprotein that plays an essential role in gax exchange in humans, transporting oxygen to the body tissues and carbon dioxide to the lungs for exhalation. They are found in erythrocytes and consists of four globular protein subunits, forming a quaternary structure; each subunit contains one heme group that contains one iron cation capable of binding oxygen in the Fe2+ state.

• • With four subunits containing one heme each, each hemoglobin can carry up to four oxygen atoms
• • Binding of oxygen to ANY OF THE FOUR binding sites causes an increase in oxygen affinity of the remaining sites → aka COOPERATIVITY

Cooperative binding can be recognized by its signature sigmoidal or S-shaped curve → for hemoglobin-oxygen binding, the y axis is usually the percent saturation of oxygen, while the x axis is the partial pressure of oxygen

Question 5

The Bohr Effect

Answer 5

dictates why oxygen is dropped off at the tissues despite the supposedly high affinity it has to the hemoglobin.

The higher the partial pressure of oxygen, the higher the oxygen saturation tends to be

Under certain conditions (ie low plasma pH and increased levels of CO2), this binding curve can shift toward the right along the x-axis and decrease the hemoglobin-oxygen affinity, allowing oxygen to be more easily dropped off in the tissues

Question 6

States of matter

Answer 6

Solids: fixed shape; fixed volume, thus are incompressible; no flow, but particles do vibrate in place

Liquids: fixed volume; no fixed shape, thus can flow to assume the shape of their container; has viscosity (resistance of movement)

Gas: no fixed volume or shape, thus able to be compressed (meaning density of a given gas is not constant and varies based on its container)

Question 7

Phase Changes

• 6 types
• exo or endo?

Answer 7

Endothermic: require input of heat bc breaks bonds or intermolecular interactions

• • Melting / fusion = solid → liquid
• • Evaporation = liquid → gas
• • Sublimation = solid → gas

Exothermic: release heat bc of bond formation or increase in IMF strength

• • Condensation = gas → liquid
• • Freezing = liquid → solid
• • Deposition = gas → solid

Question 8

Define the following:

• solubility
• saturated soln
• supersaturated soln

Answer 8

Solubility: degree to which a solute (particles) dissolves in a solvent (fluid substance); solubility of ionic substances in water increases with temperature, while the opposite pattern is observed for gases (bc higher temperatures provide gases w more kinetic energy that they can use to escape the soln)
– Like dissolves like

Saturated soln: when the maximum amount of solute that can be dissolved has been added

Supersaturated soln: heating of a saturated soln in order to dissolve more solute, then cooling it

Question 9

PV = nRT explained

Answer 9

Pressure of a gas given as Pascals (Pa), atmospheres (atm), mmHg, or torr → 1 atm = 760 mmHg = 760 Torr = 105 Pa (N / m2)

Volume: 1L = 103 mL = 103 cm3

Mole: given as 6 x 1023 atoms / molecules of a substance

R: universal gas constant

Temperature: provides info of avg KE of the molecules in a gaseous sample, where T ~ KEavg = ½ mv2

• • T may be given in degrees Celsius or Kelvin → Tk = Tc + 273
• • Absolute zero (0 K) is the lowest temperature that any substance can exist, and at this temperature, the molecules in a gaseous sample will have no energy and will be motionless

Question 10

titration

Answer 10

process of finding the concentration of an unknown solution (analyte) by reacting it w a soln of known concentration (titrant)

Flat regions of titration curves represent buffering solutions (roughly equal mix of an acid/base and its conjugate base)

At equivalence points during the titration (steep, near-vertical sections of the curve), the number of acid or base groups added to the soln is equivalent to the number of base / acid groups in the original unknown soln → NaVa = NbVb, where N and V are the normality (mol/L) and volume of the acidic and basic solutions, respectively

Titrant is added to the analyte until the endpoint, either by reaching a certain pH value (acid-base reactions) or when a precipitate appears (precipitation reactions)
– For acid-base reactions, an indicator generally undergoes a color change near the desired pH → eg. phenolphthalein changes color above a pH of 7 when a strong base is being titrated by a weak acid

Question 11

Functional Groups, set 1

• Alkanes
• Alkenes
• Alcohols
• Aldehydes
• Ketones
• Carboxylic Acids

Answer 11

Alkanes: hydrocarbon w only single C-C bonds
Alkenes: hydrocarbon w at least one C=C double bond
Alcohols: RC–OH
Aldehydes: RC(=O)H)
Ketones: RC(=O)R’
Carboxylic acids: R(C=O)OH

