More to this section coming soon!
This section tests the application of chemical and physical concepts to complex passages that require knowledge of foundational concepts, as well as an ability to read complex scientific literature. The content for this section includes:
25% Biochemistry, 5% Biology, 30% Chemistry, 15% Organic Chemistry, and 25% Physics.
To do well in this section make sure to understand all of the concepts listed below as well as spend at least half of the time preparing for this section by completing practice passages and tests. For the official content listing look at the AAMC official exam content. All of the content covered in the section is listed below. One thing to keep in mind, however, is that it is not necessary to know every single concept listed below to do well on the MCAT. It is more important to have a strong grasp of the main concepts and be able to apply them. This is a list of every possible topic that may be covered in the exam.
Motion, Forces, Equilibrium, Work, Energy
Translational Motion (PHY)
- Units and dimensions
- There are four different dimensions. The first is magnitude, the second is length, the third creates 3-dimensional space (like an xyz plane) and the fourth is time.
- Have a general understanding of unit prefixes (kilo=1000, milli=.001, etc…) and of common units such as meter, second, joule, Newton, kg.
- Vectors, components
- Vectors possess both magnitude and direction. They can be added, or subtracted.
- Vectors can also be broken down into horizontal and vertical components. Use trigonometry to find the vertical and horizontal components.
- Vector addition
- Vectors can be added by first breaking them down into vertical and horizontal components, then adding the vertical components together and adding the horizontal components together to form a new vector.
- Speed, velocity (average and instantaneous)
- Speed is a scalar value, meaning it is just a magnitude. Velocity is a vector, and involves both a magnitude (in this case speed) and a direction. Average velocity is velocity over a period of time, and instantaneous velocity is velocity at a particular point in time.
- Acceleration is the rate at which velocity changes. If the velocity changes from 5m/s to 1m/s over a period of 2 seconds, the acceleration is -4m/(s^2). What’s most important is to understand the relationship between distance, displacement, speed, velocity, acceleration, and time.
- Newton’s First Law, inertia
- An objects motion will not change unless acted upon by an external force
- Newton’s Second Law (F = ma)
- Force equals mass times acceleration. Eat, sleep, and dream this.
- Newton’s Third Law
- For every force there is an equal and opposite force being exerted back. If you push on the wall with 5N, the wall is pushing on your hands in the opposite direction with 5N of force.
- Friction, static and kinetic
- Force of friction = coefficient of friction * normal force
- Each material has both a static and kinetic coefficient of friction. The static coefficient of friction is used when the object whose motion is being measured is not moving. The kinetic coefficient of friction is used when the object is moving along the surface of the material with the coefficient of friction. The kinetic coefficient of friction is lower than the static coefficient of friction.
- Center of mass
- The center of mass can be thought of as the “average” location of mass, or the point where the mass is concentrated. If you know the center of mass, an object can be treated as a point mass, where the shape of the object does not have to be taken into account to calculate its trajectory.
- Vector analysis of forces acting on a point object
- If there are multiple forces acting on an object, the vectors of those forces can be added up. The vector that is the sum of all of the forces acting on an object is the total force on that object, and can be used to analyze that objects acceleration with the equation “F=ma”.
- An object is in equilibrium if the sum of all forces acting on that object equals 0.
- Torques, lever arms
- T = F * r * sin(theta)
- T is torque, F is force, and r is radius length between the force and the center of mass of the object. Theta is the angle between the radius vector and the force vector.
- Torque is proportional to the angular acceleration of an object.
- Lever arm is the perpendicular distance from the axis of rotation to the force applied. Learn more.
- Work done by a constant force: W = Fd cosθ
- Work is done to an object when the force causes the object to move a certain distance. For example, work is done by gravity when an object is pulled down.
- Work is measured in Joules, which are Newton meters.
- Mechanical advantage
- Mechanical advantage is a measure of the ratio of force applied to a tool by the force on a object by the tool. Great examples of tools that provide mechanical advantage are levers, gears, and pulleys.
- Work Kinetic Energy Theorem
- Work equals the change in kinetic energy.
- This theorem makes sense because if you perform positive work on an object, you increase its kinetic energy. And if you perform negative work on an object, you slow it down and decrease its kinetic energy.
- Conservative forces
- Conservative forces are those in that the work done on the object is independent of the path taken by that object. Examples of conservative forces are gravity, electric force, and spring forces. An example of a non-conservative force is friction.
