| A | B |
|---|
| element | Substance that cannot be broken down into simpler chemical substances. |
| Atom | Smallest particle of an element that has all the characteristics of that element; basic building blocks of matter. |
| Nucleus | Positive charged center of an atom; contains neutrons, positively charged protons, and is surrounded by negatively charged electron clouds. |
| Isotope | Atoms of the same element that have different numbers of neutrons in the nucleus. |
| Compound | Substance composed of two or more atoms of two or more different elements that are chemically combined. |
| Covalent Bond | Chemical bond formed when two atoms combine by sharing electrons. |
| Molecule | Group of atoms held together by covalent bonds; has no overall charge. |
| Ion | Atom or group of atoms that gains or loses electrons; has a positive or negative electrical charge. |
| Ionic Bond | Chemical bond formed by the attractive forces between two ions of opposite charge. |
| Metabolism | Total of all chemical reactions that occur within an organism. |
| Mixture | Combination of substances in which individual components do not combine chemically but retain their individual properties. |
| Solution | Mixture in which one or more substances are distributed evenly in another substance. |
| pH | Measure of how acidic or basic a solution is; scale ranges from 0 to 14. |
| Acid | Any substance that forms hydrogen ions in water and has a pH below 7. |
| Base | Any substance that forms hydroxide ions in water and has a pH above 7. |
| Polar Molecule | A molecule with an unequal distribution of charge, resulting in a positive end and a negative end. |
| Hydrogen Bond | Weak chemical bond formed by attraction of positively charged hydrogen atoms to other negatively charged atoms. |
| Diffusion | Net, random movement of particles from an area of higher concentration to an area of lower concentration, eventually resulting in even distribution. |
| Dynamic Equilibrium | Result of diffusion where there is continuous movement of particles but no overall change in concentration. |
| Isomer | Compounds with the same simple formula but different three-dimensional structures, resulting in different physical and chemical properties. |
| Polymer | Large molecule formed when many smaller molecules bond together. |
| Carbohydrate | Organic compound used by cells to store and release energy; composed of carbon, hydrogen, and oxygen. |
| Lipid | Organic compounds commonly called fats and oils; insoluable in water; used by cells for long-term energy storage, insulation, and protective coatings. |
| Protein | Large, complex polymer essential to all life composed of carbon, hydrgen, oxygen, nitrgen and sometimes sulfur: provides structure for tissuse and organs and helps carry out cell metabolism. |
| Amino acids | Basic building blocks of proteins. |
| Peptide bond | Covalent bond linking amino acids. |
| Enzyme | Type of protein found in all living things that increasees the rate of chemical reactions. |
| Nucleic acid | Complex macromolecules such as DNA and RNA, that store information in cells coded form. |
| Nucleotide | Subunits of nucleic acid formed from a simple sugar, a nitrogen base, and a phosphate group. |