Question 12

Functional Groups, set 2

• Amides
• Esters
• Acid Anhydrides
• Acid Halides
• Amines
• Imines
• Enamines

Answer 12

Amides: R(C=O)NR’R’’
Esters: R(C=O)OR’
Acid anhydrides: R(C=O)O(C=O)R’
Acid halides: R(C=O)X
Amines: R–NH2, R–NHR’, or R-NR’R”
Imines: R=NH or R=NR’
Enamines: C=C–NH2, C=C–NHR, or C=C–NRR’

Question 13

Functional Groups, set 3

https://quizlet.com/140558809/mcat-functional-groups-and-symbols-flash-cards/

Answer 13

YOU SHALL NOT PASS WITHOUT DOING ALL OF THESE; mark as “1” until you get all of them

Question 14

Percent Dissociation

eg. Given 2 moles of HF in 0.1 L of water, provide % diss.

Answer 14

percent of original acid concentration that has divided into ions

Original [HF] = 2 moles / 0.100 L = 20 M

[H+]/[HF] = (10-4 M H+) / (20 M HF) = 5 x 10-6

% dissociation = 5 x 10-6 x 100% = 5 x 10-4
THUS,
% dissociation = 5 x 10-4% = 0.0005%

Question 15

Isomers; two types

Answer 15

molecules w the same number of atoms but different connectivity or spatial arrangement

Structural isomers: diff connectivity

• • Chain isomers: diff arrangements of the carbon backbone
• • Functional Isomers: molecular formula is the same but different functional group
• • Positional isomers: same functional group but different location

Stereoisomers: different spatial arrangement

• • Cis-trans: most common isomerism involving alkenes bc rotation about pi bond is restricted, thus substituents are given priorities
• —- Cis / Z isomer: highest priority groups for each carbon are on the same side of the molecule
• —-Trans / E isomer: opposite sides

Question 16

Optical isomers

Answer 16

come in pairs and typically contain one or more chiral centers

Enantiomers: non-superimposable mirror images w similar chemical and physical properties but polarize light in opposite directions → eg. your hands

Diastereomers: multiple chiral centers but isomers only differ at some; similar chemical but less similar physical properties

Question 17

Chiral Carbon labelling:

Answer 17

Lowest priority pointed away form observer; rest will be numbered 1 → 3 in a decreasing priority order (ie highest priority is numbered first)

If counterclockwise, then S chiral center

If clockwise, then R chiral center

Question 18

Work

Answer 18

Work is measured in joules and the work-energy theorem tells us that Wnet = ΔKE.

Question 19

Power

Answer 19

Power is defined as work divided by time (P = W/t). Its units are watts (W), and 1 W = 1 J/s.

Rearranging the units of J/s indicates that power can also be expressed as a constant force multiplied by a constant velocity (P = Fv).

Question 20

Electromagnetic waves

Answer 20

transverse waves that can propagate through vacuum, as well as through other media such as air and water; have both electrical and magnetic components, with amplitudes perpendicular to each other and to the direction in which the wave is propagating

EM waves propagate through space at the speed of light (c = 3 × 108 m/s)

Question 21

EM Wave Equations (2)

Answer 21

The standard unit for all EM radiation is the magnitude of the wavelength (nm), which is measured btwn two successive peaks
The corresponding frequency of the wave is the number of complete wavelengths that pass a given point per second. Frequency is usually measured in hertz (Hz).

v = λf
Thus, longer wavelengths correspond to lower-frequency radiation, and shorter wavelengths correspond to higher-frequency radiation.

E = hf = hc/λ)
where h is the Planck’s constant
– An increase in frequency produces a proportional decrease in wavelength, with a corresponding increase in the energy of the photons that compose the light.
– Upon entering a new medium, the velocity and wavelength of light change while the frequency remains unchanged.