Energy of Point Object Systems (PHY)
- Kinetic Energy: KE = ½ m(v22)
- Kinetic energy is the measure of energy within the motion of an object. Joules are the units for kinetic energy.
- Potential Energy
- Potential energy is the energy an object has stored as a result of its position. For example, an object held high off the ground has a lot of gravitational potential energy.
- PE = mgh (gravitational, local)
- PE = ½ kx2 (spring)
- Conservation of energy
- The total energy of an isolated system does not change.
- Power, units
- Power is the rate of work per second, and also the rate of energy consumed per second.
Periodic Motion (PHY)
- Amplitude, frequency, phase
- Periodic motion is motion that is repeating, such as the rocking of a chair or swinging of a pendulum. It can be measured in sine and cosine waves.
- Amplitude is the maximum displacement from equilibrium.
- Frequency is the number of full cycles per second, measured in Hertz (Hz).
- Two waves are in-phase when they reach their maximum displacement at the same time. Waves are out-of-phase when they are not 0 or 360 degrees apart. Out-of-phase waves exhibit interference and work against each other.
- Transverse and longitudinal waves: wavelength and propagation speed
- Transverse waves have displacement perpendicular to the direction of motion. An example of this is light.
- Longitudinal waves have displacement parallel to the direction of motion, such as sound.
- Wavelength is the distance between peaks.
- v = fλ
- Wave velocity is determined by the medium the wave travels through. Waves with higher frequencies will have lower wavelengths, and waves with lower frequencies will have higher wavelengths.
Fluids, Gas Movement and Exchange
- Density, specific gravity
- Density = mass/volume.
- The density of water is 1 g/mL, which is 1kg/L.
- Specific gravity is density divided by the density of water.
- Buoyancy, Archimedes’ Principle
- Arhcimedies’ principle is: Buoyancy force = force of the weight displaced by the object. Learn more.
- Force of Buoyancy = (density of fluid) x (volume of submerged object) x gravity.
- Hydrostatic pressure
- The pressure exerted by a gravity within a fluid at a certain point. The deeper the point, the higher the hydrostatic pressure.
- Pascal’s Law
- Hydrostatic pressure = ρgh, where ρ is fluid density, g is gravity, and h is depth. Understand that pressure is proportional to depth.
- Pascal’s law: external pressure exerted on a liquid in a container is distributed throughout the fluid.
- Viscosity: fluid resistance to flow.
- Poiseuille flow: When a slightly viscous fluid flows through a tube, such as blood through arteries, the fluid in the center of the tube flows faster than fluid along the side of the tube. This flow is due to the increased friction along the sides of the tube.
- Continuity equation (A∙v = constant)
- Continuity equation: the volume flow rate through a tube is constant. As the area of the tube decreases, the velocity of the fluid increases and vice versa. This concept is very important to understand!
- Concept of turbulence at high velocities
- Fluid flow at high velocities causes turbulence, which causes eddies, or swirls, in the fluid. At low velocities there is very little turbulence.
- Surface tension
- Surface tension occurs due to the attraction between molecules of a fluid. Water has a high surface tension.
- Bernoulli’s equation
- P + ½ρv2 + ρgh = constant throughout the tube
- Describes the relationship between fluid velocity, pressure (and area of the tube because P=F/A), height, and fluid density.
- Venturi effect, pitot tube
- Venturi effect: As the fluid flows through a constricted area of a tube, there is a reduction in fluid pressure.
- An right-angled tube that measures pressure by comparing the fluid pressure with static pressure.
- Can be explained by the Bernoulli equation.
Circulatory System (BIO)
- Arterial and venous systems; pressure and flow characteristics
- This is an applied understanding of the continuity equation. There is a much higher cross sectional area across all of the capillaries combined than of all of the arteries. Because of this, the blood pressure within arteries is much higher than in capillaries.
- It is important to understand the pressure-volume loop.
Gas Phase (GC, PHY)
- Absolute temperature, (K) Kelvin Scale
- The SI unit for temperature is the Kelvin scale. K = ˚C + 273.15.
- Absolute zero, at 0K, is the coldest possible temperature. There is no intermolecular motion at absolute zero.
- Pressure, simple mercury barometer
- Pressure = Force/Area
- The mercury barometer determines the atmospheric pressure by the fluid density and height difference of fluid.
