| A | B |
|---|
| atom | the basic unit of matter |
| nucleus | the center of the atom |
| electron | a negatively charged particle |
| element | a pure substance that consists entirely of one type of atom |
| isotope | atoms of the same element that differ in the number of neutrons they contain |
| compound | a substance formed by the chemical combinsation of two or more elements in definite proportions |
| ionic bond | formed when one or more electrons are transferred from one atom to another |
| ion | positively and negatively charged atoms |
| covalent bond | forms when electrons are shared between atoms |
| molecule | the smallest unit of most compounds |
| vander Waals forces | intermolecular forces of attraction |
| cohesion | an attraction between molecules of the same substance |
| adhesion | an attraction between molecules of different substances |
| mixture | a material composed of two or more elements or compounds that are physically mixed together but not chemically combined |
| solution | the gradual disbersement of ions in water forming a type of mixture |
| solute | the substance that is disolved |
| suspension | a mixture of water and nondisolved material |
| pH scale | a measurement system used to identify the concentration of H+ ions in a solution |
| acid | any compound that forms H+ ions in a solution |
| base | a compound that produces hydroxide ions in a solution |
| buffer | weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH |
| monomer | smaller compounds |
| polymer | a larger compound that is formed when small compounds are joined together |
| carbohydrate | compounds made up of carbon, hydrogen, and oxygen atoms |
| monosaccharide | single sugar molecules |
| polysaccharide | large macromolecules formed from monosaccharides |
| lipid | a large and varied group of biological molecules that are generally not soluble in water |
| nucleic acid | macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus |
| ribonucleic acid (RNA) | a single-stranded nucleic acid that contains the sugar ribose |
| deoxyribonucleic acid (DNA) | a nucleic acid that contains the sugar deoxyribose |
| protein | macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen |
| amino acid | compounds with an amino acid group on one end and a carboxyl group on the other end |
| chemical reaction | a process that changes one set of chemicals into another set of chemicals |
| reactant | the elements or compounds that enter into a chemical reaction |
| product | the elements or compounds produced by a chemical reaction |
| activation energy | the energy that is needed to get a reaction started |
| catalyst | a sbstance that speeds up the rate of a chemical reaction |
| enzyme | proteins that act as biological catalysts |
| substrate | the reactants of enzyme-catalyzed reactions |
| solvent | the substance in which the solute disolves |
| nucleotides | consist of three parts: a 5-carbon sugar, a phosphate and a nitrogenous base |