Question 22

Define the following:

• isotype

- half-life

Answer 22

Isotope: varieties of an element that differ by the number of neutrons in its nucleus; share the same atomic number and chemical properties → often used in radiolabeling techniques

Half-life (t1/2): time required for half of the parent isotope of the sample to decay into daughter (radiogenic) isotopes → 100% to 50% (1 half life) to 25% (2) to 12.5% (3) to 6.25% (4) to 3.125% (5) to 1.0625% (6)

Question 23

extractions

Answer 23

technique used to separate two or more compounds in solution by manipulating their solubility properties using acid-base chemistry

Setup usually has a layer of less-dense organic solvent on top of a layer of water, which is a highly polar compound → non polar compounds will move to organic layer, while polar / charged ones will remain in the aqueous layer

Question 24

Mono- /Poly- atomic ion nomenclature

- u should alrdy kno oxyanion nomenclature

Answer 24

Monatomic ions use the suffix -ide, as in hydride (H−) or oxide (O2−)

Polyatomic Ion nomenclature:

The ion with the lesser charge will use the suffix “-ous,” and the ion with the greater charge will use the suffix “-ic.”
– Eg. iron (II) cation, Fe2+, is termed the ferrous ion, while the iron (III) cation, Fe3+, is the ferric ion

If the polyatomic anion includes a hydrogen (H+) ion, “hydrogen” or the prefix “bi-” is added to the name of the parent anion.
– Eg. CO32− ion is carbonate, so HCO3− can be termed hydrogen carbonate or bicarbonate

“dihydrogen” denotes the presence of two H+ ions
– Eg. H2PO4− can be called dihydrogen phosphate

Question 25

Oxidative Phosphorylation concepts

Answer 25

final major process of aerobic respiration; ultimate function is to synthesizes ATP

Begins w series of chemical reactions (aka ETC) to a final electron acceptor, oxygen → THIS IS THE ONLY TIME IN EUKARYOTIC AEROBIC RESPIRATION WHERE OXYGEN IS DIRECTLY REQUIRED; used in order to accept the electrons removed from NADH and FADHs (formed in glycolysis and Krebs), thus being transformed into water

Question 26

ETC mech

Answer 26

The ETC is composed of four large protein complexes (Complexes I-IV) embedded in the inner mitochondrial membrane and two small electron carriers shuttling electrons between them

• • Complex I is known as NADH dehydrogenase
• • II is known as succinate dehydrogenase
• • III is known as cytochrome bc or c
• • IV is known as cytochrome c oxidase

Energy released from the electron transfers of the ETC are used to pump H+ across the membrane, causing a gradient for them to re-enter as protons through an ATP synthase. This proton movement generated 90% of the ATP synthesized during oxidative phosphorylation.

Question 27

Ka/Kb relationship w solubility

Answer 27

A higher Ka is associated with stronger acidity, meaning it dissociates easily. A higher Kb is associated with stronger basicity, meaning it will also dissociate easily.

A strong acid or base dissociates completely in water, while a weak acid or base dissociates incompletely.

Question 28

Determine the following, relative to each other:

• Circular motion
• Centripetal force
• Centripetal acceleration
• Frequency
• Period

Answer 28

Circular motion refers to the motion experienced by an object travelling in a circular path.

• • Caused by centripetal force → F = mv2/r → looks similar to F = ma
• • Centripetal acceleration = v2/r

Frequency is equal to revolutions per second and has units of hertz (Hz), or s−1.

• • Since frequency refers to revolutions per second and velocity is most commonly measured in meters per second, converting between the two requires only the knowledge of the number of meters that corresponds to one revolution.
• • To find this, one must use the equation for the circumference of, or distance around, a circle; this equation is circumference = 2πr.
• • Multiplying frequency (revolutions per second) by circumference (meters per revolution) yields a velocity value with the proper units: meters per second.

Period is the inverse of frequency, meaning that it refers to the number of seconds required to make one revolution and has units of seconds.

Question 29

Suicide inhibition

building on previous flashcard on inhibition

Answer 29

Suicide inhibition occurs when an enzyme binds the inhibitor (structurally a substrate analogue) and forms an irreversible complex with it, usually through a covalent bond. This can involve the inhibitor being chemically modified by the enzyme during the normal course of catalysis to produce a reactive group that is specifically responsible for the formation of the irreversible inhibitor-enzyme complex.

