Medical College Admission Test (MCAT)

4A: Translational motion, forces, work, energy, and equilibrium in living systems

Translational Motion (PHY)

▪ Units and dimensions

▪ Vectors, components

▪ Vector addition

▪ Speed, velocity (average and instantaneous)

▪ Acceleration

Force (PHY)

▪ Newton’s First Law, inertia

▪ Newton’s Second Law (F = ma)

▪ Newton’s Third Law, forces equal and opposite

▪ Friction, static and kinetic

▪ Center of mass

Equilibrium (PHY)

▪ Vector analysis of forces acting on a point object

▪ Torques, lever arms

Work (PHY)

▪ Work done by a constant force: W = Fd cosθ

▪ Mechanical advantage

▪ Work Kinetic Energy Theorem

▪ Conservative forces

Energy of Point Object Systems (PHY)

▪ Kinetic Energy: KE = (1/2)mv^2; units

▪ Potential Energy

o PE = mgh (gravitational, local)

o PE = (1/2)kx^2 (spring)

▪ Conservation of energy

▪ Power, units

Periodic Motion (PHY)

▪ Amplitude, frequency, phase

▪ Transverse and longitudinal waves: wavelength and propagation speed

4B: Importance of fluids for the circulation of blood, gas movement, and gas exchange

Fluids (PHY)

▪ Density, specific gravity

▪ Buoyancy, Archimedes’ Principle

▪ Hydrostatic pressure

o Pascal’s Law

o Hydrostatic pressure; P = ρgh (pressure vs. depth)

▪ Viscosity: Poiseuille Flow

▪ Continuity equation (A∙v = constant)

▪ Concept of turbulence at high velocities

▪ Surface tension

▪ Bernoulli’s equation

▪ Venturi effect, pitot tube

Circulatory System (BIO)

▪ Arterial and venous systems; pressure and flow characteristics

Gas Phase (GC, PHY)

▪ Absolute temperature, K, Kelvin scale

▪ Pressure, simple mercury barometer

▪ Molar volume at 0 C and 1 atm = 22.4 L/mol

▪ Ideal gas

o Definition of ideal gas

o Ideal Gas Law: PV = nRT

o Boyle’s Law: PV = constant

o Charles’ Law: V/T = constant

o Avogadro’s Law: V/n = constant

▪ Kinetic Molecular Theory of Gases

o Heat capacity at constant volume and at constant pressure (PHY)

o Boltzmann’s Constant (PHY)

▪ Deviation of real gas behavior from Ideal Gas Law

o Qualitative & quantitative (Van der Waals’ Equation)

▪ Partial pressure, mole fraction

▪ Dalton’s Law relating partial pressure to composition

4C: Electrochemistry and electrical circuits and their elements

Electrostatics (PHY)

▪ Charge, conductors, charge conservation

▪ Insulators

▪ Coulomb’s Law

▪ Electric field E

o Field lines

o Field due to charge distribution

▪ Electrostatic energy, electric potential at a point in space

Circuit Elements (PHY)

▪ Current I = ΔQ/Δt, sign conventions, units

▪ Electromotive force, voltage

▪ Resistance

o Ohm’s Law: I = V/R

o Resistors in series

o Resistors in parallel

o Resistivity: ρ = R•A/L

▪ Capacitance

o Parallel plate capacitor

o Energy of charged capacitor

o Capacitors in series

o Capacitors in parallel

o Dielectrics

▪ Conductivity

o Metallic

o Electrolytic

▪ Meters

Magnetism (PHY)

▪ Definition of magnetic field B

▪ Motion of charged particles in magnetic fields; Lorentz force

Electrochemistry (GC)

▪ Electrolytic cell

o Electrolysis

o Anode, cathode

o Electrolyte

o Faraday’s Law relating amount of elements deposited (or gas liberated) at an electrode to current

o Electron flow; oxidation and reduction at the electrodes

▪ Galvanic or Voltaic cells

o Half-reactions

o Reduction potentials; cell potential

o Direction of electron flow

▪ Concentration cell

▪ Batteries

o Electromotive force, voltage

o Lead-storage batteries

o Nickel-cadmium batteries

Specialized Cell ― Nerve Cell (BIO)

▪ Myelin sheath, Schwann cells, insulation of axon

▪ Nodes of Ranvier: propagation of nerve impulse along axon

4D: How light and sound interact with matter

Sound (PHY)

▪ Production of sound

▪ Relative speed of sound in solids, liquids, and gases

▪ Intensity of sound, decibel units, log scale

▪ Attenuation (damping)

