atom
Smallest basic unit of MATTER
element
A substance made of only one type of atom that cannot be broken down by chemical means.
compound
Substance made of atoms of DIFFERENT elements that are bound together in a particular ratio.
isotope
Atoms that have the same number of protons but different number of NEUTRONS (Ex C-12, C-13, C-14)
ion
An atom that has gained or lost one or more ELECTRONS; will be positive or negative
ionic bond
Type of BOND that forms when electrons are TRANSFERRED from one atom to another
covalent bond
Type of BOND that forms when atoms SHARE a pair of electrons
molecule
Two or more atoms held together by covalent bonds
hydrogen bond
An attraction between a slightly positive hydrogen atom and a slightly negative atom
(Example: Between water molecules --> Causing cohesion)
cohesion
The attraction between like substances
adhesion
The attraction between different substances
solution
Mixture of two or more substances that is homogenous (same throughout)
solvent
In a solution, the substance in which the solute dissolves.
solute
The substance that dissolves in a solvent (what "you" put in)
acid
A compound that release hyrdogen ions (H+) when dissolved in water; higher H+ concentration. pH below 7
base
A compound that releases hydroxide (OH-) ions in a solution; has a lower hydrogen ion concentration in a solution. pH above 7
pH
Measuring unit for acidity. (acids <7, bases >7)
monomer
a building block of a polymer
polymer
A large molecule (macromolecule) made of many monomers bonded together.
carbohydrate
Molecules composed of carbon, hydrogen and oxygen in a 2:1 ratio of H to O (carb= carbon, hydrate=water) (Ex. monosaccharides and polysaccharides)
lipid
Nonpolar molecules that include fats, oils, and cholesterol (This organic polymer is composed of 1 glycerol + 3 fatty acids)
fatty acid
One of the building blocks (monomer) that makes up lipids
protein
An organic polymer composed of monomers called amino acids
amino acids
Any one of 20 different organic molecules that combine to form proteins
nucleic acids
Polymers that are made up of monomers called nucleotides (Ex: DNA & RNA)
chemical reactions
Process that changes substances into different substances by breaking and forming chemical bonds
reactants
Substances that participates a chemical reaction (Left side of arrow)
product
Substance formed in a chemical reaction (Right side of arrow)
bond energy
The amount of energy that will break a bond between two atoms
equilibrium
The state reached when both reactants and products are made at the same rate.
activation energy
Energy needed to get a reaction started
exothermic
A chemical reaction in which energy is GIVEN OFF in the form of heat (Also exergonic reaction)
endothermic
A chemical reaction that TAKES IN or REQUIRES heat energy (Also endergonic reaction)
catalyst
A substance that decreases the activation energy needed to start a chemical reaction. (So... It speeds up the reaction)
enzymes
BIological catalysts for chemical reactions in LIVING THINGS; made of proteins
substrates
Specific reactants that an enzyme acts on
polar molecule
a molecule that has a partial positive end and a partial negative end because of unequal sharing of electrons
dehydration synthesis reaction
A chemical reaction in which two molecules are bonded together with the removal of a water molecule. (Ex - Monosaccharides bond together through this process to form polysaccharides)
hydrolysis reaction
A chemical reaction that breaks apart a larger molecule by adding a molecule of water (Ex - Proteins break down into amino acids through hydrolysis)