Question 30

Translation

• goal
• structures involved

Answer 30

process by which mRNA sequence is translated into a protein w each codon corresponding to an amino acid

Things involved:
– Transfer RNA, or tRNA, is a relatively small RNA molecule characterized by a hairpin structure that is responsible for “translating” between codons and amino acids.
– Ribosome, primarily made up of ribosomal RNA (rRNA); contains multiple rRNA strands with associated proteins, and have two major components
—– large subunit (50S in prokaryotes and 60S in eukaryotes) → catalyzes the formation of the polypeptide chain
—– small subunit (30S in prokaryotes, 40S in eukaryotes) → reads the RNA
overall sizes of 70S for the prokaryotic ribosome and 80S for the eukaryotic ribosome

Question 31

Translation steps

Answer 31

has the same 3 steps as transcription lol

1) Initiation occurs when the mRNA sequence binds to the small ribosomal subunit, either at a region in the 5’ untranslated region known as the Shine-Dalgarno sequence (in prokaryotes) or to the 5’ cap in eukaryotes.
- - The first tRNA is known as the initiator tRNA, and it binds to the start codon (AUG). The initial amino acid is methionine in eukaryotes, but N-formylmethionine in prokaryotes.
- - Once this happens, initiation factors facilitate the binding of the small ribosomal subunit to the large ribosomal subunit, forming the initiation complex.

2) During elongation, the ribosome reads the mRNA in the 5’ to 3’ direction and synthesizes a polypeptide from its N terminus to its C terminus, which is one of the reasons why amino acid sequences are traditionally written in the N-to-C order.
- - Proteins known as elongation factors help move this process along.
- - Three main binding sites are involved in elongation:
- —- The A site contains the next aminoacyl-tRNA complex
- —- The P site a peptide bond is formed between the growing polypeptide chain and the incoming amino acid
- —- The tRNA, which is now no longer “charged” with an attached amino acid, briefly pauses at the E site and detaches from the mRNA

3) After all of the charged tRNA sequences have been translated, translation is terminated.

Question 32

Define the following:

• fluid dynamics
• viscosity
• laminar flow
• turbulent flow

Answer 32

Fluid dynamics: study of fluid flow; relevant to blood flow

Viscosity: resistance to flow or deformation by shear stress

Laminar flow: corresponds to smooth, well-behaved flow that is easy to model

Turbulent flow: the smoothly regulated layers of laminar flow break down

Question 33

Pouiseulle’s Law

Answer 33

describe laminar flow of incompressible fluids through a long cylindrical tube → involves the flow rate (Q), the pressure drop between both ends of the tube (ΔP), the radius of the tube (r), the length of the tube (L), and the viscosity (η)

Main idea: flow rate is directly proportional to radius to the fourth power

Question 34

Bernoulli’s Equation

Answer 34

essentially conversation of energy for fluids
P1 + ½ ρv12 + ρgh1 = P2 + ½ ρv22 + ρgh2

Main idea: when height is constant (as in a horizontal pipe system), an increase in velocity corresponds to a decrease in pressure, and vice versa

Question 35

Continuity Equation

Answer 35

v1A1 = v2A2

Main idea: within a closed system, the flow rate of a liquid is constant, which indicates that the velocity of the fluid (v) is inversely proportional to the cross-sectional area that it is flowing through

Question 36

why does blood shoot out of the body when an artery is cut

Answer 36

blood will obviously shoot out of the body as a result of blood pressure. That pressure is converted to kinetic energy, causing the blood to move rapidly as it exits the body.

Question 37

VSEPR Theory

Answer 37

uses Lewis structures and electronic relationships to determine the shapes of molecules, assuming that the distance between electron-rich regions will be maximized due to electronic repulsions

The number of regions of electron density is determined by the number of bonds and lone pairs around the central atom

Question 38

Structures of the VSEPR theory

Answer 38

Tetrahedral molecules contain four electron-rich areas and four bonded atoms, at angles of 109.5°.

Trigonal pyramidal molecules likewise have four electron-rich areas, but only three are bonded atoms and the fourth is a lone pair.

Bent molecules, like H2O, have two bonded atoms and two lone pairs. The bond angles in trigonal pyramidal molecules and bent molecules (107° and 104.5°, respectively) are slightly smaller than the 109.5° angle found in tetrahedral molecules.

Trigonal planar molecules, like BF3, have three electron-rich areas and three bonded atoms at 120° angles

Linear molecules, such as CO2, have two electron-rich areas and two bonded atoms.