Fundamental Building Blocks

Vocabulary

amphipathic molecule

molecule that has both hydrophobic and hydrophilic portions

anion

negatively charged ion

carbohydrate

organic molecule that contains carbon, hydrogen, and oxygen and provides energy to cells

cation

positively charged ion

chemical bond

attractive force that joins atoms or ions

compound

substance made of atoms of two or more elements bonded together in a certain ratio

concentration

amount of solute dissolved in a given volume of solvent

covalent bond

chemical bond that forms when valence electrons are shared between atoms

electrolyte

ionic solution that can be decomposed by electricity

electron

negatively charged subatomic particle

hydrated

solvated by water molecules

hydrogen bond

weak intermolecular force that results from an attraction between a positively charged hydrogen atom in one molecule and a negatively charged atom in a nearby molecule

hydrophilic

having a strong affinity toward water

hydrophobic

having a weak or no affinity to water

inorganic compound

compound consisting of molecules that do not contain a carbon-hydrogen bond

ion

charged particle formed when an atom gains or loses electrons

ionic bond

chemical bond that forms when valence electrons are transferred between atoms

isotope

one of two or more atoms of an element that have the same number of protons but different numbers of neutrons

lipid

long-chain hydrocarbon that is soluble in nonpolar solvents, that is, solvents without charge

molecule

group of atoms held together by one or more covalent bonds

neutralization

chemical reaction in which an acid and a base in solution interact, producing salt and water and changing the pH

neutron

subatomic particle that has a neutral charge in the nucleus of an atom

nonpolar covalent bond

covalent bond that forms when two atoms share electrons equally

nucleic acid

molecule made of nucleotides. It exists in cells in two forms: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

organic compound

compound consisting of molecules that contain one or more carbon-hydrogen bonds

phospholipid

molecule composed of a phosphate group, fatty acids, and glycerol

polar covalent bond

covalent bond in which the electron density is more localized on one end of the bond. One end is slightly positive, and one end is slightly negative.

protein

large molecule composed of amino acids

proton

positively charged subatomic particle in the nucleus of an atom

van der Waals force

weakest intermolecular force, which forms because of attraction between molecules