Chapter 8 Flashcards
The specific portion of an enzyme that binds the substrate by means of multiple weak interactions and that forms the pocket in which catalysis occurs.
Active Site
The totality of an organism’s chemical reactions, consisting of catabolic and anabolic pathways, which manage the material and energy resources of the organism.
Metabolism
A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.
Feedback Inhibition
A series of chemical reactions that either builds a complex molecule (anabolic pathway) or breaks down a complex molecule into simpler compounds (catabolic pathway).
Metabolic Pathway
A kind of allosteric regulation whereby a shape change in one subunit of a protein caused by substrate binding is transmitted to all the others, facilitating binding of subsequent substrate molecules.
Cooperativity
A metabolic pathway that releases energy by breaking down complex molecules to simpler compounds.
Catabolic Pathway
The binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site.
Allosteric Regulation
A metabolic pathway that consumes energy to synthesize a complex molecule from simpler compounds.
Anabolic Pathway
A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing the enzyme’s shape so that the active site no longer functions effectively.
Noncompetitive Inhibitors
The energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter.
Kinetic Energy
An organic molecule serving as a cofactor. Most vitamins function as these in metabolic reactions.
Coenzyme
The total amount of kinetic energy due to the random motion of atoms or molecules in a body of matter; also called heat.
Thermal Energy
Any nonprotein molecule or ion that is required for the proper functioning of an enzyme.
Cofactors
The energy that matter possesses as a result of its location or spatial arrangement (structure).
Potential Energy
Induced by entry of the substrate, the change in shape of the active site of an enzyme so that it binds more snugly to the substrate.
Induced Fit
Energy available in molecules for release in a chemical reaction; a form of potential energy.
Chemical Energy
The reactant on which an enzyme works.
Substrate
The study of energy transformations that occur in a collection of matter.
Thermodynamics
The amount of energy that reactants must absorb before a chemical reaction will start; also called free energy of activation.
Activation Energy
The principle of conservation of energy: Energy can be transferred and transformed, but it cannot be created or destroyed.
First Law of Thermodynamics
A chemical agent that increases the rate of a reaction without being consumed by the reaction.
Catalyst
A measure of disorder, or randomness.
Entropy
A macromolecule serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction.
Enzyme
The principle stating that every energy transfer or transformation increases the entropy of the universe. Ordered forms of energy are at least partly converted to heat.
Second Law of Thermodynamics
Referring to a molecule that is covalently bonded to a phosphate group.
Phosphorylated
The portion of a biological system’s energy that can perform work when temperature and pressure are uniform throughout the system.
Free Energy
An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed.
ATP
A spontaneous chemical reaction, in which there is a net release of free energy.
Exergonic Reaction
In cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction.
Energy Coupling
A non-spontaneous chemical reaction, in which free energy is absorbed from the surroundings.
Endergonic Reaction
The capacity to cause change, especially to do work (to move matter against an opposing force).
Energy
A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.
Competitive Inhibitors
