Biology The Chemistry of Life Review exam questions and answers.

Atom The basic unit of matter Nucleus In cells, structure that contains the cell's genetic material in the form of DNA Electron Negatively charged particle; located in the space surrounding the nucleus Element Pure substance that consists entirely of one type of atom Isotope One of several forms of a single element, which contains the same number of protons but different numbers of neutrons Compound Substance formed by the chemical combination of two or more elements in definite proportions Ionic Bond Chemical bond formed when one or more electrons are transferred from one atom to another Ion Atom that has a positive or negative charge Covalent Bond Type of bond between atoms in which the electrons are shared Molecule Smallest unit of most compounds that displays all the properties of that compound van der Waals Forces Slight attraction that develops between oppositely charged regions of nearby molecules Hydrogen Bond Weak attraction between a hydrogen atom and another atom Cohesion Attraction between molecules of the same substance Adhesion Force of attraction between different kinds of molecules Mixture Material composed of two or more elements or compounds that are physically mixed together but not chemically combined Solution type of mixture in which all the components are evenly distributed Solute Substance that is dissolved in a solution Solvent Dissolving substance in a solution Suspension Mixture of water and nondissolved material pH Scale Scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution; a pH of 0 to 7 is acidic, a pH of 7 is neutral, and a pH of 7 to 14 is basic Acid A compound that forms hydrogen ions (H+) in solution; a solution with a pH of less than 7 Base A compound that produces hydroxide ions (OH-) in solution; a solution with a pH of more than 7 Buffer A compound that prevents sharp, sudden changes in pH Monomer Small chemical unit that makes up a polymer Polymer Molecules composed of many monomers; makes up macromolecules Carbohydrate Compound made up of carbon, hydrogen, and oxygen atoms; type of nutrient that is the major source of energy for the body Lipid Macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes Nucleotide Subunit of which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitroge