Chapter 8 Biology Vocabulary

The amount of energy that reactants must absorb before a chemical reaction will start; also called free energy of activation.

The specific portion of an enzyme that binds the substrate by means of multiple weak interactions and that form the pocket in which catalysis occurs.

The binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site.

A metabolic pathway that consumes energy to synthesize a complex molecule from simpler compounds.

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells.

(1) The overall flow and transformation of energy in an organism. (2) The study of how energy flows through organisms.

A metabolic pathway that releases energy by breaking down complex molecules to simpler compounds.

A chemical agent that increases the rate of a reaction without being consumed by the reaction.

Energy available in molecules for release in a chemical reaction; a form of potential energy.

An organic molecule serving as a cofactor. Most vitamins function as these in metabolic reactions.

Any nonprotein molecule or ion that is required for the proper functioning of an enzyme. Cofactors can be permanently bound to the active site or may bind loosely with the substrate during catalysis.

A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.

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.

A nonspontaneous chemical reaction, in which free energy is absorbed from the surroundings.

The capacity to cause change, especially to do work (to move matter against an opposing force).