3-1 Vocab

Question 1

Endergonic Reaction

Answer 1

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

Question 2

Energy Coupling

Answer 2

In cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction

Question 3

Feedback Inhibition

Answer 3

A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway

Question 4

Enzyme

Answer 4

A macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction. Most enzymes are proteins

Question 5

Cofactors

Answer 5

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 and reversibly, along with the substrate, during catalysis

Question 6

Catalysis

Answer 6

A process by which a chemical agent called a catalyst selectively increases the rate of a reaction without being consumed by the reaction

Question 7

Coenzyme

Answer 7

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

Question 8

Competitive Inhibitors

Answer 8

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

Question 9

Active Site

Answer 9

The specific region of an enzyme that binds the substrate and that forms the pocket in which catalysis occurs

Question 10

Entropy

Answer 10

A measure of molecular disorder, or randomness

Question 11

Metabolism

Answer 11

The totality of an organism’s chemical reactions, consisting of catabolic and anabolic pathways, which manage the material and energy resources of the organism

Question 12

Noncompetitive Inhibitors

Answer 12

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 effectively catalyzes the conversion of substrate to product

Question 13

Metabolic Pathway

Answer 13

A series of chemical reactions that either builds a complex molecule (anabolic pathway) or breaks down a complex molecule to simpler molecules (catabolic pathway)

Question 14

Activation Energy

Answer 14

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

Question 15

Enzyme-Substrate Complex

Answer 15

A temporary complex formed when an enzyme binds to its substrate molecule(s)

Question 16

Induced Fit

Answer 16

Caused 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

Question 17

Substrate

Answer 17

The reactant on which an enzyme works

Question 18

Catabolic Pathways

Answer 18

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

Question 19

Exergonic Reaction

Answer 19

A spontaneous chemical reaction, in which there is a net release of free energy

Question 20

Anabolic Pathways

Answer 20

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