| A | B |
|---|
| atom | basic unit of matter |
| neutron | neutral particle in nucleus of atom |
| proton | positive particle in nucleus of atom |
| electron | negative particle orbiting the nucleus of the atom |
| nucleus | center of the atom |
| isotopes | atoms having the same number of protons but different numbers of neutrons |
| compound | formed by the chemical combination of two or more elements in definite proportions |
| ionic | bond in which electrons are transferred |
| covalent | bond in which electrons are shared |
| molecule | structure formed from covalent bonds |
| polar | molecule having a positive and a negative end |
| nonpolar | molecule without positive or negative ends |
| hydrogen | bond in which the oxygen of one molecule is attracted to the hydrogen of another |
| cohesion | attraction between molecules of the same substance |
| adhesion | attraction between molecules of different substances |
| mixture | composed of two or moe elements in compounds that are physically mixed together but not chemically combined |
| solution | ions dispersed evenly throughout a mixture |
| solute | thing that is dissolved in a solution |
| solvent | thing that does the dissolving in a solution |
| pH scale | shows the relative strength of acids and bases |
| acid | any compound that forms hydrogen ions in solution |
| base | compound that produces hydroxide ions in solution |
| carbon | element that has four valence electrons that can bond with other similar atoms |
| macromolecules | large molecules |
| monomers | smaller units of macromolecules |
| polymers | many monomers joined together |
| carbohydrates | energy molecules |
| monosaccharides | single-sugar molecules |
| polysaccharides | macromolecules formed from monosaccharides |
| lipids | used for energy storage and in membranes |
| nucleic acids | DNA and RNA |
| nucleotides | units of nucleic acids |
| proteins | used as strucural molecules and as channels in the cell membrane |
| amino acids | building blocks of proteins |
| chemical reaction | process that changes one set of chemicals to another set of chemicals |
| reactants | starting substances in chemical reactions |
| products | things produced in chemical reactions |
| activation energy | energy needed to start a reaction |
| catalyst | substance that speeds up a reaction |
| enzymes | proteins that act as biological catalysts |
| substrate | substances that enzymes act upon |
