| A | B |
|---|
| activation energy | amount of energy that reactants must absorb before a chemical reaction will start; also called activation energy |
| active site | specific portion of an enzyme that attaches to the substrate by means of weak chemical bonds |
| allosteric regulation | binding of a molecule to a protein that affects the function of the protein at a different site |
| anabolic pathway | metabolic pathway that synthesizes a complex molecule from simpler compounds |
| ATP (adenosine triphosphate) | adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed |
| bioenergetics | flow of energy through an animal |
| catabolic pathway | metabolic pathway that releases energy by breaking down complex molecules to simpler compounds |
| catalyst | chemical agent that changes the rate of a reaction without being consumed by the reaction |
| chemical energy | energy stored in the chemical bonds of molecules; a form of potential energy |
| coenzyme | organic molecule serving as a cofactor. Most vitamins function as coenzymes in important metabolic reactions |
| cofactor | non-protein molecule or ion that is required for the proper functioning of an enzyme |
| competitive inhibitor | substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics |
| cooperativity | interaction of the constituent subunits of a protein whereby a conformational change in one subunit is transmitted to all the others |
| endergonic reaction | non-spontaneous chemical reaction |
| energy | capacity to do work |
| energy coupling | the use of energy released from an exergonic reaction to drive an endergonic reaction |
| entropy | quantitative measure of disorder or randomness |
| enzyme | protein serving as a catalyst |
| enzyme-substrate complex | temporary complex formed when an enzyme binds to its substrate molecule(s) |
| exergonic reaction | spontaneous chemical reaction |
| feedback inhibition | control where the end product of pathway acts as an inhibitor of an enzyme within that pathway |
| first law of thermodynamics | energy can be transferred and transformed |
| free energy | energy that can perform work when temperature and pressure are uniform |
| free energy of activation | amount of energy that reactants must absorb before a chemical reaction will start; also called activation energy |
| heat | total amount of kinetic energy due to molecular motion in a body of matter |
| induced fit | change in shape of the active site so that it binds more snugly to substrate |
| kinetic energy | energy of motion |
| metabolic pathway | series of chemical reactions that either builds or breaks down a complex molecule |
| metabolism | totality of an organism’s chemical reactions |
| non-competitive inhibitor | reduces the activity of enzyme by binding to a location remote from the active site |
| phosphorylated | molecule that has been the recipient of a phosphate group |
| potential energy | energy stored by matter as a result of its location or spatial arrangement |
| second law of thermodynamics | energy transformations result in less usable forms of energy |
| substrate | reactant on which an enzyme works |
| thermal energy | total amount of kinetic energy due to molecular motion in a body of matter |
| thermodynamics | study of energy transformations that occur in matter |