- Molar volume at STP
- The volume of one mole of any gas at 0°C and 1 atm is 22.4 L. Memorize this!!
- Ideal gas
- An ideal gas is a theoretical gas that only is affected by elastic collisions. On the MCAT, unless stated otherwise gases will be treated as ideal to simplify calculations.
- Ideal Gas Law: PV = nRT
- P = pressure in Pa, V = volume in L, n = number of moles, R = gas constant, T = temperature in Kelvins
- Boyle’s Law: PV = constant
- Charles’ Law: V/T = constant
- Avogadro’s Law: V/n = constant
- Kinetic Molecular Theory of Gases
- There are 5 postulates in this theory. It is important to understand the general idea, but don’t get bogged down in specific details or advanced physics problems. The most important conclusion of the theory is that the average kinetic energy of a collection of gas particles depends only on the temperature of the gas.
- Heat capacity is the amount of heat that is required to raise the temperature of an object one degree and is measured in J/K.
- The Boltzmann Constant (k or kB), is the relationship between absolute temperature and kinetic energy in each molecule of an ideal gas. kB=R/NA, where R is the gas constant and NA is the Avogadro Constant. Learn more.
- Deviation of real gas behavior from Ideal Gas Law
- At low temperatures and high pressures, real gas behavior deviates from the ideal gas law because the molecular volume and intermolecular attractions significantly affect gas behavior.
- The van der Waals equation is a quantitative way to measure deviation of real gases from the ideal gas law. Have an understanding for how this equation works, but you do not need to have it memorized.
- Partial pressure, mole fraction
- Partial pressure: the pressure exerted by one particular gas in a mixture of gases. If 50% of the moles of gas in a mixture are gas A and the container has a pressure of 100Pa, gas A has a partial pressure of 50Pa.
- Mole fraction: the number of moles of a particular gas divided by the total number of moles of gas in a container.
- Dalton’s Law
- The total mixture of gas is equal to the sum of the partial pressures of each individual gas.
Electrochemistry and Electrical Circuits
- Charge, conductors, charge conservation
- Charges are positive, negative, or neutral. Like charges repel and opposite charges attract. Charge is measured in Coulombs
- Conductors are materials that charges can travel through well.
- Charge conservation: Charges cannot be created or destroyed. If a positive charge is induced in one place, a negative charge is induced elsewhere.
- Insulators are materials that charges cannot travel through very well.
- Coulomb’s Law
- F = kq1q2/r2.
- F= Electrostatic force, k = proportionality constant, q1 and q2 = charge, r= radius.
- Electric field E
- Electric field is a measure of the electric force per unit of charge.
- Understand electric field lines and their patterns when two object with different charges interact.
- Electrostatic energy, electric potential at a point in space
- Electrostatic energy (also called electric potential energy) is stored up energy due to the positioning of charges. Electrostatic energy as well as electric field lines are complicated but important to understand for the MCAT.
- Electric potential is different than electric potential energy. Electric potential is the amount of electrostatic potential energy per unit charge. It is important to understand the difference between electric potential energy and electric potential.
Circuit Elements (PHY)
- Current, sign conventions, units
- Current is the rate of charge flow through a cross section of wire.
- I = ΔQ/Δt (I = Current, Q = charge, t = time.)
- Voltage, electromotive force
- Voltage: A difference in electric potential. Measured in volts.
- Electromotive force: the voltage generated by an electrical source in a circuit, such as a battery.
- Voltage and electromotive force are slightly different concepts. Electromotive force is the voltage before the resistors are included in the circuit to lower the overall voltage.
- Resistance is a reluctancy of charge to flow through a material. Resistance can be understood in terms of Ohm’s law.
- Ohm’s Law: I = V/R
- I = current, V = voltage, R = resistance
- This equation can be used to understand the total voltage of a circuit, the resistance of individual resistors, as well as the current through various sections of wire.
- Resistors in series
- Resistors in series are arranged in a chain. Rtotal = R1 + R2 + …
- Resistors in parallel
- Resistors connected in parallel branch out from a single point and allow multiple paths for current to flow. The equation for resistors in parallel is a bit more complicated. 1/Rtotal = 1/R1 + 1/R2 + …
- Resistivity: ρ = R•A / L
- Resistivity is a property of a particular substance. It can be calculated by dividing the product of the resistance and the area of the wire by the length of the wire. For example, the resistivity of copper is 1.7.
