Term
|
Definition
| the capacity to perform work, or to rearrange matter. |
|
|
Term
|
Definition
| the energy of motion; the energy of a mass of matter that is moving. Moving matter performs work by transferring its motion to other matter, such as leg muscles pushing bicycle pedals. |
|
|
Term
|
Definition
| thermal energy; the amount of energy associated with the movement of the atoms and molecules in a body of matter. Heat is energy in its most random form. |
|
|
Term
|
Definition
| stored energy; the capacity to perform work that matter possesses because of its location or arrangement. Water behind a dam and chemical bonds possess potential energy. |
|
|
Term
|
Definition
| energy stored in the chemical bonds of molecules; a form of potential energy. |
|
|
Term
|
Definition
the study of energy transformations that occur in a collection of matter. See... first law of thermodynamics; second law of thermodynamics |
|
|
Term
| first law of thermodynamics |
|
Definition
| the natural law stating that the total amount of energy in the universe is constant and that energy can be transferred and transformed, but never destroyed; also called the principle of energy conservation. |
|
|
Term
|
Definition
| a measure of disorder. One form of disorder is heat, which is random molecular motion. |
|
|
Term
| second law of thermodynamics |
|
Definition
| the natural law stating that energy conversions reduce the order of the universe, increasing its energy. |
|
|
Term
|
Definition
| an energy-requiring chemical reaction, which yields products with more potential energy than the reactants. The amount of energy stored in the products equals the difference between the potential energy in the reactants and that in the products. |
|
|
Term
|
Definition
| an energy-realeasing chemical reaction in which the reactants contain more potential energy than the products. The reaction releases an amount of energy equal to the difference in potential energy between the reactants and the products. |
|
|
Term
|
Definition
| the aerobic harvesting of energy from food molecules; the energy-releasing chemical breakdown of food molecules, such as glucose, and the storage of potential energy in a form that cells can use to perform work; involves glycolysis, the citric ancid cycle, and oxidative phosphorylation (the electron transport chain and the chemiosmosis). |
|
|
Term
|
Definition
the chemical activities of cells. |
|
|
Term
|
Definition
in cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction. |
|
|
Term
|
Definition
| adenosine triphosphate, the main energy source for cells. |
|
|
Term
|
Definition
| the transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules by phosphorylation. |
|
|
Term
| energy of activation (EA) |
|
Definition
| the amount of energy that reactants must absorb before a chemical reaction will start. |
|
|
Term
|
Definition
a protein that serves as a biological catalyst, changing the rate of a chemical reaction without itself being changed into a different molecules in the process. |
|
|
Term
|
Definition
(1) A specific substance (reactant) on which an enzyme acts. Each enzyme recognizes only the specific substrate or substrated of the reaction it catalyzes. (2) A surface in or on which an organism lives. |
|
|
Term
|
Definition
| the part of an enzyme molecule where a substrate molecule attaches (by means of weak chemical bonds); typically, a pocket or grrove on the enzyme's surface. |
|
|
Term
|
Definition
| the interaction between a substrate molecule and the active site of an enzyme, which changes shape slightly to embrace the substrate and catalyze the reaction. |
|
|
Term
|
Definition
| a nonprotein substance (such as a copper, iron, or zinc atom or an organic mlecule) that helps an enzyme catalyze a metabolic reaction. |
|
|
Term
|
Definition
| an organic molecule (usually a vitamin or a compound synthesized from a vitamin) that acts as a cofact, helping an enzyme catalyze a metabolic reaction. |
|
|
Term
|
Definition
| a substance that reduces the activity of an enzyme by binding to the enzyme's active site in place of the substrate. A competitive inhibitor's structure mimics that of the enzyme's substrate. |
|
|
Term
|
Definition
| a substance that impedes the activity of an enzyme without entering an active site and thus without competing directly with the normal substrate. By binding elsewhere on the enzyme, a noncompetitive inhibitor changes the shape of the enzyme so that the active site no longer functions. |
|
|
Term
|
Definition
| a method of metabolic control in which a product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway, thereby blocking the metabolic reaction. |
|
|
