ap bio unit 2 vocab

Essential element

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

Element

Form of matter made up of a single type of atom

Macroelement

Any chemical element that makes up a large portion of the body of living organisms

Trace element

any chemical element required by living organisms in minute amounts

Compound

a substance formed by two or more elements chemically bonded

Molecule

The result of two or more atoms covalently bonded and is the smallest part of any covalent compound

Covalent bond

A strong chemical bond in which two atoms share one or more pairs of valence electrons

Polar bond

A covalent bond between atoms with a relatively large difference in electronegativity, so that the electrons are not shared equally

Nonpolar bond

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

Ionic bond

A chemical bond resulting from the attraction between oppositely charged ions formed by the exchange of valence electrons

Electronegativity

the tendency of an atom to attract electrons when chemically bonded

Hydrogen bond

The strongest and most important example of dipole interaction in biology

Dipole interaction

Weak attractions between polar molecules

Van der Waals

Weak attractions between molecules or parts of molecules that result from temporary distribution of partial charges

Adhesion

The clinging of one substance to surfaces

Cohesion

The linking together of like molecules

Surface tension

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

calorie (lower case)

unit of heat defined as the quantity of heat required to raise the temperature of 1 gram of water by 1 degree Celsius at atmospheric pressure

Specific heat capacity

The amount of heat that must be absorbed or lost for 1 g of a substance to change its temperature by 1 degree Celsius

Heat of vaporization

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

Evaporative cooling

The process in which the surface of an object becomes cooler during evaporation

Solution

A mixture that consists of a solute and a solvent

Solvent

a substance capable of dissolving other substances

Solute

the dissolved substance in a solution

Hydrophilic

any substance that has a strong affinity for water

Hydrophobic

any substance that does not have an affinity for water

hydrogen ion

a positively charged ion (H+) formed of a hydrogen atom that has lost its electron

pH scale

measurement system used to indicate the concentration of hydrogen ions (H+) in solution

Buffer

A solution that minimizes changes in pH when extraneous acids or bases are added to the solution

Acid precipitation

precipitation, such as rain, sleet, or snow, that contains a high concentration of acids, often because of the pollution of the atmosphere

Organic chemistry

the study of compounds containing carbon

Hydrocarbon

an organic compound containing only carbon and hydrogen

Isomer

a compound that exists in forms having different arrangements of atoms but with the same molecular mass

Structural isomer

One of several compounds that have the same molecular formula but differ in the covalent arrangements of their atoms

Geometric isomers

Molecules that differ in arrangement around a double bond

Enantiomer

either one of a pair of compounds that are mirror images on each other

Functional group

A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules

Hydroxyl group

A functional group consisting of an oxygen atom bonded to a hydrogen atom

Alcohol

A chemical compound containing the hydroxyl group

Carbonyl group

A functional group that consists of a carbon atom double bonded to an oxygen atom (C=O)

Aldehyde

Compound that contains a terminal carbonyl group

Ketone

Compound that contains a non-terminal carbonyl group

Carboxyl group

A functional group consisting of a single carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group

Carboxylic acid

A chemical compound that contains a carboxyl group

Amino group

A functional group consisting of a nitrogen bonded to two hydrogens

Amine

A chemical compound that contains an amino group

Amino acids

Biologically important organic compounds that contain the amino and carboxylic acid functional groups

Sulfhydryl group

A functional group that contains a sulfur atom bonded to a hydrogen atom

Thiol

Organic compounds that have a sulfhydryl functional group

Phosphate group

A functional group comprised of phosphorus attached to four oxygen, and with a net negative charge

Organic phosphate

Compounds containing phosphate groups

ATP (Adenosine triphosphate)

An important molecule that provides cellular energy in nearly all life forms

Asymmetric carbon

A carbon atom attached to four different types of atoms or four different groups of atoms

hyrdration shell

sphere of water molecules around a dissolved ion

dipole-dipole

attractions between oppositely charged regions of polar molecules

hyrdoxide ion

a water molecule that has lost a proton; OH-