- Capacitance is the ability of an object to store electrical charge.
- Capacitance= Charge/Voltage
- Parallel plate capacitor
- A parallel plate capicitor stores charge by making one of the plates positive and the other plate negative. These two plates are made of conductive material and are separated by an insulator.
- Energy of charged capacitor
- Capacitance = charge/voltage
- Energy stored on capacitor=(1/2)(charge)(voltage)
- Capacitors in series
- For capacitors in series, 1/Ctotal = 1/C1 + 1/C2 + …
- Capacitors in parallel
- For capacitors in parallel, Ctotal = C1 + C2 + … This is like resistors in series!
- Dielectrics are materials that do not conduct electricity well. They are put between two plates of a capacitor to increase capacitance by either increasing Q (charge) or decreasing V (voltage).
- When charge is applied to a capacitor, one of the plates becomes positive and one becomes negative. With a dielectric substance present in between the two plates, The molecules within the dielectric substance become polarized, creating an electric field that opposese the electric field of the opposite charges on the plates. This decreases the overall electric field between the plates. Because the capacitance is inversely proportional to the electric field, with a dielectric material in between the plates increases the capacitance.
- Conductivity is the opposite of resistance, and allows charges to travel easily.
- Metallic conductivity occurs because within metals, electrons can easily leave the atoms and travel throughout the material. Think of metallic conductivity like a sea of electrons.
- Ions dissolved in a solution cause that solution to be conductive. The more ions dissolved in a solution, the more conductivity of the solution. For example, water with no ions in it will have no conductivity.
- Voltmeter: This meter is connected in parallel to a circuit and measures the voltage between the two points it is connected to.
- Ammeter: An instrument that measures the current of a circuit and is connected in series to the circuit.
- Magnetic field
- Magnetic field (B) exists as a result of a moving charge. The magnetic field is defined as force on moving charges.
- Motion of charged particles in magnetic fields; Lorentz force
- Lorentz force= qE + qvB. In this equation, E(electric force) is a vector, v (velocity) is a vector, and B (magnetic force) is a vector. For this equation, use the right hand rule to determine the direction of force.
- Electrolytic cell
- An electrolytic cell consists of electrodes connected by a battery and inserted into an electrolytic solution. The voltage from the battery is used to drive an oxidation-reduction reaction to occur between the metal in the cathode and in the anode with ions in the electrolytic solution.
- There are two types of electrodes. The cathode is the electrode that gets reduced, the anode is the electrode that gets oxidized.
- Electrolysis is the process of using a voltage to drive an oxidation-reduction reaction when it would not occur spontaneously.
- Anode, cathode
- There are two types of electrodes. The cathode is the electrode that gets reduced, the anode is the electrode that gets oxidized.
- The anode releases electrons, the cathode accepts electrons.
- A liquid with ions is an electrolyte. Electrolytes are liquids that conduct electricity.
- Faraday’s Law relating amount of elements deposited (or gas liberated) at an electrode to current
- Connecting Faraday’s law to electrolytic cells allows us to calculate the amount of moles of electrons exchanged based off of the amount of current. The important thing from Faraday’s law here is that Faraday’s constant : 1 mole of electrons has 96484 C. In a problem, if they gave you the charge, you would be able to calculate how many moles of electrons there are.
- Electron flow; oxidation, and reduction at the electrodes
- Electrons leave the anode because the anode is oxidized. Electrons enter the cathode because the cathode is reduced.
- Galvanic or Voltaic cells
- Galvanic cells are the same thing as voltaic cells. Glavanic cells are similar to electrolytic cells, except instead of a battery connecting the two electrodes, a resistor is connecting them. This resistor can be an object that is being powered, such as a lightbulb. Galvanic cells do not need a battery because these cells have different solute concentrations than electrolytic cells and thus undergo a spontaneous oxidation-reduction reaction.
- Half reactions describe either an oxidation reaction or a reduction reaction. When looking at and balancing oxidation-reduction reactions the best thing to do is break the single reaction down into half reactions. An example of a half reaction is: Na+ + e– → Na
- Reduction potentials; cell potential
- Reduction potential is the volage (potential change) that occurs with a particular half reaction. The oxidation potential for a reaction is the opposite of the reduction potential. Cell potential is the sum of reduction potential + oxidation potential. In a galvanic cell, the cell potential is the voltage generated by the reduction-oxidation reactions that occur within that particular cell.
