Chapter 2: Elements and atoms: the building blocks of matter

acis

compound that releases hydrogen ions in solution

activation energy

amount of energy greater than the energy contained in the reactants, which must be overcome for a reaction to proceed in a chemical reaction.

adenosine triphosphate (ATP)

nucleotide containing ribose and an adenine base that is essential in energy transfer

amino acid

building blocks of protein

anion

atom with negative energy

atom

An atom is the smallest quantity of an element that retains the unique properties of that element

atomic number

The number of protons in a nucleus 

atomic mass

The number of positively charged protons and non-charged neutrons.

base

compound that accepts hydrogen ions in solution

bond

electrical force linking atoms

buffer

solution containing a weak acid or a weak bass that opposes wide fluctuations in the pH of the body and oxygen

carbohydrate

class of organic compounds built from sugars, molecules containing carbon, hydrogen, and oxygen in a 1-2-1 ratio

catalyst

substance that increase the rate of a chemical reaction without itself being changed in the process

cation

atom with a positive charge

chemical energy

form of energy that is absorbed as a chemical bonds form, stored as they maintained, and released as they are broken

colloid

is a mixture that is somewhat like a heavy solution.

compound

substance composed of two or more different elements joined by chemical bonds

concentration

number of particles within given space

covalent bond

chemical bond in which two atoms share electrons, thereby completing their valence shells

decomposition reaction

type catabolic reaction in which one or more bonds within a larger molecule are broken, resulting in the release of smaller molecules or atoms

denaturation

changes in the structure of a molecule through physical or chemical means

deoxyribonucleic acid (DNA)

deoxyribose-containing nucleotide that stores genetic information

disaccharide

pair of carbohydrate monomers bonded by dehydration synthesis

disulfide bond

covalent bond formed within a polypeptide between sulfide groups of sulfur-containing amino acids

electron

subatomic particles having a negative charge and nearly no mass, found orbiting the atoms’s nucleus

electron shell

area of space a given distance from an atom’s nucleus in which electrons are grouped

element

substance that cannot be created or broken down by ordinary chemical means

enzyme

protein or RNA that catalyzes chemical reactions

exchange reaction

type of chemical reaction in which bonds are both formed and broken , resulting as a distinct unit in chemical reactions with other atoms

functional group

group if atoms linked by strong covalent bonds that trends to behave as distinct unit in chemical reactions with other atoms

hydrogen bond

dipole-bond in which a hydrogen atom covalently bonded to an electronegative atom is weakly attracted to a second electronegative atom

inorganic compound

substance that does not contain both carbon and hydrogen

ion

atom with an overall positive or negative charge

isotope

one of the variations of an element in which the number of neutrons differ from each other

kinetic energy

energy that matter possesses because of its motion

lipid

class of non polar organic compounds built from hydrocarbons and distinguished by the fact that they are not soluble in water

macromolecule

large molecule formed by covalent bonding

mass number

sum of the number of protons and neutrons

matter

physical substance, that occupies space and has mass

molecule

two or more atoms covalently bonded together

monosaccharide

monomer of carbohydrate; also known as simple sugar

neutron

heavy subatomic particles having no electrical charge and found in the atom’s nucleus

nucleotide

class of organic compounds composed of one or more phosphate group

organic compound

substance that contains both carbon and hydrogen

peptide bond

covalent bond formed by dehydration synthesis between two amino acids

periodic table of the elements

arrangement of the elements in the table according to their atomic number

pH

negative logarithm of the hydrogen ion concentration of a solution

phospholipid

a lipid compound in which a phosphate group is combined with a diglyceride

potential energy

stored energy matter that possesses because of the positioning or structure of its components

proton

heavy subatomic particles having a positive charge and found in the atom’s nucleus

radioactive isotope

unstable, heavy isotope that gives off subatomic particles. or electromagnetic energy, as it decays

reactant

one or more substance that enter into the reaction

ribonucleic acid (RNA)

ribose-containing nucleotide that help manifest the genetic code as protein

solution

homogeneous liquid mixture in which a solute is dissolved into molecules within a solvent

steroid

lipid compound composed of four hydrocarbon rings bonded to a variety of other atoms and molecules

substrate

reactant in an enzymatic reaction

suspension

liquid mixture in which particles distributed in the liquid settle out over time

synthesis reaction

type of anabolic reaction in which two or more atoms or molecules bond, resulting in the molecule bonded with three fatty acids chains

valance shell

outermost electron shell of an atom