▪ Doppler Effect: moving sound source or observer, reflection of sound from a moving object

▪ Pitch

▪ Resonance in pipes and strings

▪ Ultrasound

▪ Shock waves

Light, Electromagnetic Radiation (PHY)

▪ Concept of Interference; Young’s double-slit experiment

▪ Thin films, diffraction grating, single-slit diffraction

▪ Other diffraction phenomena, X-ray diffraction

▪ Polarization of light: linear and circular

▪ Properties of electromagnetic radiation

o Velocity equals constant c, in vacuo

o Electromagnetic radiation consists of perpendicularly oscillating electric and magnetic fields; direction of propagation is perpendicular to both

▪ Classification of electromagnetic spectrum, photon energy E = hf

▪ Visual spectrum, color

Molecular Structure and Absorption Spectra (OC)

▪ Infrared region

o Intramolecular vibrations and rotations

o Recognizing common characteristic group absorptions, fingerprint region

▪ Visible region (GC)

o Absorption in visible region gives complementary color (e.g., carotene)

o Effect of structural changes on absorption (e.g., indicators)

▪ Ultraviolet region

o π-Electron and nonbonding electron transitions

o Conjugated systems

▪ NMR spectroscopy

o Protons in a magnetic field; equivalent protons

o Spin-spin splitting

Geometrical Optics (PHY)

▪ Reflection from plane surface: angle of incidence equals angle of reflection

▪ Refraction, refractive index n; Snell’s law: n1 sin θ1= n2 sin θ2

▪ Dispersion, change of index of refraction with wavelength

▪ Conditions for total internal reflection

▪ Spherical mirrors

o Center of curvature

o Focal length

o Real and virtual images

▪ Thin lenses

o Converging and diverging lenses

o Use of formula 1/p + 1/q = 1/f, with sign conventions

o Lens strength, diopters

▪ Combination of lenses

▪ Lens aberration

▪ Optical Instruments, including the human eye

4E: Atoms, nuclear decay, electronic structure, and atomic chemical behavior

Atomic Nucleus (PHY, GC)

▪ Atomic number, atomic weight

▪ Neutrons, protons, isotopes

▪ Nuclear forces, binding energy

▪ Radioactive decay

o α, β, γ decay

o Half-life, exponential decay, semi-log plots

▪ Mass spectrometer

▪ Mass spectroscopy

Electronic Structure (PHY, GC)

▪ Orbital structure of hydrogen atom, principal quantum number n, number of electrons per orbital (GC)

▪ Ground state, excited states

▪ Absorption and emission line spectra

▪ Use of Pauli Exclusion Principle

▪ Paramagnetism and diamagnetism

▪ Conventional notation for electronic structure (GC)

▪ Bohr atom

▪ Heisenberg Uncertainty Principle

▪ Effective nuclear charge (GC)

▪ Photoelectric effect

The Periodic Table ― Classification of Elements Into Groups by Electronic Structure (GC)

▪ Alkali metals

▪ Alkaline earth metals: their chemical characteristics

▪ Halogens: their chemical characteristics

▪ Noble gases: their physical and chemical characteristics

▪ Transition metals

▪ Representative elements

▪ Metals and nonmetals

▪ Oxygen group

The Periodic Table ― Variations of Chemical Properties with Group and Row (GC)

▪ Valence electrons

▪ First and second ionization energy

o Definition

o Prediction from electronic structure for elements in different groups or rows

▪ Electron affinity

o Definition

o Variation with group and row

▪ Electronegativity

o Definition

o Comparative values for some representative elements and important groups

▪ Electron shells and the sizes of atoms

▪ Electron shells and the sizes of ions

Stoichiometry (GC)

▪ Molecular weight

▪ Empirical vs. molecular formula

▪ Metric units commonly used in the context of chemistry

▪ Description of composition by percent mass

▪ Mole concept, Avogadro’s number NA

▪ Definition of density

▪ Oxidation number

o Common oxidizing and reducing agents

o Disproportionation reactions

▪ Description of reactions by chemical equations

o Conventions for writing chemical equations

o Balancing equations, including redox equations

o Limiting reactants

o Theoretical yields

5A: Unique nature of water and its solutions

Acid-Base Equilibria (GC, BC)

▪ Brønsted-Lowry definition of acid, base

▪ Ionization of water

o Kw, its approximate value (Kw = [H+][OH–] = 10^–14 at 25 C, 1 atm)

o Definition of pH: pH of pure water

▪ Conjugate acids and bases (e.g., NH4+ and NH3)

