acid
substance that releases hydrogen ions (H+) when dissolved in water, an acidic solution has a pH less than 7
activation energy
minimum amount of energy needed for reactants to form products in a chemical reaction
active site
specific place where a substrate binds on an enzyme
amino acid
carbon compound joined by peptide bonds; building block of proteins
atom
building block of matter ; contains subatomic particles - neutrons, protons, and electron
base
substance that releases hydroxide ions (OH-) when dissolved in water; a basic solution has a pH greater than 7
buffer
mixture that can react w/ an acid or a base to maintain the pH within a specific range
carbohydrate
organic compound containing carbon, hydrogen, and oxygen in a ration of one oxygen and 2 hydrogen atoms for each carbon atom
catalyst
substance that speeds up a chemical reaction by reducing the activation energy
chemical reaction
energy-requiring process by which atom or group of atoms in substances are changed into different substances
compound
pure substance with unique properties; formed when two or more different elements combine
covalent bond
type of chemical bond formed when atoms share electrons
electron
negatively charged particle that occupies space around an atoms nucleus
element
pure substance composed of only one type of atom; cannot be broken down into another substance by physical or chemical means
enzyme
protein that speeds up a biological reaction by lowering the activation energy needed to start the reaction
hydrogen bond
weak electrostatic bond formed by the attraction of opposite charges between a hydrogen atom and an oxygen, fluorine, or nitrogen atom
ion
atom that is negatively or positively charged because it has lost or gained one or more electrons.
ionic bond
electrical attraction between two oppositely charged atoms or groups of atoms
isotope
two or more atoms of the same element having different numbers of neutrons
lipid
hydrophobic biological molecule composed mostly of carbon and hydrogen; hats, oils and waxes are ______.
macromolecule
large molecule formed by joining a smaller organic molecules together
mixture
combination of 2 or more different substances in which each substance keeps its individual characteristics; can have a uniform composition (homogeneous) or have distinct areas of substances (heterogeneous)
molecule
compound whose atoms are held together by covalent bonds
neutron
particle without a change in an atoms nucleus
nucleic acid
complex macromolecule that stores and communicate genetic information
nucleotide
a subunit of nucleic acid formed from a simple sugar, a phosphate group, and a nitrogenous base
nucleus
center of an atom; contains neutrons and protons. in eukaryotic cells, the central membrane-bound organelle that manages cellular functions and contains DNA
pH
measure of the concentration of hydrogen ions (H+) in a solution
polar molecule
molecule with oppositely charged regions
polymer
large molecule formed from smaller repeating units of identical or nearly identical, compounds linked by covalent bonds
product
substance formed by a chemical reaction; located on the right side of the arrow in a chemical equation
protein
organic compound made of amino acids joined by peptide bond; primary building block of organisms
proton
positively charged particle in an atoms nucleus
reactant
substance that exists before a chemical reaction starts; located on the left side of the arrow in a chemical equation
solute
substance dissolved in a solvent
solution
another name for a homogeneous mixture
solvent
substance in which another substance is dissolved
substrate
reactant to which an enzyme binds
van cler waals force
attractive forces between molecules