- Direction of electron flow
- Overall electron flow is from the anode towards the cathode through the resistor (or for an electrolytic cell through the battery).
- Concentration cell
- A concentration cell is a galvanic cell in which boths halves of the cell are the same electrodes and solutes. The only thing that differs between the sides is the solute concentration.
- Electromotive force, Voltage
- Batteries have a large voltage difference that drives electrons to move, creating a current. The electromotive force describes the force that causes electrons to move as a result of the voltage difference.
- Lead-storage batteries
- The electrodes of lead-storage batteries is a grid of lead electrodes. The anion is lead (Pb) and the cation is lead dioxide (PbO2). The electrolyte is sulfuric acid.
- Nickel-cadmium batteries
- Nickel oxide-hydroxide (NiO(OH)) is used as cathodes. Cadmium (Cd) plates are used as anodes. Potassium is used as the electrolyte.
Specialized Cell – Nerve Cell (BIO)
- Myelin sheath, Schwann cells, insulation of axon
- Look at the biology and biochemistry section to understand what action potentials, myelin sheath, and nodes of ranvier are and how they function. Basically, myelin sheath insulates the axon of the neuron, allowing charges to “jump” from node to node. Nodes of Ranvier are the spaces in between the myelin sheath.
- Nodes of Ranvier: propagation of nerve impulse along axon
- The nerve impulse travels faster when myelin is present because it is able to move from node to node very quickly. The reason the action potential is able to move from one node to the next is that the influx of positive ions within a particular node is so big that some of the positive ions are pushed to the next node within the axon. These positive ions that were pushed to the next node then depolarize that node, causing propagation of the axon potential.
Light and Sound
- Production of sound
- Sound is produced by causing vibrations in a particular medium. For example, the vibration of a human’s vocal cord causes the medium, in this case air, to vibrate with longitudinal waves. There is no sound in space because there is no air in space to vibrate.
- Relative speed of sound in solids, liquids, and gases
- The medium through which a sound travels affects its speed. The wavelenth and frequency of a sound are constant. Solids are much more dense than gases and allow sounds to travel much quicker through them. For example, waves of sound within a vibrating metal tuning fork will travel much faster than waves of sound through the air. Sound in solids travels faster than in liquids, which travels faster than in gases.
- Intensity of sound, decibel units, log scale
- Intensity, measured in decibels, is based on a logarithmic scale. This is very important to understand for the MCAT. This means that a sound with 40 decibels of intensity has 1000 times greater intensity than a sound measured with 10 decibels of intensity. The reason the decibel scale is logarithmic is because it was created based on human perception.
- Attenuation describes the process of sounds getting quieter as they travel. Sounds lose intensity as they move through a medium. This occurs as energy from the sound waves disspates throughout the medium.
- Doppler Effect: moving sound source or observer, reflection of sound from a moving object
- The dopper effect describes how the observed frequency of sound waves can be different from the frequency of waves emanated from a source. This happens when the source is in motion relative to the observer.
- Pitch is the perception of the frequency of sound. Sounds with a higher frequency (smaller wavelength) have higher pitch.
- Resonance in pipes and strings
- Every single material has a natural frequency. This is the frequency that a material will naturally vibrate at if not acted upon by a force. When a sound vibration in a pipe, or a vibration in a string has the same frequency as the pipe or string’s natural frequency, this is called resonance. With resonance, the amplitude of vibration is increased.
- In these problems, the frequency can be found by using the formula: f = v/λ. Remember, with this, the velocity of a wave is determined by the medium through which it travels.
- Nodes are where waves overlap in opposite directions and cancel each other out so there is no movement. Antinodes occur when waves superimpose to form the greatest amplitude. These are the opposite of nodes.
- It is important to understand the formulas that describe the behavior of waves. For strings and pipes with open ends (antinodes), L = n/2λ. For strings and pipes with a node for one end, the formula is L = (2n-1)/4λ.
- This will likely be tested on the MCAT. An ultrasound device emits high frequency soundwaves which emenate from the device. As the waves pass through an interface between two different types of tissue within the human body, some of them are reflected back. Because of this, an image is formed. To understand this concept fully it is important to understand the doppler effect and how an ultrasound would detect the waves reflected from an object moving towards and away from it.
