Terms : Hide Images
| 909634703 | matter | anything that occupies space and has mass | 0 | |
| 924559577 | mass | the actual amount of matter in an object; remains constant wherever the object is | 1 | |
| 924559578 | solids | have definite shape and volume | 2 | |
| 924559579 | liquids | have definite volume, but no definite shape; conform to the shape of the container | 3 | |
| 924559580 | gases | have neither definite volume nor shape | 4 | |
| 909634704 | energy | the capacity to do work or put matter into motion | 5 | |
| 909634705 | kinetic energy | the energy of motion or movement | 6 | |
| 909634706 | potential energy | stored or inactive energy | 7 | |
| 909634707 | chemical energy | energy stored in the bonds of chemical substances | 8 | |
| 909634708 | electrical energy | energy formed by the movement of charged particles across cell membranes | 9 | |
| 909634709 | mechanical energy | the energy directly involved in moving matter | 10 | |
| 909634710 | radiant (electromagnetic) energy | energy that travels in waves | 11 | |
| 909634711 | element | a unique substance that cannot be broken down into simpler substances by ordinary chemical methods; one of a limited number of unique varieties of matter that composes substances of all kinds | 12 | |
| 909634712 | periodic table | a listing of the known elements that helps to explain the properties of each element that make it react as it does with other elements | 13 | |
| 909634713 | atom | smallest particle of an elemental substance that exhibits the properties of that element | 14 | |
| 909634714 | physical properties | those properties we can detect with our senses or measure | 15 | |
| 909634715 | chemical properties | properties that pertain to the way atoms interact with other atoms | 16 | |
| 909634716 | atomic symbol | the one- or two-letter symbol used to indicate an element | 17 | |
| 909634717 | nucleus | contains protons and neutrons bound tightly together | 18 | |
| 909634718 | proton | subatomic particle that bears a positive charge; located in the atomic nucleus | 19 | |
| 909634719 | neutron | uncharged subatomic particle; found in the atomic nucleus | 20 | |
| 909634720 | atomic mass unit | the total number of protons and neutrons in an atomic nucleus | 21 | |
| 909634721 | electron | negatively charged subatomic particle; orbits the atom's nucleus | 22 | |
| 909634722 | planetary model | simplified model of atomic structure | 23 | |
| 909634723 | orbitals | regions around the nucleus of an atom in which the an electron or electron pair is likely to be found | 24 | |
| 909634724 | orbital model | model of atomic structure useful for predicting the chemical behavior of atoms | 25 | |
| 909634725 | atomic number | the number of protons in an atom | 26 | |
| 909634726 | mass number | sum of the number of protons and neutrons in the nucleus of an atom | 27 | |
| 909634727 | isotopes | different atomic forms of the same element, which vary only in the number of neutrons they contain | 28 | |
| 909634728 | atomic weight | the average of the mass numbers of all the isotopes of an element | 29 | |
| 909634729 | radioisotope | isotope that exhibits radioactive behavior | 30 | |
| 909634730 | molecule | particle consisting of two or more atoms joined together by chemical bonds | 31 | |
| 909634731 | compound | substance composed of two or more different elements, the atoms of which are chemically united | 32 | |
| 909634732 | mixtures | substances composed of two or more components physically intermixed | 33 | |
| 909634733 | solutions | homogeneous mixtures of components that may be gases, liquids, or solids | 34 | |
| 909634734 | homogeneous | the mixture has exactly the same composition or makeup throughout | 35 | |
| 909634735 | solvent | the substance present in the greatest amount in a solution | 36 | |
| 909634736 | solute | the substance that is dissolved in a solution | 37 | |
| 909634737 | percent | parts per 100 parts of the solute in the total solution | 38 | |
| 909634738 | molarity | moles per liter of solution | 39 | |
| 909634739 | mole | the atomic weight or molecular weight of any element measured in grams | 40 | |
| 909634740 | molecular weight | sum of the atomic weights | 41 | |
