Term | Definition |
Atom | The basic unit of matter |
Nucleus | The center of an atom, which contains the protons and neutrons; 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 elements, which contains the same number of protons but different numbers of neutrons. |
Compound | Substance formed by the chemical combination of 2 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 | A formation made by the moving electrons traveling around the nuclei of two atoms. |
Molecule | Smallest unit in 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 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 and a pH level of 7 to 14 is basic. |
Acid | Compound that forms hydrogen ions in solution; a solution with a pH of less than 7. |
Base | Compound that produces hydroxide ions in solution; solution with a pH of more than 7. |
Buffer | 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. |
Monosaccharide | simple sugar molecule. |
Lipid | Macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes. |
Nucleic Acid | macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus. |
Nucleotide | Subunit of which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base. |
Protein | macromolecules that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair. |
Amino Acid | Compound with an amino group on one end and carboxyl group on the other end. |
Chemical Reactant | process that changes, or transforms, one set of chemicals into another set of chemicals. |
Reactant | elements or compounds that enter into a chemical reaction. |
Product | elements or compounds produced by a chemical reaction. |
Activation Energy | Energy that is needed to get a reaction started. |
Catalyst | Substance that speeds up the rate of chemical reactions. |
Enzyme | Protein catalyst that speeds up the rate of specific biological reactions. |
Substrate | reactant of an enzyme- catalyzed reaction. |