- Shock waves
- Shock waves are a particular case of the doppler effect. With shock waves, the source is moving just as fast as the wave. Think of an airplane breaking the sound barrier. In this situation, for a moment the airplane is flying at exactly the same speed as soundwaves travel. Because of this, the soundwaves traveling in the same direction as the plane do not actually move away from the plane. Thus, as more sound waves are produced they all superimpose upon one another and cause a loud “boom” to be heard.
Light, Electromagnetic Radiation (PHY)
- Concept of Interference; Young Double-slit Experiment
- Destructive nterference occurs when two waves overlap but they have completely opposite phases so they cancel eachother out. When this occurs the amplitude is zero. Constructive interference occurs when two waves superimpose upon each other and create a wave with higher amplitude. As light waves travel through two very thin slits close to eachother, the waves diffract around the slits in half-circle patterns. These waves interfere with each other to cancel each other out in some places, and constructively interfere in others to cause a striped pattern.
- Thin films, diffraction grating, single-slit diffraction
- Thin film interference can be complicated so its important to just undertand the general idea of what is going on. With a thin film, there are interfaces on both sides of the thin film. It is at these interfaces that some waves pass through and others are reflected back. Because the waves travel slightly different lengths (depending on whether or not they were reflected or passed through the first and second interface) they can overlap each other and constructively or destructively interfere. d sin ɵ = mλ is a helpful equation, where d is the distance between the slits, ɵ is the angle between the diffracted light and a perpendicular line coming from the slit, m is the order number (0 is in the center by the two slits) and λ is the wavelength of light.
- A large number of parallel slits are closely spaced together to form a diffraction grating, similar to the slits in the double slit experiment. A diffraction grating is used to find the wavelength of different colors contained in a light beam.
- With single slit interference the lightwaves projected onto a screen arrive from different parts within the slit, which is wider than the slit used in double slit interference. Because waves arrive from different parts in the slit, they may travel slightly different length to get to the screen, so they will be out of phase at different parts of the screen.
- Other diffraction phenomena, X-ray diffraction
- X-ray diffraction is passing x-ray waves through a crystal and seeing how they diffract to learn about the structure of the crystal.
- Polarization of light: linear and circular
- Light is naturally unpolarized, meaning that the waves are not rotated in any particular direction.
- Light becomes polarized as it passes through a polaroid filter that only lets light waves of a certain orientation pass through.
- Properties of electromagnetic radiation
- Electromagnetic radiation is energy released by certain electromagnetic processes. Some examples of electromagnetic radiation are light, microwaves, radio waves, and x-rays.
- Velocity equals constant c, in vacuo
- In a vaccum, all electromagnetic waves, including light, travel at speed c, which is a constant of 3 * 108.
- Electromagnetic radiation consists of perpendicularly oscillating electric and magnetic fields; direction of propagation is perpendicular to both
- Electromagnetic waves are made of both waves of waves of electric variation and waves of magnetic variation. These variations travel together to form electromagnetic waves.
- Classification of electromagnetic spectrum, photon energy E = hf
- It is important to have an understanding that ultraviolet, x-rays, and gamma rays have a much smaller wavelength than visible light, and infared light and microwaves have a larger wavelengths. Have a general idea of the order of the spectrum
- Though we have looked at light as made up of waves, it also has some of the properties of particles. The smallest particle of light is called a photon. The energy of a photon equals planks constant multiplied by the frequency of the wave of light that the photon is a part of (Ephoton = hf).
- Visual spectrum, color
- Red has the longest wavelengths of the visual spectrum with ~700nm, and blue has a wavelength of ~450nm.
Molecular Structure and Absorption Spectra (OC)
- Infrared region
- Absorption in the infrared region is used via infrared spectroscopy (IR spectroscopy) to identify what types of bonds are within a particular molecule. Bonds between different atoms in a molecule cause different wavelengths to be absorbed, allowing scientists to identify what molecule they are working with based off of the infrared abosorption spectra from IR spectroscopy.
- Intramolecular vibrations and rotations
- IR spectroscoscopy uses infared radiation to identify which bonds are present within a molecule. Each bond between molecules vibrates at a particular frequency, like two balls connected by a spring. Each of these bonds absorbs a particular wavelength of infrared light. On an IR spectrum, there will be less transmittance (light shining through) at a certain wavenumber if a bond exists that absorbs that wavelength. For example, C=O double bonds form absorb a strong amount of infrared light at 1700. Because of this, you can tell that there are C=O bonds in the molecule if there is a peak at 1700.