▪ Strong acids and bases (e.g., nitric, sulfuric)

▪ Weak acids and bases (e.g., acetic, benzoic)

o Dissociation of weak acids and bases with or without added salt

o Hydrolysis of salts of weak acids or bases

o Calculation of pH of solutions of salts of weak acids or bases

▪ Equilibrium constants Ka and Kb: pKa, pKb

▪ Buffers

o Definition and concepts (common buffer systems)

o Influence on titration curves

Ions in Solutions (GC, BC)

▪ Anion, cation: common names, formulas, and charges for familiar ions (e.g., NH4+ ammonium, PO_4^3– phosphate, SO_4^2– sulfate)

▪ Hydration, the hydronium ion

Solubility (GC)

▪ Units of concentration (e.g., molarity)

▪ Solubility product constant; the equilibrium expression K_sp

▪ Common-ion effect, its use in laboratory separations

o Complex ion formation

o Complex ions and solubility

o Solubility and pH

Titration (GC)

▪ Indicators

▪ Neutralization

▪ Interpretation of the titration curves

▪ Redox titration

5B: Nature of molecules and intermolecular interactions

Covalent Bond (GC)

▪ Lewis electron dot formulas

o Resonance structures

o Formal charge

o Lewis acids and bases

▪ Partial ionic character

o Role of electronegativity in determining charge distribution

o Dipole moment

▪ σ and π bonds

o Hybrid orbitals: sp3, sp2, sp, and respective geometries

o Valence shell electron pair repulsion and the prediction of shapes of molecules (e.g., NH3, H2O, CO2)

o Structural formulas for molecules involving H, C, N, O, F, S, P, Si, Cl

o Delocalized electrons and resonance in ions and molecules

▪ Multiple bonding

o Effect on bond length and bond energies

o Rigidity in molecular structure

▪ Stereochemistry of covalently bonded molecules (OC)

o Isomers

▪ Structural isomers

▪ Stereoisomers (e.g., diastereomers, enantiomers, cis-trans isomers)

▪ Conformational isomers

o Polarization of light, specific rotation

o Absolute and relative configuration

▪ Conventions for writing R and S forms

▪ Conventions for writing E and Z forms

Liquid Phase ― Intermolecular Forces (GC)

▪ Hydrogen bonding

▪ Dipole Interactions

▪ Van der Waals’ Forces (London dispersion forces)

5C: Separation and purification methods

Separations and Purifications (OC, BC)

▪ Extraction: distribution of solute between two immiscible solvents

▪ Distillation

▪ Chromatography: basic principles involved in separation process

o Column chromatography

▪ Gas-liquid chromatography

▪ High-pressure liquid chromatography

o Paper chromatography

o Thin-layer chromatography

▪ Separation and purification of peptides and proteins (BC)

o Electrophoresis

o Quantitative analysis

o Chromatography

▪ Size-exclusion

▪ Ion-exchange

▪ Affinity

▪ Racemic mixtures, separation of enantiomers (OC)

5D: Structure, function, and reactivity of biologically relevant molecules

Nucleotides and Nucleic Acids (BC, BIO)

▪ Nucleotides and nucleosides: composition

o Sugar phosphate backbone

o Pyrimidine, purine residues

▪ Deoxyribonucleic acid: DNA; ribonucleic acid: RNA; double helix; RNA structures

▪ Chemistry (BC)

▪ Other functions (BC)

Amino Acids, Peptides, Proteins (OC, BC)

▪ Amino acids: description

o Absolute configuration at the α position

o Dipolar ions

o Classification

▪ Acidic or basic

▪ Hydrophilic or hydrophobic

o Synthesis of α-amino acids (OC)

▪ Strecker Synthesis

▪ Gabriel Synthesis

▪ Peptides and proteins: reactions

o Sulfur linkage for cysteine and cystine

o Peptide linkage: polypeptides and proteins

o Hydrolysis (BC)

▪ General principles

o Primary structure of proteins

o Secondary structure of proteins

o Tertiary structure of proteins

o Isoelectric point

The Three-Dimensional Protein Structure (BC)

▪ Conformational stability

o Hydrophobic interactions

o Solvation layer (entropy)

▪ Quaternary structure

▪ Denaturing and folding

Nonenzymatic Protein Function (BC)

▪ Binding

▪ Immune system

▪ Motor

Lipids (BC, OC)

