OAT flashcards
OAT · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Cell theory
- All living organisms are composed of one or more cells, the cell is the basic unit of structure and function, and all cells arise from pre-existing cells.
- Mitosis vs. meiosis
- Mitosis produces two genetically identical diploid cells for growth and repair; meiosis produces four genetically distinct haploid gametes through two successive divisions.
- Hardy-Weinberg equilibrium
- Allele and genotype frequencies remain constant across generations when there is no mutation, migration, selection, or genetic drift and mating is random.
- Enzyme function
- Enzymes are biological catalysts that lower the activation energy of a reaction by stabilizing the transition state without being consumed or changing the equilibrium.
- Calvin cycle
- The light-independent stage of photosynthesis in the stroma, where RuBisCO fixes carbon dioxide into organic molecules using ATP and NADPH from the light reactions.
- Ideal gas law
- PV = nRT relates pressure, volume, moles, and absolute temperature; R equals 0.0821 L·atm/(mol·K), and one mole occupies 22.4 L at STP.
- Molarity
- Molarity is the number of moles of solute per liter of solution; dilution obeys M₁V₁ = M₂V₂ because the moles of solute remain constant.
- pH scale
- pH equals the negative logarithm of hydrogen ion concentration; at 25 °C, pH plus pOH equals 14, and a pH below 7 indicates an acidic solution.
- Le Chatelier's principle
- When a system at equilibrium is disturbed by a change in concentration, pressure, or temperature, the system shifts to partially counteract that change.
- Oxidation and reduction
- Oxidation is the loss of electrons and reduction is the gain of electrons; the reducing agent is oxidized and the oxidizing agent is reduced in a redox reaction.
- Quantum numbers
- The principal quantum number n gives the shell, l gives the subshell, ml gives the orbital orientation, and ms gives spin; no two electrons share all four.
- Periodic trends
- Atomic radius decreases across a period and increases down a group, while electronegativity and ionization energy generally increase across a period and decrease down a group.
- Hybridization
- Four electron domains give sp³ tetrahedral geometry near 109.5°, three give sp² trigonal planar near 120°, and two give sp linear at 180°.
- SN1 vs. SN2
- SN1 is a two-step reaction through a carbocation, favored by tertiary substrates and polar protic solvents; SN2 is a one-step backside attack favored by primary substrates.
- Markovnikov's rule
- In addition of HX to an alkene, the hydrogen adds to the carbon with more hydrogens, placing the halogen on the more substituted carbon.
- Alcohol oxidation
- Primary alcohols oxidize to aldehydes and then carboxylic acids, secondary alcohols oxidize to ketones, and tertiary alcohols resist oxidation under mild conditions.
- Chirality
- A carbon bonded to four different groups is a stereocenter; a molecule with one stereocenter is chiral, and its two enantiomers rotate plane-polarized light in opposite directions.
- Hückel's rule
- A planar, cyclic, fully conjugated system with 4n + 2 π electrons is aromatic, while one with 4n π electrons is antiaromatic; nonconjugated rings are nonaromatic.
- Carboxylic acid derivatives
- Reactivity decreases in the order acid chloride, anhydride, ester, amide; hydrolysis of any of these produces the parent carboxylic acid.
- Main idea questions
- These ask what the passage is primarily about; the correct answer summarizes the whole passage rather than a single supporting detail or example.
- Inference questions
- These ask what can reasonably be concluded from the passage; the correct answer follows logically from stated information without adding outside assumptions.
- Vocabulary-in-context
- These questions ask for the meaning of a word as it is used in the passage; surrounding sentences, not the most common dictionary definition, determine the answer.
- EXCEPT and NOT questions
- These ask which choice is not supported by the passage; evaluate each choice against the text and eliminate the three that are directly supported.
- Author's tone
- Tone questions ask about the author's attitude, which is inferred from word choice and emphasis; extreme answer choices are often incorrect.
- Kinematics equations
- For constant acceleration: v = v₀ + at, Δx = v₀t + ½at², and v² = v₀² + 2aΔx; these do not apply when acceleration changes.
- Newton's second law
- The net force on an object equals its mass times its acceleration; weight equals mg, and normal force equals mg only when no other vertical forces act.
- Conservation of energy
- When only conservative forces do work, the sum of kinetic and potential energy stays constant; friction converts mechanical energy into thermal energy.
- Ohm's law and power
- V = IR relates voltage, current, and resistance; electrical power is P = IV = I²R = V²/R, and series resistors add while parallel resistors combine reciprocally.
- Snell's law
- n₁ sin θ₁ = n₂ sin θ₂ describes refraction; light bends toward the normal when entering a medium with a higher index of refraction.
- Percent change
- Percent change equals (new − old) divided by old, times 100; a 20% increase followed by a 20% decrease produces a net 4% decrease.
- Combinations and permutations
- nCr = n!/[r!(n−r)!] counts unordered selections of r items from n, while nPr = n!/(n−r)! counts ordered arrangements of r items.
- Quadratic formula
- For ax² + bx + c = 0, x = [−b ± √(b² − 4ac)]/(2a); the discriminant b² − 4ac determines whether the roots are real, repeated, or complex.