- Recognizing common characteristic group absorptions, fingerprint region
- Visible region (GC)
- Absorption in visible region gives complementary color
- Effect of structural changes on absorption (e.g.,
- Ultraviolet region
- π-Electron and non-bonding electron transitions
- Conjugated systems
- NMR spectroscopy
- Protons in a magnetic field; equivalent protons
- Spin-spin splitting
Geometrical Optics (PHY)
- Reflection from plane surface: angle of incidence equals angle
- Refraction, refractive index n; Snell’s law: n1 sin θ1 = n2
- Dispersion, change of index of refraction with wavelength
- Conditions for total internal reflection
- Spherical mirrors
- Center of curvature
- Focal length
- Real and virtual images
- Thin lenses
- Converging and diverging lenses
- Use of formula 1/p + 1/q = 1/f, with sign conventions
- Lens strength, diopters
- Combination of lenses
- Lens aberration
- Optical Instruments, including the hum
Atomic Structure and Behavior
Atomic Nucleus (PHY, GC)
- Atomic number, atomic weight
- Neutrons, protons, isotopes
- Nuclear forces, binding energy
- Radioactive decay
- α, β, γ decay
- Half-life, exponential decay, semi-log plots
- Mass spectrometer
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 non-metals
- Oxygen group
The Periodic Table – Variations of Chemical Properties with
Group and Row (GC)
- Valence electrons
- First and second ionization energy
- Prediction from electronic structure for elements in
different groups or rows
- Electron affinity
- Variation with group and row
- Comparative values for some representative elements and
- Electron shells and the sizes of atoms
- Electron shells and the sizes of ions
- Molecular weight
- Empirical versus 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
- Common oxidizing and reducing agents
- Disproportionation reactions
- Description of reactions by chemical equations
- Conventions for writing chemical equations
- Balancing equations, including redox equations
- Limiting reactants
- Theoretical yields
Water and its Solutions
Acid/Base Equilibria (GC, BC)
- Brønsted–Lowry definition of acid, base
- Ionization of water
- Kw, its approximate value (Kw = [H+][OH–] = 10–14 at 25°C, 1
- 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)
- Dissociation of weak acids and bases with or without added salt
- Hydrolysis of salts of weak acids or bases
- Calculation of pH of solutions of salts of weak acids or
- Equilibrium constants Ka and Kb: pKa, pKb
- Definition and concepts (common buffer systems)
- Influence on titration curves
Ions in Solutions (GC, BC)
- Anion, cation: common names, formulas and charges for familiar ions (e.g., NH4+ ammonium, PO4 3– phosphate, SO4 2– sulfate)
- Hydration, the hydronium ion
- Units of concentration (e.g., molarity)
- Solubility product constant; the equilibrium expression Ksp
- Common-ion effect, its use in laboratory separations
- Complex ion formation
- Complex ions and solubility
- Solubility and pH
- Interpretation of the titration curves
- Redox titration
Covalent Bond (GC)
- Lewis Electron Dot formulas
- Resonance structures
- Formal charge
- Lewis acids and bases
- Partial ionic character
- Role of electronegativity in determining charge distribution
- Dipole Moment
- σ and π bonds
- Hybrid orbitals: sp3, sp2, sp and respective geometries
- Valence shell electron pair repulsion and the prediction of shapes of molecules (e.g.,
- NH3, H2O, CO2)
- Structural formulas for molecules involving H, C, N, O, F, S, P, Si, Cl
- Delocalized electrons and resonance in ions and molecules
- Multiple bonding
- Effect on bond length and bond energies
- Rigidity in molecular structure
- Stereochemistry of covalently bonded molecules (OC)
- Structural isomers
- Stereoisomers (e.g., diastereomers, enantiomers, cis/trans isomers)
- Conformational isomers
- Polarization of light, specific rotation
- 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)
Separation and Purification Methods
Separations and Purifications (OC, BC)
- Extraction: distribution of solute between two immiscible
- Chromatography: Basic principles involved in separation
- Column chromatography
- Gas-liquid chromatography
- High pressure liquid chromatography
- Paper chromatography
- Thin-layer chromatography