▪ Description, types

o Storage

▪ Triacyl glycerols

▪ Free fatty acids: saponification

o Structural

▪ Phospholipids and phosphatids

▪ Sphingolipids (BC)

▪ Waxes

o Signals, cofactors

▪ Fat-soluble vitamins

▪ Steroids

▪ Prostaglandins (BC)

Carbohydrates (OC)

▪ Description

o Nomenclature and classification, common names

o Absolute configuration

o Cyclic structure and conformations of hexoses

o Epimers and anomers

▪ Hydrolysis of the glycoside linkage

▪ Keto-enol tautomerism of monosaccharides

▪ Disaccharides (BC)

▪ Polysaccharides (BC)

Aldehydes and Ketones (OC)

▪ Description

o Nomenclature

o Physical properties

▪ Important reactions

o Nucleophilic addition reactions at C=O bond

▪ Acetal, hemiacetal

▪ Imine, enamine

▪ Hydride reagents

▪ Cyanohydrin

o Oxidation of aldehydes

o Reactions at adjacent positions: enolate chemistry

▪ Keto-enol tautomerism (α-racemization)

▪ Aldol condensation, retro-aldol

▪ Kinetic vs. thermodynamic enolate

▪ General principles

o Effect of substituents on reactivity of C=O; steric hindrance

o Acidity of α-H; carbanions

Alcohols (OC)

▪ Description

o Nomenclature

o Physical properties (acidity, hydrogen bonding)

▪ Important reactions

o Oxidation

o Substitution reactions: SN1 or SN2

o Protection of alcohols

o Preparation of mesylates and tosylates

Carboxylic Acids (OC)

▪ Description

o Nomenclature

o Physical properties

▪ Important reactions

o Carboxyl group reactions

▪ Amides (and lactam), esters (and lactone), anhydride formation

▪ Reduction

▪ Decarboxylation

o Reactions at 2-position, substitution

Acid Derivatives (Anhydrides, Amides, Esters) (OC)

▪ Description

o Nomenclature

o Physical properties

▪ Important reactions

o Nucleophilic substitution

o Transesterification

o Hydrolysis of amides

▪ General principles

o Relative reactivity of acid derivatives

o Steric effects

o Electronic effects

o Strain (e.g., β-lactams)

Phenols (OC, BC)

▪ Oxidation and reduction (e.g., hydroquinones, ubiquinones): biological 2e– redox centers

Polycyclic and Heterocyclic Aromatic Compounds (OC, BC)

▪ Biological aromatic heterocycles

5E: Principles of chemical thermodynamics and kinetics

Enzymes (BC, BIO)

▪ Classification by reaction type

▪ Mechanism

o Substrates and enzyme specificity

o Active-site model

o Induced-fit model

o Cofactors, coenzymes, and vitamins

▪ Kinetics

o General (catalysis)

o Michaelis-Menten

o Cooperativity

o Effects of local conditions on enzyme activity

▪ Inhibition

▪ Regulatory enzymes

o Allosteric

o Covalently modified

Principles of Bioenergetics (BC)

▪ Bioenergetics/thermodynamics

o Free energy, Keq

o Concentration

▪ Phosphorylation/ATP

o ATP hydrolysis ΔG << 0

o ATP group transfers

▪ Biological oxidation-reduction

o Half-reactions

o Soluble electron carriers

o Flavoproteins

Energy Changes in Chemical Reactions ― Thermochemistry, Thermodynamics (GC, PHY)

▪ Thermodynamic system – state function

▪ Zeroth Law – concept of temperature

▪ First Law − conservation of energy in thermodynamic processes

▪ PV diagram: work done = area under or enclosed by curve (PHY)

▪ Second Law – concept of entropy

o Entropy as a measure of “disorder”

o Relative entropy for gas, liquid, and crystal states

▪ Measurement of heat changes (calorimetry), heat capacity, specific heat

▪ Heat transfer – conduction, convection, radiation (PHY)

▪ Endothermic, exothermic reactions (GC)

o Enthalpy, H, and standard heats of reaction and formation

o Hess’ Law of Heat Summation

▪ Bond dissociation energy as related to heats of formation (GC)

▪ Free energy: G (GC)

▪ Spontaneous reactions and ΔG (GC)

▪ Coefficient of expansion (PHY)

▪ Heat of fusion, heat of vaporization

▪ Phase diagram: pressure and temperature

Rate Processes in Chemical Reactions ― Kinetics and Equilibrium (GC)

▪ Reaction rate

▪ Dependence of reaction rate on concentration of reactants

o Rate law, rate constant

o Reaction order