| A | B |
|---|
| atom | the basic unit of matter |
| nucleus | strong forces bind protons and neutrons together to form the nucleus. |
| electron | a negatively charged particle (-) with 1/1840 the mass of a proton. |
| element | a pure substance that consists entirely of one type of atom |
| isotopes | atoms of the same elements that differ in the number of neutorns they contain. |
| ionic bond | formed when one or more electrons are transferred from one atom to another. |
| ions | positively and negatively charged atoms. |
| convalent bond | forms when electrons are shared between atoms. |
| cohension | an attraction between molecules of the same substance |
| adhesion | an attraction between molecules of different substances. |
| mixture | material composed of two or more elements |
| solution | A homogeneous, liquid mixture of two or more substances.solvent The dissolving agent of a solution |
| solvent | The dissolving agent of a solution |
| suspension | nondissolved materials |
| pH scale | A measure of hydrogen ion concentration equal to –log [H+] and ranging in value from 0 to 14 |
| acid | A substance that increases the hydrogen ion concentration in a solution |
| base | A substance that reduces the hydrogen ion concentration in a solution |
| buffer | A substance that consists of acid and base forms in solution and that minimizes changes in pH when extraneous acids or bases are added to the solution |
| monomer | The subunit that serves as the building block of a polymer |
| polymer | A large molecule consisting of many identical or similar monomers linked together |
| carbohydrate | A sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides) |
| monosaccharide | A The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides |
| polysaccharide | A polymer of up to over a thousand monosaccharides, formed by condensation synthesis |
| lipid | One of a family of compounds, including fats, phospholipids, and steroids, that are insoluble in water |
| nucleic acid | A polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities |
| nucleotide | The building block of a nucleic acid, consisting of a five-carbon sugar covently bonded to a nitrogenous base and a phosphate group |
| RNA | A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis and as the genome of some viruses |
| DNA | A double-stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins |
| protein | A three-dimensional biological polymer constructed from a set of 20 different monomers called amino acids |
| amino acid | An organic molecule possessing both carboxyl and amino groups. Amino acids serve as the monomers of proteins |
| chemical reaction | A process leading to chemical changes in matter; involves the making and/or breaking of chemical bonds |
| reactant | A starting material in a chemical reaction |
| product | An autotrophic organism, usually a photosynthesizer, that contributes to the net primary productivity of a community |
| activation energy | The energy that must be possessed by atoms or molecules in order to react |
| catalyst | A substance that lowers the activation energy of a chemical reaction by forming a temporary association with the reacting molecules; as a result, the rate of the reaction is accelerated. Enzymes are catalysts |
| enzyme | A class of proteins serving as catalysts, chemical agents that change the rate of a reaction without being consumed by the reaction |
| substrate | The substance on which an enzyme works |
| solute | A substance that is dissolved in a solution |
