MDCAT flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Enzyme active site
- The specific pocket on an enzyme where substrate binds. Its complementary shape lowers activation energy, and changes in temperature or pH can alter it.
- Semi-conservative replication
- DNA replication in which each new double helix contains one original parental strand and one newly synthesized strand, following complementary base pairing.
- Crossing over
- Exchange of genetic segments between homologous chromosomes during prophase I of meiosis, which increases genetic variation in the resulting haploid cells.
- Resting membrane potential
- The electrical potential across a neuron membrane at rest, about −70 mV, maintained by ion pumps and leak channels with the inside negative.
- Hemoglobin function
- An iron-containing protein in red blood cells that binds oxygen in the lungs and releases it in tissues, helped by cooperative binding.
- Calvin cycle
- The light-independent stage of photosynthesis in the chloroplast stroma, where RuBisCO fixes carbon dioxide using ATP and NADPH to make G3P.
- Monohybrid cross ratio
- A cross between two heterozygotes for one gene yields a 3:1 phenotypic ratio and a 1:2:1 genotypic ratio for a completely dominant trait.
- Loop of Henle role
- A nephron structure that creates a salt gradient in the medulla by countercurrent multiplication, allowing water reabsorption and concentration of urine.
- Ideal gas law
- PV = nRT relates pressure, volume, moles, and absolute temperature of an ideal gas; R is 8.314 J mol−1 K−1.
- pH definition
- pH = −log[H+], a measure of hydrogen ion concentration; at 25 °C a neutral solution has pH 7 and Kw = 1.0 × 10−14.
- Le Chatelier’s principle
- When a system at equilibrium is disturbed by concentration, pressure, or temperature change, it shifts in the direction that opposes the disturbance.
- Oxidation and reduction
- Oxidation is loss of electrons and an increase in oxidation number; reduction is gain of electrons and a decrease in oxidation number.
- sp3 hybridization
- A mixing of one s and three p orbitals giving four equivalent hybrid orbitals with tetrahedral geometry and bond angles near 109.5°.
- Hess’s law
- The total enthalpy change of a reaction is independent of the route taken and equals the sum of enthalpy changes for individual steps.
- Colligative properties
- Properties such as boiling point elevation and freezing point depression that depend on the number of solute particles rather than their chemical identity.
- Kinematic equations
- For constant acceleration, v = u + at, s = ut + ½at², and v² = u² + 2as, relating velocity, displacement, acceleration, and time.
- Newton’s second law
- The net force on an object equals its mass times acceleration, F = ma, with acceleration in the direction of the net force.
- Ohm’s law
- For a conductor at constant temperature, current is directly proportional to voltage, V = IR, where R is resistance.
- Wave equation
- Wave speed equals frequency multiplied by wavelength, v = fλ; frequency is determined by the source and speed by the medium.
- Thin lens equation
- 1/f = 1/d_o + 1/d_i relates focal length, object distance, and image distance; magnification m = −d_i/d_o indicates image size and orientation.
- Coulomb’s law
- The electric force between two point charges is F = k|q1q2|/r², proportional to the charge product and inversely proportional to separation squared.
- Subject–verb agreement
- The verb must agree in number with its grammatical subject; intervening phrases do not change whether the subject is singular or plural.
- Comma splice
- An error that joins two independent clauses with only a comma; it is corrected with a semicolon, a conjunction, or a period.
- Affect versus effect
- Affect is usually a verb meaning to influence, while effect is usually a noun meaning result; effect can also be a verb meaning to bring about.
- Active versus passive voice
- In active voice the subject performs the action; in passive voice the subject receives it, using a form of be plus a past participle.
- Pronoun antecedent agreement
- A pronoun must match its antecedent in number and gender, and the antecedent should be clear to avoid ambiguous reference.
- Main idea of a passage
- The central point that the passage develops; it is often stated in a topic sentence and supported by details rather than being a minor fact.
- Contrapositive
- For a conditional 'If A then B,' the contrapositive 'If not B then not A' is logically equivalent; the converse is not.
- Correlation and causation
- A correlation between variables does not prove that one causes the other; possible explanations include reverse causation or a common cause.
- Necessary condition
- A condition required for an outcome: if the outcome occurs, the condition must hold, but the condition alone may not guarantee the outcome.
- Sufficient condition
- A condition that guarantees an outcome when present: if the condition holds, the outcome occurs, although other causes might also produce it.
- Valid syllogism
- An argument form in which, if the premises are true, the conclusion must be true; validity depends on logical form, not factual truth.