FINAL AP BIOLOGY REVIEW (ALL UNITS #1-8) -

MATTER

anything that takes up space and has mass

ELEMENT

any substance that cannot be broken down to any other substance by chemical reactions

MATTER

anything that takes up space and has mass

ELEMENT

any substance that cannot be broken down to any other substance by chemical reactions

COMPOUND

a substance consisting of two or more different elements combined in a fixed ratio

ESSENTIAL ELEMENT

a chemical element required for an organism to survive, grow, and reproduce

TRACE ELEMENT

an element indispensable for life but required in extremely minute amounts

ATOM

the smallest unit of matter that retains the properties of an element

NEUTRON

a subatomic particle having no electrical charge (electrically neutral), with a mass of about 1.7(10^-24) grams; found in the nucleus of an atom

PROTON

a subatomic particle with a single positive electrical charge, with a mass of about 1.7(10^-24) grams; found in the nucleus of an atom

ELECTRON

a subatomic particle with a single negative electrical charge and a mass about 1/2,000 that of a neutron or proton; one or more electrons move around the nucleus of an atom

ATOMIC NUCLEUS

an atom’s dense central core, containing protons and neutrons

DALTON

a measure of mass for atoms and subatomic particles; the same as the atomic mass unit (amu)

ATOMIC NUMBER

the number of protons in the nucleus of an atom, unique for each element and designated by a subscript

MASS NUMBER

the total number of protons and neutrons in an atom’s nucleus

ATOMIC MASS

the total mass of an atom, numerically equivalent to the mass in grams of one mole of the atom (for an element with more than one isotope, the atomic mass is the average mass of the naturally occurring isotopes, weighted by their abundance)

ISOTOPE

one of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass

RADIOACTIVE ISOTOPE

an isotope (an atomic form of a chemical element) that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy

ENERGY

the capacity to cause change, especially to do work (to move matter against an opposing force)

POTENTIAL ENERGY (P.E.)

the energy that matter possesses as a result of its location or spatial arrangement (structure)

ELECTRON SHELL

an energy level of electrons at a characteristic average distance from the nucleus of an atom

VALENCE ELECTRON

an electron in the outermost electron shell

VALENCE SHELL

the outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom

CHEMICAL BOND

an attraction between two atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms; the bonded atoms gain complete outer electron shells

MOLECULE

two or more atoms held together by covalent bonds

SINGLE BOND

a single covalent bond; the sharing of a pair of valence electrons by two atoms

DOUBLE BOND

a double covalent bond; the sharing of two pairs of valence electrons by two atoms

VALENCE

the bonding capacity of a given atom; the number of covalent bonds an atom can form, which usually equals the number of unpaired electrons in its outermost (valence) shell

ELECTRONEGATIVITY

the attraction of a given atom for the electrons of a covalent bond

NONPOLAR COVALENT BOND

a type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity

POLAR COVALENT BOND

a covalent bond between atoms that differ in electronegativity; the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive

ION

an atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge

CATION

a positively charged ion

ANION

a negatively charged ion

IONIC BOND

a chemical bond resulting from the attraction between oppositely charged ions

IONIC COMPOUND

a compound resulting from the formation of an ionic bond; also called a salt

HYDROGEN BOND

a type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule

VAN DER WAALS INTERACTIONS

weak attractions between molecules or parts of molecules that result from transient local partial charges

REACTANT

a starting material in a chemical reaction

PRODUCT

a material resulting from a chemical reaction

CHEMICAL EQUILIBRIUM

in a chemical reaction, the state in which the rate of the forward reaction equals the rate of the reverse reaction, so that the relative concentrations of the reactants and products do not change with time

POLAR MOLECULE

a molecule (such as water) with an uneven distribution of charges in different regions of the molecule

COHESION

the linking together of like molecules, often by hydrogen bonds

ADHESION

the clinging of one substance to another, such as water to plant cell walls, by means of hydrogen bonds

SURFACE TENSION

a measure of how difficult it is to stretch or break the surface of a liquid

THERMAL ENERGY

kinetic energy due to the random motion of atoms and molecules; energy in its most random form

KINETIC ENERGY (K.E.)

the energy associated with the relative motion of objects; moving matter can perform work by imparting motion to other matter

TEMPERATURE

a measure in degrees of the average kinetic energy (thermal energy) of the atoms and molecules in a body of matter

HEAT

thermal energy in transfer from one body of matter to another

CALORIE (cal)

the amount of heat energy required to raise the temperature of 1g of water by 1°C; also the amount of heat energy that 1g of water releases when it cools by 1°C; the Calorie (with a capital C), usually used to indicate the energy content of food, is a kilocalorie

JOULE (J)

a unit of energy: 1(J) = 0.239 cal; one cal = 4.184(J)

SPECIFIC HEAT

the amount of heat that must be absorbed or lost for 1g of a substance to change its temperature by 1°C