- Separation and purification of peptides and proteins (BC)
- Quantitative analysis
- Racemic mixtures, separation of enantiomers (OC)
Structure and Function of Biologically-Relevant Molecules
Nucleotides and Nucleic Acids (BC, BIO)
- Nucleotides and nucleosides: composition
- Sugar phosphate backbone
- Pyrimidine, purine residues
- Deoxyribonucleic acid: DNA; double helix
- Chemistry (BC)
- Other functions (BC)
Amino Acids, Peptides, Proteins (OC, BC)
- Amino acids: description
- Absolute configuration at the α position
- Dipolar ions
- Acidic or basic
- Hydrophilic or hydrophobic
- Synthesis of α-amino acids (OC)
- Strecker Synthesis
- Gabriel Synthesis
- Peptides and proteins: reactions
- Sulfur linkage for cysteine and cystine
- Peptide linkage: polypeptides and proteins
- Hydrolysis (BC)
- General Principles
- Primary structure of proteins
- Secondary structure of proteins
- Tertiary structure of proteins
- Isoelectric point
The Three-Dimensional Protein Structure (BC)
- Conformational stability
- Hydrophobic interactions
- Solvation layer (entropy)
- Quaternary structure
- Denaturing and Folding
Non-Enzymatic Protein Function (BC)
- Immune system
Lipids (BC, OC)
- Description, Types
- Triacyl glycerols
- Free fatty acids: saponification
- Phospholipids and phosphatids
- Sphingolipids (BC)
- Fat-soluble vitamins
- Prostaglandins (BC)
- Nomenclature and classification, common names
- Absolute configuration
- Cyclic structure and conformations of hexoses
- Epimers and anomers
- Hydrolysis of the glycoside linkage
- Keto-enol tautomerism of monosaccharides
- Disaccharides (BC)
- Polysaccharides (BC)
Aldehydes and Ketones (OC)
- Physical properties
- Important reactions
- Nucleophilic addition reactions at C=O bond
- Acetal, hemiacetal
- Imine, enamine
- Hydride reagents
- Oxidation of aldehydes
- Reactions at adjacent positions: enolate chemistry
- Keto-enol tautomerism (α-racemization)
- Aldol condensation, retro-aldol
- Kinetic versus thermodynamic enolate
- General principles
- Effect of substituents on reactivity of C=O; steric hindrance
- Acidity of α-H; carbanions
- Physical properties (acidity, hydrogen bonding)
- Important reactions
- Substitution reactions: SN1 or SN2
- Protection of alcohols
- Preparation of mesylates and tosylates
Carboxylic Acids (OC)
- Physical properties
- Important reactions
- Carboxyl group reactions
- Amides (and lactam), esters (and lactone), anhydride
- Reactions at 2-position, substitution
Acid Derivatives (Anhydrides, Amides, Esters) (OC)
- Physical properties
- Important reactions
- Nucleophilic substitution
- Hydrolysis of amides
- General principles
- Relative reactivity of acid derivatives
- Steric effects
- Electronic effects
- 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
Thermodynamics and Kinetics
Enzymes (BC, BIO)
- Classification by reaction type
- Substrates and enzyme specificity
- Active site model
- Induced-fit model
- Cofactors, coenzymes, and vitamins
- General (catalysis)
- Effects of local conditions on enzyme activity
- Regulatory enzymes
- Covalently modified
Principles of Bioenergetics (BC)
- Free energy/Keq
- ATP hydrolysis ΔG << 0
- ATP group transfers
- Biological oxidation–reduction
- Soluble electron carriers
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
- Entropy as a measure of “disorder”
- Relative entropy for gas, liquid, and crystal states
- Measurement of heat changes (calorimetry), heat capacity,
- Heat transfer – conduction, convection, radiation (PHY)
- Endothermic/exothermic reactions (GC)
- Enthalpy, H, and standard heats of reaction and formation
- 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
- Reaction rate
- Dependence of reaction rate on concentration of reactants
- Rate law, rate constant
- Reaction order
- Rate-determining step
- Dependence of reaction rate upon temperature
- Activation energy
- Activated complex or transition state
- Interpretation of energy profiles showing energies of reactants, products, activation energy, and ΔH for the reaction
- Use of the Arrhenius Equation
- Kinetic control versus thermodynamic control of a reaction
- Equilibrium in reversible chemical reactions
- Law of Mass Action
- Equilibrium Constant
- Application of Le Châtelier’s Principle
- Relationship of the equilibrium constant and ΔG°