Question | Answer |
Ionic bonds | bonds when electrons are transferred; typically between metals and nonmetals |
Covalent bonds | bonds that form when electrons are shared; typically between nonmetals |
Nonpolar covalent bonds | bonds that form when electrons are shared equally |
Hydrogen bonds | positively charged hydrogen atom in one covalent molecule is attracted to a negatively charged area of another |
Hydrophobic | nonpolar covalent substances that do not dissolve in water; “water fearing” |
Hydrophillic | polar substances; “water loving” |
Heat capacity | the degree to which a substance changes temperature in response to a gain or loss of heat |
Cohesion | the attraction between like substances |
Adhesion | the attraction of unlike substances |
capillary action | when water adheres to the walls of narrow tubing or to absorbent solids like paper |
Organic molecules | have carbon atoms |
Macromolecules | consist of hundreds or thousands of atoms |
Polymer | a single unit repeated many times |
Monomer | a single unit |
monosaccharide | a single sugar molecule |
disaccharide | two sugar molecules joined by a glycosidic linkage |
dehydration synthesis | The chemical process by which a molecule of water is removed from the reactants to join the reactants together |
polysaccharide | a series of connected monosaccharides |
Starch | a polymer of alpha glucose molecules produced by plants |
Glycogen | a polymer of alpha glucose molecules; energy storage molecule in animal cells. |
Cellulose | a polymer of beta glucose molecules; structural molecule in the walls of plant cells |
Chitin | polymer of beta glucose molecules with nitrogen |
Triglycerides | fats and oils, they consist of three fatty acids attached to a glycerol molecule |
saturated fatty acid | has a single covalent bond between each pair of carbon atoms |
monounsaturated fatty acid | has one double covalent bond |
polyunsaturated fatty acid | two or more double covalent bonds |
phospholipid | a lipid except that has one of the fatty acid chains replaced by a phosphate group |
amphipathic molecule | has both polar (hydrophilic) and nonpolar (hydrophobic) regions |
Steroids | have a backbone of four linked carbon rings. Ex. cholesterol and certain hormones |
Enzymes | globular proteins that act as catalysts for metabolic reactions |
Defensive proteins | provide protection against foreign substances that enter the bodies of animals |
Transport proteins | transport materials into and out of cells |
amino acids | monomers of proteins, consist of an amino group (NH2), a carboxyl group (COOH), and a functional group |
primary structure | the sequence of amino acids in a protein |
secondary structure | hydrogen bonding produces a alpha helix and beta pleated sheet |
tertiary structure | 3D shaping due to interactions between functional groups |
quaternary structure | structure of a protein assembled from two or more separate peptide chains |
DNA | deoxyribonucleic acid, a polymer of nucleic acids |
Nucleotide | consists of three parts: a nitrogen base, a five |
Adenine | a double ring base (purine) |
Thymine | a single ring base (pyrimidine) |
Cytosine | a single ring base (pyrimidine) |
Guanine | a double ring base (purine) |
Pyrimidines | single ring nitrogenous base |
Purines | double ring nitrogenous base |
RNA | ribonucleic acid |
Uracil | single ring base (pyrimidine) |
activation energy | energy required to trigger the formation of new bonds |
catalyst | accelerates the rate of the reaction by lowering the activation energy |
metabolism | Chemical reactions that occur in biological systems |
catabolism | the breakdown of substances |
anabolism | the formation of new products (synthesis) |
substrate | the substance or substances upon which the enzyme acts |
induced fit model | The active site binds to the substrate, causes the enzyme to change shape which results in a change in substrate |
Cofactors | nonprotein molecules that assist enzymes |
Coenzymes | organic cofactors that usually function to donate or accept some component of a reaction. |
Inorganic cofactors | often metal ions, like Fe2+ and Mg2+ |
ATP | (adenosine triphosphate) a common source of energy for metabolism, basically an adenine and 3 phosphate groups |
Phosphorylation | when a molecule combines with a phosphate group using energy |
Allosteric enzymes | have two kinds of binding sites; one an active site for the substrate and one for an allosteric effector. |
allosteric activator | binds to the enzyme and induces the enzyme’s active form |
allosteric inhibitor | binds to the enzyme and induces the enzyme’s inactive form |
feedback inhibition | an end product acts as an allosteric inhibitor, shutting down one of the enzymes |
competitive inhibition | mimics the substrate occupies the active site and prevents the enzyme from catalyzing the substrate |