OAT Physics key terms

The net movement of water across a selectively permeable membrane from a region of higher water concentration to one of lower water concentration, driven by differences in solute concentration.

A solution with a higher solute concentration than the cell placed in it, causing water to leave the cell and the cell to shrink or crenate.

The ability of an external solution to cause water to move into or out of a cell, determined by comparing solute concentrations across the membrane.

A membrane enzyme that uses the flow of protons down their electrochemical gradient to phosphorylate ADP, producing ATP during oxidative phosphorylation and photosynthesis.

The coupling of a proton gradient across a membrane to ATP synthesis, as protons flow back through ATP synthase in mitochondria and chloroplasts.

The final stage of aerobic respiration in which electrons passed along the electron transport chain pump protons, and the resulting gradient drives ATP production.

One of two or more alternative versions of a gene at a given locus, which may produce different observable traits in an organism.

The specific combination of alleles an organism carries for a gene or set of genes, which together with environment influences phenotype.

The observable physical or biochemical characteristics of an organism, resulting from the interaction of its genotype with the environment.

A concentration unit expressing the number of moles of solute dissolved per liter of solution, abbreviated M.

The amount of substance containing Avogadro's number (6.022 x 10^23) of representative particles, used to convert between mass and particle count.

The mass in grams of one mole of a substance, numerically equal to its formula weight in atomic mass units.

The quantitative relationship between amounts of reactants and products in a balanced chemical equation, used to calculate yields and required quantities.

The reactant that is completely consumed first in a chemical reaction, determining the maximum amount of product that can form.

The maximum amount of product predicted from stoichiometry when the limiting reactant is fully consumed, before accounting for losses.

The actual experimental yield of product divided by the theoretical yield, multiplied by 100 to express efficiency as a percentage.

When a system at equilibrium is disturbed by a change in concentration, pressure, or temperature, it shifts in the direction that partially offsets the disturbance.

The ratio of product concentrations to reactant concentrations, each raised to its stoichiometric coefficient, at equilibrium for a given reaction at a fixed temperature.

A substance that donates a proton (hydrogen ion) to another species in a chemical reaction, forming its conjugate base.

A logarithmic measure of hydrogen ion concentration in solution, defined as the negative base-10 logarithm of the molar hydrogen ion concentration.

A solution of a weak acid and its conjugate base, or a weak base and its conjugate acid, that resists large changes in pH when acid or base is added.

A relationship giving buffer pH as pKa plus the logarithm of the ratio of conjugate base concentration to weak acid concentration.

The geometric property of a molecule that is not superimposable on its mirror image, usually due to a carbon bonded to four different groups.

An atom, typically carbon, bonded to four different substituent groups so that interchanging two groups produces a different stereoisomer.

One of a pair of stereoisomers that are non-superimposable mirror images of each other, differing in configuration at every stereocenter.

An electron-rich species that donates an electron pair to an electron-poor atom to form a new covalent bond in a substitution or addition reaction.

An electron-deficient species that accepts an electron pair from a nucleophile, often a carbocation or a polarized carbonyl carbon.

A one-step bimolecular nucleophilic substitution in which the nucleophile attacks as the leaving group departs, inverting stereochemistry at the carbon.

A two-step nucleophilic substitution that proceeds through a carbocation intermediate, with the rate depending only on substrate concentration and giving racemization.

In electrophilic addition of HX to an alkene, the hydrogen adds to the carbon with more hydrogens, placing the halogen on the more substituted carbon.

The central point or controlling claim a passage develops, which the other sentences support; often stated in a thesis sentence.

Specific evidence, examples, or reasons in a passage that explain, illustrate, or strengthen the main idea rather than introduce a new topic.

A conclusion drawn from evidence in a passage that is not stated directly, requiring the reader to combine stated facts logically.

A comparison of two quantities by division, expressing how many times one value contains or is contained within another.

An equation stating that two ratios are equal, used to solve for an unknown quantity when the relationship is constant.

A rate expressed as a quantity per single unit of another quantity, such as miles per one hour or cost per one item.

The net force on an object equals its mass times its acceleration, so acceleration is proportional to net force and inversely proportional to mass.

The vector sum of all individual forces acting on an object, which determines the object's resulting acceleration.

A sketch showing an object as a point with all external forces drawn as labeled arrows, used to set up force equations.

The principle that total energy in a closed system remains constant, though it may convert between kinetic, potential, and other forms.

The energy an object possesses due to its motion, equal to one-half its mass times the square of its speed.

Stored energy an object has because of its position or configuration, such as gravitational energy depending on height above a reference level.

The bending of light as it passes from one medium into another with a different index of refraction, caused by a change in wave speed.

The ratio of the speed of light in vacuum to its speed in a given medium, describing how strongly that medium bends light.

A relationship stating that the product of refractive index and sine of the angle from the normal is constant across an interface between two media.