Chapter 8

Question 1

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.

Answer 1

Active Site

Question 2

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

Answer 2

Metabolism

Question 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.

Answer 3

Feedback Inhibition

Question 4

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

Answer 4

Metabolic Pathway

Question 5

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.

Answer 5

Cooperativity

Question 6

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

Answer 6

Catabolic Pathway

Question 7

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

Answer 7

Allosteric Regulation

Question 8

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

Answer 8

Anabolic Pathway

Question 9

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.

Answer 9

Noncompetitive Inhibitors

Question 10

The energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter.

Answer 10

Kinetic Energy

Question 11

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

Answer 11

Coenzyme

Question 12

The total amount of kinetic energy due to the random motion of atoms or molecules in a body of matter; also called heat.

Answer 12

Thermal Energy

Question 13

Any nonprotein molecule or ion that is required for the proper functioning of an enzyme.

Answer 13

Cofactors

Question 14

The energy that matter possesses as a result of its location or spatial arrangement (structure).

Answer 14

Potential Energy

Question 15

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.

Answer 15

Induced Fit

Question 16

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

Answer 16

Chemical Energy

Question 17

The reactant on which an enzyme works.

Answer 17

Substrate

Question 18

The study of energy transformations that occur in a collection of matter.

Answer 18

Thermodynamics

Question 19

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

Answer 19

Activation Energy

Question 20

The principle of conservation of energy: Energy can be transferred and transformed, but it cannot be created or destroyed.

Answer 20

First Law of Thermodynamics

Question 21

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

Answer 21

Catalyst

Question 22

A measure of disorder, or randomness.

Answer 22

Entropy

Question 23

A macromolecule serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction.

Answer 23

Enzyme

Question 24

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.

Answer 24

Second Law of Thermodynamics

Question 25

Referring to a molecule that is covalently bonded to a phosphate group.

Answer 25

Phosphorylated

Question 26

The portion of a biological system’s energy that can perform work when temperature and pressure are uniform throughout the system.

Answer 26

Free Energy

Question 27

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed.

Answer 27

ATP

Question 28

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

Answer 28

Exergonic Reaction

Question 29

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

Answer 29

Energy Coupling

Question 30

A non-spontaneous chemical reaction, in which free energy is absorbed from the surroundings.

Answer 30

Endergonic Reaction

Question 31

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

Answer 31

Energy

Question 32

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

Answer 32

Competitive Inhibitors