| 909634741 | Avogadro's number | the number of molecules in one mole of any substance, 6.02 × 10^23 | 42 | |
| 909634742 | colloid | a mixture in which the solute particles do not settle out readily | 43 | |
| 924559581 | heterogeneous | composition is dissimilar in different areas of the mixture | 44 | |
| 909634743 | sol-gel transformation | reversible change of a colloid from a fluid to a more solid state | 45 | |
| 909634744 | suspensions | heterogeneous mixtures with large, often visible solutes that tend to settle out | 46 | |
| 909634745 | chemical bond | an energy relationship holding atoms together; involves the interaction of electrons | 47 | |
| 909634746 | electron shells (energy levels) | regions of space that consecutively surround the nucleus of an atom | 48 | |
| 909634748 | valence shell | outermost electron shell of an atom that contains electrons | 49 | |
| 909634749 | octet rule (rule of eights) | the tendency of atoms to interact in such a way that they have eight electrons in their valence shell | 50 | |
| 909634750 | ion | atom with a positive or negative electric charge | 51 | |
| 909634751 | ionic bond | chemical bond formed by electron transfer between atoms | 52 | |
| 909634752 | anion | an ion carrying one or more negative charges and therefore attracted to a positive pole; gains one or more electrons; electron aceptor | 53 | |
| 909634753 | cation | an ion with a positive charge; loses electrons; electron donor | 54 | |
| 909634754 | crystals | large arrays of cations and anions held together by ionic bonds | 55 | |
| 909634755 | covalent bond | chemical bond created by electron sharing between atoms | 56 | |
| 909634756 | nonpolar molecules | electrically balanced molecules | 57 | |
| 909634757 | polar molecules (dipoles) | nonsymmetrical molecules that contain electrically unbalanced atoms | 58 | |
| 909634758 | electronegativity | the ability to attract electrons very strongly | 59 | |
| 909634759 | electropositive | electron-attracting ability is so low, valence shell electrons are usually lost to other atoms | 60 | |
| 909634761 | chemical reaction | process in which molecules are formed, changed, or broken down | 61 | |
| 909634762 | reactant | a substance taking part in a chemical reaction | 62 | |
| 909634763 | product | the substance formed in a chemical reaction | 63 | |
| 909634764 | molecular formula | a formula giving the number of atoms in each of the elements present in one molecule of a specific compound | 64 | |
| 909634765 | synthesis (combination) reaction | a chemical reaction in which larger, more complex atoms or molecules are formed from simpler ones | 65 | |
| 909634766 | anabolic | the build-up of simpler substances to combine to form more complex substances | 66 | |
| 909634767 | decomposition reaction | chemical reaction in which a molecule is broken down into smaller molecules or its constituent atoms | 67 | |
| 909634768 | catabolic | the break-down of substances into simpler substances | 68 | |
| 909634769 | exchange (displacement) reaction | chemical reaction in which bonds are both made and broken; atoms become combined with different atoms | 69 | |
| 909634770 | oxidation-reduction (redox) reaction | a reaction that couples the oxidation of one substance with the reduction of another substance | 70 | |
| 909634771 | oxidized | reactant loses electrons; electron donor | 71 | |
| 909634772 | reduced | reactant takes up transferred electrons; electron acceptor | 72 | |
| 909634773 | exergonic reaction | chemical reaction the releases energy | 73 | |
| 909634774 | endergonic reaction | chemical reaction that absorbs energy | 74 | |
| 909634775 | chemical equilibrium | a state of apparent repose created by two reactions proceeding in opposite directions at equal speed | 75 | |
| 909634776 | catalyst | substance that increases the rate of a chemical reaction without itself becoming chemically changed or part of the product | 76 | |
| 925545464 | biochemistry | the study of the chemical composition and reactions of living matter | 77 | |
| 909634777 | organic compound | any compound composed of atoms (some of which are carbon) held together by covalent bonds | 78 | |
| 909634778 | inorganic compound | chemical substances that do not contain carbon | 79 | |
