Mastering Biology Chapter 8 Key Terms – Flashcards

The amount of energy required to initiate a chemical reaction; specifically, the energy required to reach the transition state

The location in an enzyme molecule where substrates (reactant molecules) bind and react

A molecule consisting of an adenine base, a sugar, and three phosphate groups that can be hydrolyzed to release energy. Universally used by cells to store and transfer energy

Any set of chemical reactions that synthesizes large molecules from smaller ones. Generally requires an input of energy

The use of living organisms, usually bacteria or archaea, to degrade environmental pollutants

Any set of chemical reactions that breaks down large, complex molecules into smaller ones, releasing energy in the process

A small organic molecule that is a required cofactor for an enzyme-catalyzed reaction. Often donates or receives electrons or functional groups during the reaction

An inorganic ion that is required for an enzyme to function normally

Inhibition of an enzyme's ability to catalyze a chemical reaction via binding of a non-reactant molecule that competes with the substrate(s) for access to the active site

A reactant that gains an electron and is reduced in a reduction-oxidation reaction

Any molecule that readily accepts electrons from and donates electrons to other molecules. Protons may be transferred with the electrons in the form of hydrogen atoms

A reactant that loses an electron and is oxidized in a reduction-oxidation reaction

Referring to a chemical reaction that requires an input of energy to occur and for which the Gibbs free-energy change (ΔG) is greater than zero

In cellular metabolism, the mechanism by which energy released from an exergonic reaction (commonly, hydrolysis of ATP) is used to drive an endergonic reaction

A quantitative measure of the amount of potential energy, or heat content, of a system plus the pressure and volume it exerts on its surroundings

A quantitative measure of the amount of disorder of any system, such as a group of molecules

Referring to a chemical reaction that can occur spontaneously, releasing heat and/or increasing entropy, and for which the Gibbs free energy change (ΔG) is less than zero

Referring to a chemical reaction that releases heat

Oxidized and reduced forms, respectively, of flavin adenine dinucleotide. A nonprotein electron carrier that functions in the citric acid cycle and oxidative phosphorylation

The energy of a system that can be converted into work. It may be measured only through the change in free energy in a reaction

A measure of the change in enthalpy and entropy that occurs in a given chemical reaction. ΔG is less than 0 for spontaneous reactions and greater than 0 for non-spontaneous reactions

Change in the shape of the active site of an enzyme, as the result of initial weak binding of a substrate, so that it binds substrate more tightly

A unit of energy often used to measure the energy content of food. A kcal of energy raises 1 kg of water 1°C

The energy of motion

Oxidized and reduced forms, respectively, of nicotinamide adenine dinucleotide. A nonprotein electron carrier that functions in many of the redox reactions of metabolism

The loss of electrons from an atom or molecule during a redox reaction, either by donation of an electron to another atom or molecule, or by the shared electrons in covalent bonds moving farther from the atomic nucleus

The addition of a phosphate group to a molecule

A non-amino acid atom or molecule that is permanently attached to an enzyme or other protein and is required for its function

Any chemical reaction that involves either the complete transfer of one or more electrons from one reactant to another, or a reciprocal shift in the position of shared electrons within one or more of the covalent bonds of two reactants

The gain of electrons by an atom or molecule during a redox reaction, either by acceptance of an electron from another atom or molecule, or by the shared electrons in covalent bonds moving closer to the atomic nucleus

The principle of physics that the entropy of the universe or any closed system always increases

A reactant that interacts with a catalyst, such as an enzyme or ribozyme, in a chemical reaction

A surface on which a cell or organism sits

A high-energy intermediate state of the reactants during a chemical reaction that must be achieved for the reaction to proceed