HEAT OF VAPORIZATION

the quantity of heat a liquid must absorb for 1g of it to be converted from the liquid to the gaseous state

EVAPORATIVE COOLING

the process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state

SOLUTION

a liquid that is a homogeneous mixture of two or more substances

SOLVENT

the dissolving agent of a solution; water is the most versatile dissolving agent known

SOLUTE

a substance that is dissolved in a solution

AQUEOUS SOLUTION

a solution in which water is the solvent

HYDRATION SHELL

the sphere of water molecules around a dissolved ion

HYDROPHILIC

having an affinity for water

HYDROPHOBIC

having no affinity for water; tending to coalesce and form droplets in water

MOLECULAR MASS

the sum of the masses of all the atoms in a molecule; sometimes called molecular weight

MOLE (mol)

the number of grams of a substance that equals its molecular weight in daltons and contains Avogadro’s number of molecules

MOLARITY

a common measure of solute concentration, referring to the number of moles of solute per liter of solution

HYDROGEN ION (H+)

a single proton with a charge of 1+; the dissociation of a water molecule (H2O) leads to the generation of a hydroxide ion (OH-) and a hydrogen ion (H+); in water, H+ is not found alone but associates with a water molecule to form a hydronium ion

HYDROXIDE ION (OH-)

a water molecule that has lost a proton; OH-

HYDRONIUM ION (H3O+)

a water molecule that has an extra proton bound to it; H3O+, commonly represented as H+

ACID

a substance that increases the hydrogen ion concentration of a solution

BASE

a substance that reduces the hydrogen ion concentration of a solution

pH

a measure of hydrogen ion concentration equal to -log[H+] and ranging in value from 0 to 14

BUFFER

a solution that contains a weak acid and its corresponding base; minimizes changes in pH when acids or bases are added to the solution

OCEAN ACIDIFICATION

the process by which the pH of the ocean is lowered (made more acidic)

ORGANIC COMPOUND

a chemical compound containing carbon

MACROMOLECULE

a giant molecule formed by the joining of smaller molecules, usually by a dehydration reaction

VALENCE

the bonding capacity of a given atom; the number of covalent bonds an atom can form, which usually equals the number of unpaired electrons in its outermost (valence) shell

HYDROCARBON

an organic molecule consisting of only carbon and hydrogen

ISOMER

one of two or more compounds that have the same numbers of atoms of the same elements but different structures and hence different properties

STRUCTURAL ISOMER

one of two or more compounds that have the same molecular formula but differ in the covalent arrangements of their atoms

CIS-TRANS ISOMER

one of two or more compounds that have the same molecular formula and covalent bonds between atoms but differ in the spatial arrangements of their atoms owing to the inflexibility of double bonds; formerly called a geometric isomer

ENANTIOMER

one of two compounds that are mirror images of each other and that differ in shape due to the presence of an asymmetric carbon

FUNCTIONAL GROUP

a specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions

ADENOSINE TRIPHOSPHATE (ATP)

an adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed; this energy is used to drive endergonic reactions in cells

POLYMER

a long molecule consisting of many similar or identical monomers linked together by covalent bonds

MONOMER

the subunit that serves as the building block of a polymer

ENZYME

a macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction; most are proteins

DEHYDRATION REACTION

a chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule

HYDROLYSIS

a chemical reaction that breaks bonds between two molecules by the addition of water; functions in disassembly of polymers to monomers

CARBOHYDRATE

a sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides)

MONOSACCHARIDE

the simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides; also known as simple sugars, they have molecular formulas that are generally some multiple of CH2O

DISACCHARIDE

a double sugar, consisting of two monosaccharides joined by a glycosidic linkage formed by a dehydration reaction

GLYCOSIDIC LINKAGE

a covalent bond formed between two monosaccharides by a dehydration reaction

POLYSACCHARIDE

a polymer of many monosaccharides, formed by dehydration reactions

STARCH

a storage polysaccharide in plants, consisting entirely of glucose monomers joined by α glycosidic linkages

GLYCOGEN

an extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch

CELLULOSE

a structural polysaccharide of plant cell walls, consisting of glucose monomers joined by β glycosidic linkages

CHITIN

a structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeletons of all arthropods

LIPID

any of a group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly, if at all, with water

FAT

a lipid consisting of three fatty acids linked to one glycerol molecule; also called a triacylglycerol or triglyceride

FATTY ACID

a carboxylic acid with a long carbon chain; varies in length and in the number and location of double bonds

TRIACYLGLYCEROL

a lipid consisting of three fatty acids linked to one glycerol molecule; also called a fat or triglyceride

SATURATED FATTY ACID

a fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms attached to the carbon skeleton

UNSATURATED FATTY ACID

a fatty acid that has one or more double bonds between carbons in the hydrocarbon tail; such bonding reduces the number of hydrogen atoms attached to the carbon skeleton