| 909634779 | universal solvent | water is an unparalleled solvent | 80 | |
| 909634780 | hydration layers | layers of water molecules around large charged molecules | 81 | |
| 909634781 | hydrolysis reaction | adding a water molecule to each bond to be broken | 82 | |
| 909634782 | dehydration synthesis | process by which a large molecule is synthesized by removing water and covalently bonding smaller molecules together | 83 | |
| 909634783 | salt | an ionic compound containing cations other than H+ and anions other than OH- | 84 | |
| 909634784 | electrolytes | chemical substances that ionize and dissociate in water and are capable of conducting an electrical current | 85 | |
| 909634785 | acid | a substance that releases hydrogen ions when in solution; a proton donor | 86 | |
| 909634786 | hydrogen ions (H+) ions | a hydrogen atom minus its electron and therefore carrying a positive charge | 87 | |
| 909634787 | proton donor | a substance that releases hydrogen ions in detectable amounts; an acid | 88 | |
| 909634788 | base | a substance capable of binding with hydrogen ions; a proton acceptor | 89 | |
| 909634789 | proton acceptor | a substance that takes up hydrogen ions in detectable amounts; a base | 90 | |
| 909634790 | hydroxyl ion (OH-) | an ion liberated when a hydroxide is dissolved in water | 91 | |
| 909634791 | bicarbonate ion (HCO3-) | an important base in the body that is particularly abundant in blood | 92 | |
| 909634792 | ammonia (NH3) | common waste product of protein breakdown in the body; a proton acceptor/base | 93 | |
| 909634793 | pH unit | the measure of the relative acidity or alkalinity of a solution | 94 | |
| 909634794 | neutralization reaction | displacement reaction in which mixing an acid and a base forms water and a salt | 95 | |
| 909634795 | buffer | chemical substance or system that minimizes changes in pH by releasing or binding hydrogen ions | 96 | |
| 909634796 | strong acid | acid that dissociates completely and irreversibly in water | 97 | |
| 909634797 | weak acid | acid that does not dissociate completely in water | 98 | |
| 909634798 | strong base | base that dissociates easily in water | 99 | |
| 909634799 | weak base | base that ionizes incompletely and irreversibly | 100 | |
| 909634800 | carbonic acid-bicarbonate system | chemical system that helps maintain pH homeostasis of the blood | 101 | |
| 909634801 | electroneutral | never loses or gains electron, always shares them | 102 | |
| 909634802 | polymer | a substance of high molecular weight with long, chainlike molecules consisting of many similar units | 103 | |
| 909634803 | monomer | similar units that make up polymers | 104 | |
| 909634804 | carbohydrate | organic compound composed of carbon, hydrogen, and oxygen | 105 | |
| 909634805 | monosaccharide | building block of carbohydrates; single-chain or single-ring structures containing from three to seven carbon atoms | 106 | |
| 909634806 | isomer | one of two or more substances that has the same molecular formula but with its atoms arranged differently | 107 | |
| 909634807 | disaccharide | double sugar; formed when two monosaccharides are joined by dehydration synthesis | 108 | |
| 909634808 | sucrose | glucose + fructose | 109 | |
| 909634809 | lactose | glucose + galactose | 110 | |
| 909634810 | maltose | glucose + glucose | 111 | |
| 909634811 | polysaccharide | a polymer of linked monosaccharides | 112 | |
| 909634812 | lipid | organic compound formed of carbon, hydrogen, and oxygen | 113 | |
| 909634813 | triglycerides (neutral fats) | fats and oils composed of fatty acids and glycerol | 114 | |
| 909634814 | fatty acids | linear chains of carbon and hydrogen atoms (hydrocarbon chains) with an organic acid group at one end | 115 | |
| 909634815 | glycerol | A modified simple sugar; a building block of fats | 116 | |
| 909634816 | saturated fat | fatty acid chains with only single covalent bonds between carbon atoms | 117 | |
| 909634817 | unsaturated fat | fatty acids that contain one or more double bonds between carbon atoms | 118 | |
| 909634818 | monounsaturated fat | fatty acids that contain one double bond between carbon atoms | 119 | |
| 909634819 | polyunsaturated fat | fatty acids that contain multiple double bonds between carbon atoms | 120 | |
| 909634820 | trans fat | oils that have been solidified by addition of H atoms at sites of carbon double bonds | 121 | |
| 909634822 | phospholipid | modified lipid that contains phosphorus | 122 | |
| 909634823 | steroid | group of chemical substances including certain hormones and cholesterol; they are fat soluble and contain little oxygen | 123 | |
| 909634824 | eicosanoids | diverse lipids chiefly derived from a 20-carbon fatty acid found in all cell membranes | 124 | |
| 909634825 | protein | organic compound composed of carbon, oxygen, hydrogen, and nitrogen | 125 | |
| 909634826 | amino acid | organic compound containing nitrogen, carbon, hydrogen, and oxygen; building block of protein | 126 | |
| 909634827 | peptide bond | bond joining the amine group of one amino acid to the acid carboxyl group of a second amino acid with the loss of a water molecule | 127 | |
| 909634828 | macromolecules | Large, complex molecules containing from 100 to over 10,000 subunits | 128 | |
| 909634829 | alpha helix | the most common type of secondary structure of the amino acid chain in proteins; resembles the coils of a telephone cord | 129 | |
| 909634831 | fibrous (structural) proteins | consist of extended, strandlike polypeptide chains forming a strong, ropelike structure that is linear, insoluble in water, and very stable | 130 | |
| 909634833 | globular (functional) proteins | compact, spherical proteins that have at least tertiary structure | 131 | |
| 909634835 | denatured | hydrogen bonds begin to break when the pH drops or the temperature rises above normal levels, causing proteins to unfold and lose their specific three-dimensional shape | 132 | |
| 909634836 | active site | region on the surface of a functional (globular) protein where it binds and interacts chemically with other molecules of complementary shape and charge | 133 | |
| 909634837 | molecular chaperones | a class of unrelated globular proteins that help proteins to achieve their functional three dimensional structure | 134 | |
| 909634838 | enzyme | a protein that acts as a biological catalyst to speed up a chemical reaction | 135 | |
| 909634839 | holoenzyme | the functional enzyme consisting of the apoenzyme and the cofactor | 136 | |
| 909634840 | apoenzyme | the protein portion of an enzyme | 137 | |
| 909634841 | cofactor | metal ion or organic molecule that is required for enzyme activity | 138 | |
| 909634842 | coenzyme | nonprotein substance associated with and activating an enzyme | 139 | |
| 909634843 | substrate | a reactant on which an enzyme acts to cause a chemical action to proceed | 140 | |
| 909634844 | activation energy | the amount of energy required to push a reactant to the level necessary for action | 141 | |
| 909634845 | nucleic acid | class of organic molecules that includes DNA and RNA | 142 | |
| 909634846 | deoxyribonucleic acid (DNA) | a nucleic acid found in all living cells; it carries the organism's hereditary information | 143 | |
| 909634847 | ribonucleic acid (RNA) | nucleic acid that contains ribose and the bases A, G, C, and U; carries out instructions for protein synthesis | 144 | |
| 909634848 | nucleotide | building block of nucleic acids; consists of a sugar, a nitrogen-containing base, and a phosphate group | 145 | |
| 909634849 | adenine (A) | one of the two major purines found in both RNA and DNA; also found in various free nucleotides of importance to the body, such as ATP | 146 | |
| 909634850 | guanine (G) | one of two major purines occurring in all nucleic acids | 147 | |
| 909634851 | cytosine (C) | nitrogen-containing base that is part of a nucleotide structure | 148 | |
| 909634852 | thymine (T) | single-ring base (a pyrimidine) in DNA | 149 | |
| 909634853 | uracil (U) | a smaller, single-ring base (a pyrimidine) found in RNA | 150 | |
| 909634854 | double helix | the secondary structure assumed by two strands of DNA, held together throughout their length by hydrogen bonds between bases on opposite strands | 151 | |
| 909634855 | complementary base | refers to how a given nitrogenous base of DNA or RNA bonds to another nitrogenous base | 152 | |
| 909634856 | adenosine triphosphate (ATP) | organic molecule that stores and releases chemical energy for use in body cells | 153 |
